eProsima Fast DDS Monitor Documentation

eProsima Fast DDS Monitor is a graphical desktop application aimed at monitoring DDS environments deployed using the eProsima Fast DDS library. Thus, the user can monitor in real time the status of publication/subscription communications between DDS entities. They can also choose from a wide variety of communication parameters to be measured (latency, throughput, packet loss, etc.), as well as record and compute in real time statistical measurements on these parameters (mean, variance, standard deviation, etc.).

Furthermore, the user can check the status of the deployed DDS network at any time, i.e. see for each DDS Domain which DomainParticipants are instantiated, as well as their publishers and subscribers and the topics under which they publish or to which they subscribe respectively. It is also possible to see the physical architecture of the network on which the DDS applications that use Fast DDS are running.

eProsima Fast DDS Monitor is designed to meet the following criteria:

Monitoring: real-time tracking of network status and DDS communication.
Intuitive: graphical user interface developed following a user experience design approach.
Introspection: easily navigate through the deployed and active DDS entities being able to inspect their configuration and physical deployment.
Troubleshooting: detect at a glance the possible issues or anomalous events that may occur in the communication.

Warning

In order to monitor a DDS network deployed using Fast DDS library, compiling the latter with statistics and explicitly activating the statistics module is required. See Fast DDS with Statistics module for more details.

Warning

If Fast DDS has been compiled with statistics and they are explicitly enabled and statistical data are not correctly received, only few data arrive or even none, configure the Fast DDS endpoints publishing statistics data with a less restrictive memory constraints. Please check the following documentation for more details on how to do this.

Contacts and Commercial support¶

Find more about us at eProsima’s webpage.

Support available at:

Email: support@eprosima.com
Phone: +34 91 804 34 48

Contributing to the documentation¶

Fast DDS Monitor Documentation is an open source project, and as such all contributions, both in the form of feedback and content generation, are most welcomed. To make such contributions, please refer to the Contribution Guidelines hosted in our GitHub repository.

Structure of the documentation¶

This documentation is organized into the sections below.

eProsima Fast DDS Monitor Documentation

eProsima Fast DDS Monitor is a graphical desktop application aimed at monitoring DDS environments deployed using the eProsima Fast DDS library. Thus, the user can monitor in real time the status of publication/subscription communications between DDS entities. They can also choose from a wide variety of communication parameters to be measured (latency, throughput, packet loss, etc.), as well as record and compute in real time statistical measurements on these parameters (mean, variance, standard deviation, etc.).

Furthermore, the user can check the status of the deployed DDS network at any time, i.e. see for each DDS Domain which DomainParticipants are instantiated, as well as their publishers and subscribers and the topics under which they publish or to which they subscribe respectively. It is also possible to see the physical architecture of the network on which the DDS applications that use Fast DDS are running.

eProsima Fast DDS Monitor is designed to meet the following criteria:

Monitoring: real-time tracking of network status and DDS communication.
Intuitive: graphical user interface developed following a user experience design approach.
Introspection: easily navigate through the deployed and active DDS entities being able to inspect their configuration and physical deployment.
Troubleshooting: detect at a glance the possible issues or anomalous events that may occur in the communication.

Warning

In order to monitor a DDS network deployed using Fast DDS library, compiling the latter with statistics and explicitly activating the statistics module is required. See Fast DDS with Statistics module for more details.

Warning

If Fast DDS has been compiled with statistics and they are explicitly enabled and statistical data are not correctly received, only few data arrive or even none, configure the Fast DDS endpoints publishing statistics data with a less restrictive memory constraints. Please check the following documentation for more details on how to do this.

Contacts and Commercial support¶

Find more about us at eProsima’s webpage.

Support available at:

Email: support@eprosima.com
Phone: +34 91 804 34 48

Contributing to the documentation¶

Fast DDS Monitor Documentation is an open source project, and as such all contributions, both in the form of feedback and content generation, are most welcomed. To make such contributions, please refer to the Contribution Guidelines hosted in our GitHub repository.

Structure of the documentation¶

This documentation is organized into the sections below.

Fast DDS Monitor on Windows¶

This section provides instructions on how to install the Fast DDS Monitor application. This is available on the eProsima website in the Downloads section.

In the list of eProsima official releases, search for eProsima Fast DDS Monitor and go to the available files of the latest version available. Then click on the Download now button of the Windows installer (eProsima Fast DDS Monitor x.x.x - Win (32 & 64)).

Now locate the downloaded file and run the installer. The Fast DDS Monitor installer window should open as shown in the following image.

Follow the installation steps until the installation process is complete. A window as the one shown below should be visible on screen after installation, from which you may directly run the Fast DDS Monitor application.

Fast DDS Monitor on Linux¶

This section provides instructions on how to install the Fast DDS Monitor application. This is available on the eProsima website in the Downloads section.

There are two mechanisms for running the monitor application.

Through the Fast DDS Monitor installer.
Using the AppImage format, which is a portable format of the application software.

Fast DDS Monitor installer¶

The first option is to install the Fast DDS monitor application together with all its dependencies. To do so, first run the FastDDSMonitorInstaller.run executable and follow the instructions it provides to install the program in a directory on the system.

Fast DDS Monitor portable format¶

eProsima also distributes a portable version of the Fast DDS Monitor for Linux in AppImage format. In this case, download this version from the eProsima Downloads website and run the downloaded file to launch the monitor. The name of this file is Fast_DDS_Monitor-x86_64-X.X.X.AppImage, where X.X.X is the version of the application.

Warning

In case these files are not executed, check that they have executable permissions.

Entities¶

The monitoring functions of this application relay on tracking the activity of certain Entities retrieved by the Fast DDS Monitor, as well as on storing connections and interchanged data between them for their presentation to the user. These entities represent DDS communication entities, or different physical elements related to DDS entities.

In the following diagram one can see the different kinds of entities being tracked by the monitor. The arrows in this schema represent a direct connection (not a 1:n in every case) between both kinds of entities. Those entities (or types of entities) that do not have a direct relationship are also related, as intermediate entities make it possible to relate any entity in the graph to one another indirectly, i.e. one DomainParticipant is related with its User by the relation with its Process.

DDS Entities¶

These entities represent the DDS entities that manage the communication. That is, the DomainParticipants, DataWriters and DataReaders. Each DataReader/DataWriter has one or more associated Locator entities. Locators are the network addresses through which DataReaders/DataWriters communicate in a DDS network.

For further information about each entity, please refer to the DDS specification or visit the Fast DDS Documentation.

DomainParticipant¶

DomainParticipant is the main entity in the DDS protocol. It represents a collection of DataReaders/DataWriters, and manage the whole DDS Discovery of other DomainParticipants and DataReaders/DataWriters within the DDS Domain to which it belongs. Refer to DomainParticipant Fast DDS Documentation for a more detailed explanation of the DomainParticipant entity in DDS.

Each DomainParticipant can only communicate under one Domain (see Logical Entities) and so it exists a direct connection between each DomainParticipant and the Domain in which it works. From image fig_entities_diagram it can be seen that DomainParticipant entities are contained in a Process, this is because a system process (so-called Process entity) executes an application using Fast DDS that instantiates DomainParticipants. The same applies to DataReaders/DataWriters instantiated by a DomainParticipant belonging to a specific Process. Therefore, a Process can contain as many DDS entities as the Fast DDS application running in that Process has instantiated.

DataWriter¶

DataWriter is the DDS entity in charge of publishing data. Each DataWriter is directly contained in a single DomainParticipant. In addition, since a DataWriter is associated to the Topic under which it publishes, it is possible to define a direct containment relationship of a DataWriter in a Topic. Thus, the Topic will contain all the DataWriters that are publishing under it.

Therefore, each DataWriter is directly connected with the DomainParticipant it belongs, and with the Topic under which it publishes. Also, a DataWriter is associated with one or multiple Locators that would represent the physical communication channel this DataWriter is using to send data.

DataReader¶

DataReader holds the subscribe function of the communication. As for the DataWriter, each DataReader is directly contained in a single DomainParticipant. In addition, since a DataReader is associated to the Topic to which it is subscribed, it is possible to define a direct containment relationship of a DataReader in a Topic. Thus, the Topic will contain all the DataReaders that are subscribed under it. Therefore, each DataReader is directly connected with the DomainParticipant to which it belongs, and with the Topic to which it is subscribed.

Locator¶

Locator represents the physical address and port that a DataReader/DataWriter uses to send or/and receive data. This entity is related with the physical division of the entities, as a Locator belongs to a unique Host (see section Physical Entities). However, the monitor treats this entity as a DDS Entity in order to simplify the entities’ connection and improve comprehensibility.

A Locator is connected with one or multiple DataReader/DataWriter, and so it is related with a Host by relating each of these DataReader/DataWriter with a DomainParticipant and each DomainParticipant with its Host.

Logical Entities¶

Domain¶

Domain represents a logical abstraction in DDS protocol that divides the DDS network into partitions, making each Domain completely independent and unaware of others. This logical partition depends on the chosen discovery protocol.

In case of using Simple Discovery Protocol (discovery protocol by default in Fast DDS) as the default discovery mechanism, the Domain will be represented by a number (domain ID), and every DDS entity in that Domain will discover the rest of entities deployed on the same Domain. In case of using Discovery Server as discovery protocol, the partition will be made by the Discovery Server or Discovery Servers Net to which the monitor connects. Please refer to Fast DDS documentation for more information about this feature. Each entity connected to a Discovery Server on the same network will know all other entities with which it needs to communicate.

This entity inside the monitor is related with the DomainParticipants that communicate under this same Domain, and the Topics created in this Domain.

Topic¶

Topic is an abstract DDS entity that represents the channel of communications between publishers and subscribers. Every DataReader subscribed to a Topic will receive the publications of every DataWriter publishing under the same Topic.

This entity inside the monitor is directly connected with the Domain it belongs to, and with the DataReaders/DataWriters communicating under this Topic.

Physical Entities¶

Host¶

Host makes reference to the physical (or logical i.e. Docker) machine where one or more DDS Processes are running. This entity is connected directly with the Users running in this Host.

User¶

User makes reference to the different users that could run in a Host.

This entity is connected directly with the Host it belongs to, and the running Processes that are being executed within this User.

Process¶

Process represents each process running an application using Fast DDS. Be aware that it is possible to run more than one DomainParticipant in the same Process, and they do not require to be related with each other, not even under the same Domain.

This entity is connected directly with the User to which it belongs, and the Participants running within it.

Monitor Domain¶

This application is able to track different Entities that belongs to the DDS communication protocol or are, in some sense, related to these entities. The DDS communication protocol (see DDS specification) divide a DDS network in independent partitions referred to as Domain. This Domains must fulfilled that only the entities in the same Domain can discover and communicate with each other, and so this depends on the Discovery Protocol that is being use. This application implements two different Discovery Protocols that could be use to monitor entities.

Several Domains could be monitored at the same time and the Logical Entities and the DDS Entities under one Domain would never be shared between others (except for Locator). This is not the case with the Physical Entities that could be shared between entities in different domains, as the same Host, or even the same Locator could be related with entities in several Domains.

For the propose of monitoring a Domain, the application gives the button Initialize Monitor where a user can manually specify the configuration of a Discovery type. Once a Monitor is initialized in a specific Domain, the entities in this Domain will start to be discovered and its data collected. Every new entity or data discovered will be notified as a callback in Issues Panel.

Note

Be aware that the discovery of the Fast DDS Monitor entities is made by DDS protocols, and so they will not be instantaneous or simultaneous.

Simple Discovery Monitor¶

The DDS Simple Discovery Protocol (SDP) remains on the discovery of individual entities by multicast communication. No previous information about the network and its architecture is needed in order to create a new monitor that connects with the Participants already running in the same network. In order to configure this kind of Domain monitoring, it is only needed to specify the number of the Domain that is going to be tracked

Discovery Server Monitor¶

The Discovery Server discovery protocol is a Fast DDS feature that allows to centralize the discovery phase in a single or a network of Discovery Servers. This has been demonstrated to be very useful in order to reduce the discovery traffic and to avoid certain problems that could appear with the Simple Discovery Protocol and multicast.

In order to configure this kind of Domain monitoring, it is required to insert a string with different network addresses. This string consist in one or several addresses in the format of ip_address:port. Each of these are IP-port pair where a Discovery Server is listening. Each network address is separated with ;. It is only needed to successfully connect to one of the addresses set in the parameter, as a network of Discovery Servers interconnected creates a redundancy that makes the network more robust, but it is not required to connect with all of the Servers in it.

The following command shows an example on how to connect with one Discovery Server in your own localhost listening in port 11811, one in the same local network in address 192.168.1.2:12000 and a third one in an external network in address 8.8.8.8:12345.

"127.0.0.1:11811;192.168.1.2:12000;8.8.8.8:12345"

In order to clarify how to set this parameter, please visit the Discovery Server CLI tutorial. The parameter of the Discovery Server Init New Monitor button in this application will be used equally as the input to the CLI command.

Warning

Due to the designed architecture for the communication of the Monitor application and the DDS entities, it is highly recommended not to initialize a Discovery Server Monitor with servers in different Discovery Server Networks (do not connect a monitor to servers that are not connected).

Warning

Do not initialize a Discovery Server monitoring in a Discovery Server Network where another Discovery Server is already been monitored. This will lead to an undefined behavior.

Example of usage¶

This example will show how to monitoring a DDS network using Fast DDS Monitor and how to understand the different application features and configurations.

Fast DDS with Statistics module¶

In order to show the Fast DDS Monitor running and monitoring a real DDS network, this tutorial uses a Fast DDS example to create a simple and understandable DDS network. The example proposed by this tutorial is using DDSHelloWorldExample of Fast DDS repository. Be aware that the statistics module is not compiled and used by default by Fast DDS but it has to be specifically configured to send statistical data of an specific entity.

In order to execute this minimum DDS scenario where each entity publish its statistical data, follow these steps:

Compile Fast DDS library with CMake option FASTDDS_STATISTICS to activate the statistics module (-DFASTDDS_STATISTICS=ON).
Compile Fast DDS library with CMake option COMPILE_EXAMPLES to build the examples (-DCOMPILE_EXAMPLES=ON).
Have Fast DDS Monitor installed or a working environment with Fast DDS, Fast DDS Statistics Backend and Fast DDS Monitor built.
Use the environment variable FASTDDS_STATISTICS to activate the statistics writers in the DDS execution (see following section).

For further information about the Statistics configuration, please refer to Fast DDS statistics module. For further information about installation of the Monitor and its dependencies, please refer to the documentation section Fast DDS Monitor on Linux or Linux installation from sources.

Hello World Example¶

For this tutorial it has being used the Fast DDS DDSHelloWorldExample to show a minimum DDS network being monitoring. Below are the commands executed in order to run this network. Nevertheless, this tutorial does not start with this DDS network running but it is executed once the monitor has been started. This does not change the Monitor behavior, but would change the data and information shown by the application.

Execute a Fast DDS DDSHelloWorldExample subscriber with statistics data active.

export FASTDDS_STATISTICS="HISTORY_LATENCY_TOPIC;NETWORK_LATENCY_TOPIC;PUBLICATION_THROUGHPUT_TOPIC;\
SUBSCRIPTION_THROUGHPUT_TOPIC;RTPS_SENT_TOPIC;RTPS_LOST_TOPIC;\
HEARTBEAT_COUNT_TOPIC;ACKNACK_COUNT_TOPIC;NACKFRAG_COUNT_TOPIC;\
GAP_COUNT_TOPIC;DATA_COUNT_TOPIC;RESENT_DATAS_TOPIC;SAMPLE_DATAS_TOPIC;\
PDP_PACKETS_TOPIC;EDP_PACKETS_TOPIC;DISCOVERY_TOPIC;PHYSICAL_DATA_TOPIC"

./build/fastrtps/examples/C++/DDS/HelloWorldExample/DDSHelloWorldExample subscriber

where subscriber argument creates a DomainParticipant with a DataReader in the topic HelloWorldTopic in Domain 0.

Execute a Fast DDS DDSHelloWorldExample publisher with statistics data active.

export FASTDDS_STATISTICS="HISTORY_LATENCY_TOPIC;NETWORK_LATENCY_TOPIC;PUBLICATION_THROUGHPUT_TOPIC;\
SUBSCRIPTION_THROUGHPUT_TOPIC;RTPS_SENT_TOPIC;RTPS_LOST_TOPIC;\
HEARTBEAT_COUNT_TOPIC;ACKNACK_COUNT_TOPIC;NACKFRAG_COUNT_TOPIC;\
GAP_COUNT_TOPIC;DATA_COUNT_TOPIC;RESENT_DATAS_TOPIC;SAMPLE_DATAS_TOPIC;\
PDP_PACKETS_TOPIC;EDP_PACKETS_TOPIC;DISCOVERY_TOPIC;PHYSICAL_DATA_TOPIC"

./build/fastrtps/examples/C++/DDS/HelloWorldExample/DDSHelloWorldExample publisher 0 500

where publisher argument creates a DomainParticipant with a DataWriter in the topic HelloWorldTopic in Domain 0. The following arguments indicate this process to run until the user press enter (0 samples) and to write a message every half second (500 milliseconds period).

Statistics topics¶

The environment variable FASTDDS_STATISTICS activates the statistics writers for a Fast DDS application execution. This means that the DomainParticipants created within this variable will report the statistical data related to them and their sub-entities.

For this example, only some of the available topics has been activated. This means that each participant will only report this specific data and it will not store or send any other data. This is very useful in order to limit the network traffic, as sending all the data highly increase the amount of DDS data sent.

The topics that are going to be reported by this example are:

HISTORY_LATENCY_TOPIC: Reports the latency of the messages between the two entities.
NETWORK_LATENCY_TOPIC: Reports the network latency of the messages between the two entities.
PUBLICATION_THROUGHPUT_TOPIC: Reports the publication throughput of the user’s DataWriters.
SUBSCRIPTION_THROUGHPUT_TOPIC: Reports the subscription throughput of the user’s DataReaders.
RTPS_SENT_TOPIC: Reports the number of RTPS packets and bytes being sent by each DDS entity.
RTPS_LOST_TOPIC: Reports the number of RTPS packets and bytes that are being lost in the transport layer (dropped somewhere in between) in the communication between each DDS entity and locator.
HEARTBEAT_COUNT_TOPIC: Reports the number of heartbeat messages sent by each user’s DataWriter.
ACKNACK_COUNT_TOPIC: Reports the number of ACKNACK messages sent by each user’s DataReader.
NACKFRAG_COUNT_TOPIC: Reports the number of NACKFRAG messages sent by each user’s DataReader.
GAP_COUNT_TOPIC: Reports the number of gap messages sent by each user’s DataWriter.
DATA_COUNT_TOPIC: the total number of user’s data messages and data fragments (in case that the message size is large enough to require RTPS fragmentation) that have been sent by each user’s DataWriter.
RESENT_DATAS_TOPIC: Reports the total number of user’s data messages and data fragments (in case that the message size is large enough to require RTPS fragmentation) that have been necessary to resend by each user’s DataWriter.
SAMPLE_DATAS_TOPIC: the number of user’s data messages (or data fragments in case that the message size is large enough to require RTPS fragmentation) that have been sent by the user’s DataWriter to completely deliver a single sample.
PDP_PACKETS_TOPIC: Reports the number of PDP discovery traffic RTPS packets transmitted by each DDS DomainParticipant.
EDP_PACKETS_TOPIC: Reports the number of EDP discovery traffic RTPS packets transmitted by each DDS DomainParticipant.
DISCOVERY_TOPIC: Reports the time when each local DomainParticipant discovers any remote DDS entity.
PHYSICAL_DATA_TOPIC: Reports the physical data of the participant. This will make possible to see in which hosts and context each entity is running.

Please refer to Fast DDS documentation for further information about these topics.

Fast DDS Monitor Execution¶

In the following section is presented a full Fast DDS Monitor execution monitoring a real DDS network.

Initial Window¶

The Monitor starts with non DDS entities running. First of all, the Fast DDS Monitor initial window is shown. Press Start monitoring! in order to enter the application and start the monitoring.

Initiate monitoring¶

Once in the application, the first Dialog that appear ask the user to insert a domain in order to start monitoring that domain. Monitoring a domain means to listen in that domain for DDS entities that are running and reporting statistical data. Please refer to section Monitor Domain for further information.

First, the Cancel button is pressed so the user can see around the monitor and check its configurations, but no entities or data will be shown as there are not domains being monitored. You can always return to the Initialize Monitoring dialog from Edit or Shortcuts Bar.

Let’s initialize monitoring in domain 0 and pressing OK.

Add physical and logical panels¶

By default, the Monitor only displays the DDS panel which lists the DDS entities together with their configuration and available statistics information. In order to open the logical and the physical panels, click on the top right corner of the Explorer panel, in button ··· and add all the panels to visualize the whole information.

At this point, you are going to see the whole window of the application. You should be able to see how an unique entity is present in the application in the left sidebar. This is the domain that you have just initiated. Once a domain is initiated, it is set as Selected Entity and so its information is shown in the Monitor Status Panel.

For specific details on how the information is divided and where to find it, please refer to User Manual.

Execute subscriber¶

Now, execute the first DDS entity in our DDS network: a DomainParticipant with one DataReader in topic HelloWorldTopic in domain 0 following the steps given in Hello World Example. Once the subscriber is running our window will update and you could see new information in the left sidebar.

First of all, the number of entities discovered has increased. Now, you have a DomainParticipant called Participant_sub, that holds a DataReader called DataReader_HelloWorldTopic_0.0.1.4. This DataReader has a locator, which will be the Shared Memory Transport locator. That is because the Monitor and the DomainParticipant are running in the same host, and so they communicate using the Shared Memory Transport (SHM) protocol.

You should be able to see as well that now Host exists, with a User and a Process where Participant_sub is running. This information is retrieved by the DomainParticipant thanks to activate the PHYSICAL_DATA_TOPIC. There is also a new Topic HelloWorldTopic under Domain 0.

Making double click in any entity name we could see its specific information, such as name, backend id, QoS, etc.

Execute publisher¶

The next step is to execute a publisher in topic HelloWorldTopic in domain 0, following the steps given in Hello World Example. Once the publisher is running you will see that new entities has appeared. Specifically, a new DomainParticipant Participant_pub with a DataWrtier DataWriter_HelloWorldTopic_0.0.1.3 and, in the case that this publisher has been executed from same Host and User, there will be a new Process that represents the process where this new Participant_pub is running.

Discovery Callbacks¶

Whenever a new entity is discovered by the Monitor there is an event registered in Log Panel. Checking this panel you could see the time when every entity that is being monitoring has been discovered. This panel is refreshed automatically whenever a new entity is discovered. Using the Refresh this information is cleared until the current moment.

Summary of Statistical Data¶

In Statistics Panel you can see the main information retrieved by each entity. This panel shows a summary of the data retrieved by the entity that is clicked. In this case, you could only see those data that the entities are publishing, and so the rest of the DataKinds that are related with the topics that we are not using will remain without data.

Change entity alias¶

In order to make the user experience easier, there is a possibility to change the name of an specific entity. We are going to change the name of our Host to make it easier to identify. For that, just do right-click over the entity name and menu with the available options for that entity will popup. Click on Change alias to re-name the entity.

Set the new alias that you want for this entity. From now on this name will be used all along the monitor.

Note

Be aware that this changes the alias of the entity inside the monitor, and does not affect to the real DDS network.

Create Historic Series Chart¶

This section describes how to graphically represent data reported by a DDS network.

Data Count Plot¶

This section explains how to represent the data being monitored and retrieved by the DDS entities. First of all, go to Edit->Display Historical Data. This will open a Dialog where you should choose one of the topics in which you want to see the data collected. The DATA_COUNT has been chosen for this tutorial.

Once done this, a new Dialog will open asking you to configure the series that is going to be displayed. In the case of DATA_COUNT, the data belongs to the DataWriter, and so you should choose this entity in the Source Entity Id: checkbox. The Number of bins is the number of points in which our data is going to be stored. In our case, we are going to use 20 bins. Selecting the Default initial timestamp as the Start time, the initial timestamp shall be the time at which the monitor was executed. Using Now in option End time will get all the data available until the moment the chart is created. Now for the Statistics kind option, we are going to use SUM as we want to know the number of data sent in each time interval.

Clicking Apply the series will be created in the main window, but the Dialog will no close. This is very useful in order to create a new series similar to the one already created. Here we are going to reuse all the information but we are going to change the Number of bins to 0. Using the value 0 means that we want to see all the different datapoints that the writer has stored. Be aware that option Statistics kind do not have effect when Number of bins is 0. Then, click OK and now you should be able to see both series represented in the DATA_COUNT window.

In this new chart created, you could see in the blue series the total amount of data packages sent in each time interval. Each points means that from that timestamp until the timestamp of next point the publisher sent 10/11 messages. The green series reports that this data has been sent periodically by the publisher each time it had updated the number of data sent by 1.

Latency Plot¶

Next, you are going to see how to represent the latency between these DomainParticipants. First, go to File->Display Historical Data. This will open a Dialog where you should choose one of the topics in which you want to see the data collected. For this case, we will choose FASTDDS_LATENCY. This data is called like this because it represents the time elapsed between the user call write function and the reader in the other endpoint receives it in the user callback. For the network latency there is other topic named NETWORK_LATENCY. However our endpoints are not storing neither publishing this type of data, and so it can not be monitored.

Once done this, a new Dialog will open asking to configure the series that is going to be displayed. In the case of FASTDDS_LATENCY the data to show is related with two entities. In our example we are going choose both DomainParticipants, and this will give us all the latency between the DataWriters of the first participant and the DataReaders of the second one.

For simplicity, we will use the same bins, start time, and end time configuration parameters as in the previous example.

Now for the Statistics kind option, we are going to use some of them in order to see more than one series of statistical data. Change the Statistics kind and click Apply for each of them in order to create a series for each one. The statistic kinds that we are going to use for this example are:

MEDIAN (blue series)
MAX (green series)
MIN (yellow series)
STANDARD_DEVIATION (purple series)

It is worth mentioning that the series name, its color, the axis, and some features of the chart box could be changed as mention in Chartbox.

Create Dynamic Series Chart¶

This section describes how to graphically represent data in real-time of a running DDS network.

Periodic Latency Plot¶

This section explains how to represent the FastDDS latency in real-time between the publisher and the subscriber. First of all, click in . This will open a Dialog where you should choose one of the topics in which you want to see the data collected. For this case, choose FASTDDS_LATENCY. Set a Time window of 1 minute. This means you will be able to see the data of the last minute of the network. Finally, set an Update period of 5 seconds. This will query for new data every 5 seconds and retrieve and display it in the chart.

After this, a new Dialog will open asking to configure the series that is going to be displayed. In the case of FASTDDS_LATENCY the data to show is related with two entities. In our example we are going choose our Host. This will retrieve the latency measured in the communication between the entities of this host to itself. For this case, it is going to be the latency between the two participants, but this trick is very useful when you want to filter latency between two specific hosts or even to collect all the latency in the same domain.

Now for the Statistics kind option, we are going to use some of them in order to see more than one series of statistical data. Change the Statistics kind and click Apply for each of them in order to create a series for each one. The statistic kinds that we are going to use for this example are:

MEAN (blue series)
MAX (green series)
MIN (yellow series)

_images/dynamic_latency_configuration.png

This chart will be updated each 5 seconds, displaying the data collected by the monitor within the last 5 seconds. The axis are updated periodically, and so the zoom and chart move is not available in this kind of charts while running. For this propose, the play/pause button stops the axis to update, and so you could zoom and move along the chart. Be aware that pausing the chart do not stop new points to appear, as every 5 seconds the update of the data will still happen.

Latency DataPoints¶

There is a special feature for real-time data display that allow to see every DataPoint received from the DDS entities monitored (similar to bins 0 in historic series). In order to see this data in real-time, add a new series in this same chartbox in Series->Add series. Choose again the Host as source and target and choose NONE as Statistics kind.

Now you should be able to see a new series (by default purple, in the example image red) that represents each of the DataPoints sent by the DDS entities and collected by the monitor in the last 5 seconds. This is very helpful to understand the Statistics kind. As you can see, the MEAN, MAX and MIN in each interval are calculated with this DataPoints.

Note

The monitor retrieves each DataPoint with the time of the beginning of the interval it represents. This means that the real DataPoints used to calculate the MEAN, MAX and MIN are the ones ahead of it.

It is worth mentioning that dynamic series could be configurable as the historic series. The label and color of each series is mutable, and the chart could zoom in and out and move along the axis while the chart is paused.

Initialize Monitoring¶

When the eProsima Fast DDS Monitor application is launched, the following screen is displayed. Click on the “Start monitoring!” button to start monitoring a Fast DDS application.

Next, it is possible to select the type of monitoring to be performed, as explained in Section Monitor Domain. The screenshot below shows the whole monitor interface and the dialog box that the user must fill in to start monitoring a DDS Domain or a Discovery Server network.

Layout¶

This section explains the Graphical User Interface (GUI) of the Fast DDS Monitor application. It will briefly explain the main menus and windows that could be seen, in order to familiarize the user with where to find the buttons and information. Below is a screenshot of the Fast DDS Monitor application in operation.

Shortcuts Bar¶

This horizontal bar contains shortcuts to the main operations supported by the application, so the user has a faster access to the main functionalities. This bar could be configured in the View tab of the application menu.

For the explanation of how to configure this bar refer to the section Shortcuts Bar.

Explorer Panel¶

In this panel it will be shown the different entities that has been discovered by the monitor. They will be displayed in interactive lists that the user could expand or collapse. These entities are clickable as well, in order to inspect their information shown in this same panel

This panel contains a mutable number of subpanels. The different panels that could be shown are the DDS Panel, the Physical Panel, the Logical Panel and the Monitor Status Panel. In these subpanels, the entities discovered are going to be displayed depending on their kind. In order to know which kind of entities the application has and how are they divided in categories, please refer to Entities.

To add a new panel to display other relevant information, use the ... button in the upper bar of the panel and select those subpanels that want to be show or hide. To increase or decrease this sidebar size, grab the border of it and move it to the desired size. In order to hide the whole left sidebar, click in the < button in the upper panel or click Hide Left sidebar in the View menu..

For more information about what is an entity and how they are organized refer to Entities. For more information about what means to select an entity refer to Selected Entity.

DDS Panel¶

This subpanel shows the DDS Entities of the monitor. This entities are the DDS DomainParticipant, the DDS DataReader and DataWriter, and the transport Locators that each entity is using. This subpanel will be filled with the DDS entities that are related with the entity currently selected, so it could happen that not all the DDS entities discovered by the monitor appears in this subpanel at a certain point (see Selected Entity for further details).

For the explanation of this entities and the interaction with them refer to the section DDS Panel.

Physical Panel¶

In this subpanel it will appear the Entities discovered by the monitor that refers to physical entities. There are three different kind of physical entities, Host, User and Process. These entities refer to the main information of the machine and the context where an application using Fast DDS is running. For further explanation of this entities and the interaction with them refer to the section Physical Panel.

Logical Panel¶

In this subpanel it will appear the Entities discovered by the monitor that refers to abstract entities in a DDS communication network. These entities are Domain and Topic. These entities refer to abstract partitions in a DDS network. Only entities in the same Domain could communicate to each other by publishing or subscribing in the same Topic. For further explanation of this entities and the interaction with them refer to the section Logical Panel.

Monitor Status Panel¶

This subpanel displays information regarding the last entity clicked. This information is divided in two categories and are shown in the different subpanel tabs. First, the info tab contains the general information of the last entity clicked. Secondly, the Statistics tab contains a summary of the main statistical data regarding the last entity clicked.

Info Panel¶

This panel shows the main information of the last entity clicked. This information differs depending on the kind of the entity, i.e. for a DDS Entity, the QoS information would be shown, while for a Process, its process id will be displayed.

For the explanation of this information refer to the section Info Panel.

Statistics Panel¶

This panel shows a summary of the main statistic data related with the last entity clicked.

For the explanation of this information refer to the section Statistics Panel.

Monitor Status Panel¶

In this side bar it will be shown different data related with the entities that are being monitored or related with the actual state of the application. This side bar is divided in two different side bars. The upper one contains Monitor Status Panel and Statistics Panel. To change from one another press on the name of the tab an choose the panel desired to be displayed. The lower side bar contains Monitor Status Panel, Log Panel and Issues Panel. To change from one to another press on the name of the tab an choose the panel desired to be displayed.

To increase or decrease this sidebar size, grab the border of it and move it to the desired size. In order to hide the whole left sidebar, click in the < button in the upper panel or click Hide Left sidebar in the View menu.

Status Panel¶

This panel shows a collection of data related with the actual state of the application:

Entities refer to the number of entities being monitored in the user application.
Domains is a collection of the Domains that has been initialized in the Monitor.

For the explanation of this information refer to the section Status Panel.

Log Panel¶

This panel shows the callbacks that the application has obtained. These callbacks refer to different events in the DDS network that is being monitored. These callbacks could be cleared by using the Refresh. A callback may refer to:

The discovery of a new Entity in the DDS network.
The reception of new data related to any of the entities that are being monitored.

For the explanation of this information refer to the section Log SubPanel.

Issues Panel¶

This panel lists the error events of the application. The events that the application reacts to in the current version are:

Attempt to start monitoring a DDS Domain or a Discovery Server network that has been previously initialized.

For the explanation of this information refer to the section Log SubPanel.

Main Panel¶

The central window it will display the data charts, so-called Chartbox, that the user has configured. To create a new Chartbox go to Edit->DisplayNewData in the application menu. This button will create a new Chartbox where new series could be added, removed or modified.

For further information about how to create a chart refer to the section Charts Panel.

Chartbox¶

These windows in the central panel store some series or data configurations to show a specific data type for one or several entities in a specified time interval and with different accumulative operations on the data.

These Chartbox could be moved along the main window. In order to move one of this charts, press in the Chartbox title and grab the object to its new location inside the main panel. The rest of the Chartboxes will automatically rearrange when one of them is moved to a different position.

Create Series Dialog¶

This Dialog will appear every time a new Chartbox is created, or adding a new series by the button in the Chartbox Series->AddSeries.

Create historical series dialog¶

Create real-time series dialog¶

For further details on how to configure a new series refer to Historic Data for historic data or Real-Time Data for dynamic data.

Application Menu¶

This section describes the operations that can be performed in Fast DDS Monitor through the application menu.

File¶

Initialize Monitor¶

Button to start monitoring a new DDS network. The entities of this network will be automatically discovered. Moreover, their connections, their configuration and statistical data reported by them will be built and displayed on the monitor for further user queries.

Section Monitor Domain contains all the definitions and explanation about what monitor a domain means in the context of the application.

Pressing this button, a new Dialog with two tabs will be displayed. Each tab allows to start a monitor in a DDS network deployed using the Simple Discovery Protocol (SDP) or the Fast DDS Discovery Server (DS).

Warning

Starting a monitor in a domain or Discovery Server already initialize will duplicate the entities in them and may lead to an undefined behavior.

Simple Discovery¶

This dialog requests the user to introduce a number between 0 and 200 which will be the DDS Domain number. This will start a monitor in a specific DDS domain. The entities in this domain will be automatically discovered.

Discovery Server¶

This dialog requests the user to introduce a list of network addresses in a specific string format to connect with one or more Fast DDS Discovery Servers. This string must contain the IP-port pair where the Discovery Server is listening in the format ip:port separated by ;.

This will connect the Fast DDS Monitor to the Discovery Servers listening on the addresses set, and it will get all the discovery information of the entities connecting through them.

Export to CSV¶

Export all the data displayed in the current Fast DDS Monitor session to a CSV file. Please refer to section Export data for more information on the format of the generated CSV file.

Dump¶

Dump the information from the database to a JSON file. Please refer to section Export data for more information on the format of the generated JSON file.

Dump and clear¶

Same as the previous one but clearing the statistics data of all the entities.

Quit¶

Close the application.

Edit¶

Display Historical Data¶

Create a new historic Chartbox in the central panel. To know how to configure a historic Chartbox, please refer to the section Historic Data.

Display Dynamic Data¶

Create a new dynamic Chartbox in the central panel. To know how to configure a dynamic Chartbox, please refer to the section Real-Time Data.

Delete inactive entities¶

This button remove all the inactive entities from the database.

Delete statistics data¶

This button clear the statistics data of all the entities.

Scheduler Configuration¶

Creates a schedule to dump the database to a file, remove old data and/or remove inactive entities at a specified interval.

Refresh¶

This button resets the entity clicked and the entities models in case there is some entity missing in the display.

Clear Log¶

This button clears the callbacks log.

Clear Issues¶

This button clears the issues log.

View¶

Hide/Show Inactive entities¶

The user of the application can decide whether to display the currently inactive entities. In case they are shown, it will be possible to access the data related to them, while if they are hidden from the monitor, they will no longer be available in the whole application framework. The latter means that it will not be possible to plot charts with data relating to these entities. This button hides/reveals the currently inactive entities detected by the monitor.

Hide/Show Metatraffic¶

Entities utilized for sharing metatraffic data are not shown by default. These include Fast-DDS Statistics module topics and the ones used by ROS for metatraffic data exchange, as well as the endpoints to which these topics are bound. Same as with the hide/show inactive entities feature, when metatraffic entities are hidden they are no longer available in the whole application framework. This button displays/hides the metatraffic entities detected by the monitor.

Dashboard Layout¶

Changes the size of the chart boxes displayed in the main panel of the application. Three mutually exclusive layout options are defined and explained below.

Large: A single full-screen chart is displayed.

Medium: Adjusts the chart size to show two chart boxes per row.

Small: Adjusts the chart size to show three chart boxes per row.

Help¶

Documentation¶

Link to this documentation.

About¶

General information of the currently running Fast DDS Monitor application.

Shortcuts Bar¶

This toolbar expose shortcuts to the buttons with the main functionality to interact with the Fast DDS Monitor application. This buttons functionality could be seen in Edit.

The meaning of each of the icons available in the shortcut bar is explained below:

- Change the main dashboard layout.

- Display historical data.

- Display real-time data.

- Refresh Fast DDS Monitor.

- Clear the list of logs.

- Clear the issues panel.

This bar can be hidden (or revealed in case it is already hidden) from the menu View->Hide/Show Shortcuts Toolbar. It is also possible to configure the shortcuts displayed from View->Customize Shortcuts Toolbar.

Explorer Panel¶

The left sidebar shows the various entities that the application has knowledge about and their available information. It is recommended to check the section Entities in order to get a better approach on the kind of entities that are displayed and the connection between them.

DDS Panel¶

In this panel are displayed all the DDS Entities that has been discovered by the monitor so far under every DDS domain or Discovery Server monitored. This panel displays specific DDS entities related with the Fast DDS Monitor entity currently selected (see Selected Entity). For example, it is possible to track the DDS entities created from an application running on a specific Host, User, or Process, as well as the DDS entities that are working on a specific DDS domain or are publishing or subscribed to a given topic. Every entity in this panel is interactive:

Clicking in the Participant name or the Participant icon will expand or collapse the list of DataWriters/DataReaders of that Participant.
Clicking in the DataReader/DataWriter name or the DataReader/DataWriter icon will expand or collapse the list of Locators of that DataReader/DataWriter.
Double clicking in an entity will set this entity as selected. Please refer to Selected Entity for more information on what it means for an entity to be selected.

Physical Panel¶

This panel displays all the Physical Entities that the monitor has discovered so far. Similar to the DDS Panel, every entity in this panel is interactive:

Clicking in the Host name or the Host icon will expand or collapse the list of Users of the Host.
Clicking in the User name or the User icon will expand or collapse the list of Processes of the User.
Double clicking in an entity will set this entity as selected. Please refer to Selected Entity for more information on what it means for an entity to be selected.

Logical Panel¶

This panel displays all the Logical Entities that are being monitored. he DDS domains that Fast DDS Monitor is monitoring are the ones set by the user (see Monitor Domain) and no new domains will or could be discovered apart from them since the Domains could not be discovered, but known beforehand. Therefore, this panel will only update the information. For example, having enabled the monitoring of Domain X, if an application using Fast DDS creates a new DomainParticipant in that domain with a DataWriter publishing in Topic Y, the information of that topic will appear in this view listed under Domain X to which the DomainParticipant discovered by the monitor belongs.

Similar to the DDS Panel, every entity in this panel is interactive:

Clicking in the Domain name or the Domain icon will expand or collapse the list of Topics of the Domain.
Double clicking in an entity will set this entity as selected. Please refer to Selected Entity for more information on what it means for an entity to be selected.

Info Panel¶

In this panel it is displayed the specific information of the entity that is currently selected (see Selected Entity). This information has some fields that are general for all the entity kinds, and some others that depends on the specific entity kind:

General fields
- name: internal name of the entity
- id: internal unique id for each entity
Process
- pid: Process Id in its host
Topic
- type_name: name of the data type of the topic
Participant
- GUID: DDS GUID
- QoS: DDS QoS information
DataWriter
- GUID: DDS GUID
- QoS: DDS QoS information
DataReader
- GUID: DDS GUID
- QoS: DDS QoS information

Statistics Panel¶

In this panel it is displayed a summary of some data types of the entity that is currently selected (see Selected Entity). Regarding the selected entity, the data will be fulfilled collecting all the data of all the entities related to the this one. The data is calculated by accumulating the data of this entity (using a specific StatisticKind in each case) in one bin from the first to the last data available. In case there is no selected entity, the information displayed is the group of all the entities that exist in the application. The data displayed is the following:

Data Kind	Statistic kind	Description
NETWORK_LATENCY	MEDIAN	Median value of Network Latency
NETWORK_LATENCY	STANDARD_DEVIATION	Standard deviation of Network Latency
FASTDDS_LATENCY	MEDIAN	Median value of Application Latency
FASTDDS_LATENCY	STANDARD_DEVIATION	Standard deviation value of Application Latency
PUBLICATION_THROUGHPUT	MEDIAN	Median value of Publication Throughput
PUBLICATION_THROUGHPUT	STANDARD_DEVIATION	Standard deviation value of Publication Throughput
SUBSCRIPTION_THROUGHPUT	MEDIAN	Median value of Subscription Throughput
SUBSCRIPTION_THROUGHPUT	STANDARD_DEVIATION	Standard deviation value of Subscription Throughput
RTPS_BYTES_SENT	MEDIAN	Median value of Total Bytes sent in RTPS packages
RTPS_BYTES_LOST	MEDIAN	Median value of Total Bytes lost in RTPS packages
RESENT_DATA	MEAN	Mean value of Data packages that had to be resent
HEARTBEAT_COUNT	SUM	Total number of Heartbeat messages
ACKNACK_COUNT	SUM	Total number of Acknack messages
NACKFRAG_COUNT	SUM	Total number of Nackfrag messages
GAP_COUNT	SUM	Total number of Gap messages
DATA_COUNT	SUM	Total number of Data messages
PDP_PACKETS	SUM	Total number of PDP packets sent
EDP_PACKETS	SUM	Total number of EDP packets sent

Status Panel¶

The left sidebar’s status panel shows settings about the entities monitored by the application and some general information about the state and the events of the monitor.

Status SubPanel¶

In this panel it is displayed a brief information of the actual state of the Fast DDS Monitor,

Entities
- Domains: A list of the Domains that has been initialized in the Monitor so far.
- Entities: Total number of entities that are being tracked.

Log SubPanel¶

This panel displays the events that the application has received. These events arise as callbacks that are generated because of new entities has arrived to the network or has been discovered, or because it has been any change in the DDS network state. Each callback contains the entities discovered by the Monitor and the time it has happened. This list could be erased using Refresh.

Issues Panel¶

This panel lists the error events of the application. The events that the application reacts to in the current version are:

Attempt to start monitoring a DDS Domain or a Discovery Server network that has been previously initialized.

Note

Issues section is in progress and will display more information soon.

Main Panel¶

In the central panel or chart panel, is where the data of the entities will be displayed. The main feature of the Fast DDS Monitor application is to graphically display the data that is being monitored. DDS entities have associated different types of data (so-called DataKind) that could be visualize by configuring a chart. For example, it can be displayed the mean, median and standard deviation latency between two machines (Hosts) running Fast DDS applications for the period of two hours in intervals of ten minutes.

Charts Panel¶

In this panel will be displayed the different chartbox with the different series the user creates.

Chart series¶

A DataPoint in a chart series in the Fast DDS Monitor refers to a specific data type of the DDS network monitoring. Each DataPoint consists in a timestamp and a real value. The timestamp is the moment the data has been created, reported, received, etc. depending on the DataKind. The value refers to the real value of this DataPoint for this DataKind at the moment of the timestamp value.

For example, each DataPoint of the DataKind DATA_COUNT has a timestamp and an integer value. This value is the number of Data packets a DataWriter sent since the last time that same data was reported.

Chart view¶

Every DataKind is represented similarly inside a Chartbox. None, one or multiple lines of different colors will represent the different data series that are being displayed in the chart with the following format:

The X axis is the time value of the data.
The Y axis is the value that is store in the data.

This could be integers, doubles or times, but for the same DataKind will always be the same value type. Every point represents an accumulated value of DataPoints of a data kind in a time range.

Chartbox kinds¶

There are two kinds of Chartbox that could be created, historic and dynamic.

The historic chartbox represents static data that has been accumulated along the monitor execution. This data is not updated with new data or refreshed in case somethings has changed. See the details of this chartbox kind in section Historic Data.
The dynamic or real-time chartbox represents the new data that is being collected in real time by the monitor. These series will update over time with the new data received from a DDS network, and so the new data will be displayed in pseudo-real-time. See the details of this chartbox kind in section Real-Time Data.

Common Series parameters¶

Some of the parameters of the chartbox creations remains on the kind of chartbox to create. The ones mentioned here are the common parameters used by the two kinds of chartbox.

Data kind¶

The DataKind refers to the data that this chartbox will refer to. There are several DataKinds that represent each of the data kinds that a Fast DDS network can report. (Be aware that by default a DDS network will not report most of this data, and in case of Fast DDS it must be configured beforehand in order to report it periodically).

Series label¶

Name the new series in the Chartbox. If not set, the default series name is formed according to the following rule: <cumulative_function>_<source_entity_kind>-<target_entity_id>_<target_entity_kind>-<target_entity_id>.

Source Entity Id¶

This is the name and entity Id of the entity from which the data will be collected in the format <name>:\<<id>\>. This field has an entity kind to encapsulate the ids of the entities with the same kind, and make it easier for the user to search for the id required.

Each DataKind is related with one entity kind, normally a DataWriter or a DataReader, which are the producers of that DataKind. However, every entity kind is available to choose the data to represent. When an entity without this type of data is selected, the monitor will look for the entities contained in the specified entity that do report this specific DataKind. For example, in case the user wants to represent the number of packets (DATA_COUNT) transmitted by a Host, the monitor will look for all the DataWriters contained in that Host and report the total number of packets.

Continuing with the DATA_COUNT DataKind example, the monitor will find every DataWriter in this Host by finding every User in this Host, then finding every Process in these Users, finding every DomainParticipant in these Processes and finding every DataWriter in these DomainParticipants. Hence, the data displayed will be all the data that all those DataWriters have stored, accumulated by the cumulative function. Please refer to Entities section for more information on the monitor entities connections.

It is recommended to check some examples (see Example of usage) in order to better understand this functionality.

Target Entity Id¶

Note

Not every DataKind has a target entity, so the dialog will only show this field when the DataKind selected requires it.

This is the entity Id of the entity to which the data refers. This field works similar to the Source Entity Id. Some DataKind has a target entity to which the data refers, and this target must be of an specific entity kind. Choosing an entity of a different kind than the one this data requires will be solved by using the same mechanism explained in Source Entity Id. That is, searching for the correct entity kind by following the connections between entities.

i.e. To show the DataKind FASTDDS_LATENCY, that is reported by a DataWriter, and targeted to a DataReader, from an entity Host_1 to an entity Host_2, both of kind Host, the data displayed would be collected following the steps described below:

Get all the DataWriters of Host_1 by searching for its Users, their Processes, their DomainParticipants and their respective DataWriters.
Get all the DataReaders of Host_2 by searching for its Users, their Processes, their DomainParticipants and their respective DataReaders.
Get all the data from the DataWriters found that refer to the DataReaders found inside the interval set.
Accumulate the data using the cumulative function.

It is recommended to check some examples (Example of usage) in order to better understand this functionality.

Statistics kind¶

The cumulative function is used to accumulate the data points that fulfilled the conditions set in this configuration. When there are several data points to show in a single time frame these data points are transformed into one by a cumulative function. This function is the one set in Statistics kind.

The available methods to accumulate some data points into one are:

NONE: returns the DataPoint with the lower time.
MEAN: calculate the mean value of all the data points.
STANDARD_DEVIATION: calculate the standard deviation of all the data points.
MAX: returns the DataPoint with the maximum value.
MIN: returns the DataPoint with the minimum value.
MEDIAN: calculate the median of all the data points.
COUNT: returns the number of DataPoint in this time frame.
SUM: calculate the sum of all the data points.

In case the Number of bins is 0 the Statistics kind is not used as the data is not going to be accumulated.

Historic Data¶

Create Historic Series Chartbox¶

An static chartbox could only contain series referring the same DataKind. In order to create a new chartbox in the central panel, use the button Display Historical Data in the Edit or in Shortcuts Bar.

Data Kind¶

Check common parameters explanation Data kind.

Clicking OK will create a new chartbox referring the DataKind chosen that will hold historic series.

Create Historic Series Dialog¶

The Dialog (Create Series Dialog) allows to create a new data series in a Chartbox. The fields in the dialog configure the data that will be displayed When all the data has been set in the Create Historic Series Dialog, press Apply to create the series and continue with the same parameters set in order to create a new series. Pressing OK the actual parameters are used to create a new series unless it has not been any changed since Apply has been pressed. Press Cancel close the window without creating any series.

Series label¶

Check common parameters explanation Series label.

Source Entity Id¶

Check common parameters explanation Source Entity Id.

Target Entity Id¶

Check common parameters explanation Target Entity Id.

Number of bins¶

Number of DataPoints that will be displayed for this chart series. The data is collected in individual points in every entity, without a regular time interval or pattern. Therefore, to show the data in a better understandable manner, each of these points will be merged in a single point inside a fraction of the time interval. The Number of bins determines how many fractions on which this time interval will be split, and thus, how many points will be displayed in the chart. To see all the individual data points without accumulate them, set the Number of bins to 0.

Warning

Some of the data queried could not exist. In these cases the point will not be plotted, and the number of points in the series will not match with the number of bins.

Start time¶

The time that represents the minimum limit for the data points that will be displayed. That is, every data that refers to a time before this value will not be displayed. Default initial timestamp means the time when the monitor has been initialized.

End time¶

The time that represents the maximum limit for the data points that will be displayed. That is, every data that refers to a time after this value will not be displayed. Now means the current time. Be aware that the current time is not the maximum time that could be set up to see the data, but setting a time bigger than Now could (obviously) not have data points in the higher time frames.

Statistics kind¶

Check common parameters explanation Statistics kind.

Quick explanation of the data displayed¶

First, the application will create a complete list of data points by merging the data of all entities referred to in this query. (see the example in Source Entity Id).

The current represented chart consists in a number of frames or bins, set by the Number of bins variable from the value Start time to the value End time. Inside one of this fractions of time, referred to as frames, there could be none, one or several data points. If there are no data points in this frame, the value will be 0 or will not be displayed in the chart. If there are data points in the frame, only one point will be displayed in the chart for this time frame. This point will be calculated by accumulating all these points inside the frame by a cumulative funcion, specified by the value Statistics kind.

In case the Number of bins is set to 0, there is no accumulation or time frame, and so the data displayed will be all the data points for this configuration, each in its time value.

Warning

Some of the data queried could not exist in the database for many reasons, i.e. the entity did not exist in the time where the query requires data, the entity does not report such data, or simply some data is reported with lower frequency than the one asked. In these cases, the graph could not be connected and the points where the data is not retrieved will not be shown.

Real-Time Data¶

A Dynamic or Real-Time series displays the data that is being receiving by the monitor in the current moment. This is a pseudo-real-time display of a running DDS network. Pseudo because it is not an exact representation of the DDS network activity in the exact moment it is represented, but it represents a periodical update of the last seconds of the network.

Every data displayed is delayed by 5 seconds in order to accurately represent all the data reported by the network. This is because the data is not instantly reported by Fast DDS, an thus it could be that the data used to update the chart is not complete.

Create Dynamic Series Chartbox¶

An static chartbox could only contain series referring the same DataKind. In order to create a new chartbox in the central panel, use the button Display Dynamic Data in the Edit or in Shortcuts Bar.

A new dialog will appear asking to choose some parameters that will be share for all the new series created in this new chartbox.

Data Kind¶

Check common parameters explanation Data kind.

Time window¶

This parameter is the default size and value of the X axis. The X axis will be set by default to have the current moment to the rightmost point. The X axis leftmost point will be the current time minus the size of the Time window.

Update period¶

This parameter refers to the time elapsed between two updates of the chartbox series. Each of the series inside the chartbox will be updated with the new data collected every Update period seconds.

Maximum data points¶

This parameter set the default for the maximum amount of data points that the series in this chartbox will have. Check series Maximum data points section for more information.

Clicking OK will create a new chartbox referring the DataKind chosen that will hold dynamic series.

Create Dynamic Series Dialog¶

This Dialog (Create Series Dialog) allows to create a new data series in a Chartbox. The fields in the dialog configure the data that will be displayed When all the data has been set in the Create Dynamic Series Chartbox, press Apply to create the series and continue with the same parameters set in order to create a new series. Pressing OK the actual parameters are used to create a new series unless it has not been any changed since Apply has been pressed. Press Cancel close the window without creating a new series with the current parameters.

Series label¶

Check common parameters explanation Series label.

Source Entity Id¶

Check common parameters explanation Source Entity Id.

Target Entity Id¶

Check common parameters explanation Target Entity Id.

Statistics kind¶

This parameter behaves as it is explained in Statistics kind except for NONE kind. Selecting NONE as Statistics kind will display every data available in the interval of time given by Update period with no accumulation.

Note

The data will not be displayed at the time it arrives in any case. It will always appear displayed after each Update period.

Maximum data points¶

This parameter limits the number of data points that will be showed for this specific series. Data points will be added dynamically to the series. This can, at some point, generate an efficiency problem due to memory exhaustion. In order to avoid this, this parameter will limit the number of data points, removing the old data as new ones are being added. Use value 0 for not limited series.

This value can be changed by series at any time in the series menu.

Cumulative data¶

This option allows the user to define the time interval for which the statistic selected in “Statistic kind” is to be calculated. That is, in case the user selects a time interval to obtain accumulated statistics data, the statistics will be applied to all the data collected by the monitor in that defined time interval. This allows the update interval of the chart and the time interval for calculating the statistics to be independent.

Let’s look into a simple example of monitoring the latency of a publisher and a subscriber in the Shapes Demo application launched with statistics enabled (a detailed example of Fast DDS Monitor monitoring a Shapes Demo application is shown in the following video tutorial). First, a chart is created to monitor the application latency with a time window of 5 minutes and an update period of 5 seconds. Then the dialog box for creating series in the graph is opened. Select your host as source and target entities and the DataWriters and DataReaders running on your machine will be automatically detected. Select the mean as the type of statistical measurement to be applied. Finally, create three series with three different types of accumulation:

No accumulation. The average latency between publisher and subscriber in the last update period, 5 seconds in this particular case, is calculated.
With accumulation from the first available data point. This calculates the average latency between publisher and subscriber from the time the monitor has the first available data until the current time. This current instant is updated every update period, adding new points to the calculated statistic.
With accumulation by setting a time interval. The average latency between publisher and subscriber is calculated from the current time minus the cumulative time interval set until the current time.

Below is an image of the three series created. It can be seen that the series with a longer accumulation period tends to have a steady latency value, being less susceptible to strong but momentary latency variations. On the contrary, the series that calculates the average latency with the available data of the last 5 seconds shows a large variation due to the smaller number of data points available for the calculation of the statistic.

Quick explanation of the data displayed¶

First, the application will create an empty chart where X axis represents the time between the current moment and that time minus the Time window size. This window is permanently moving in order to always represent the current time. This X axis movement could be paused in order to move and resize the chart at any moment, and new data will still appear.

Every Update period new data will be displayed in the right side of the chart. The new data displayed references the accumulative value of the data that has been stored in that amount of time.

Warning

Some of the data queried could not exist in the database for many reasons, i.e. the entity did not report anything in the time where the query requires data. In these cases, after an Update period there will not appear any point and the chart will be connected with the next interval with data.

Chartbox¶

In this section it is explained the main functionalities and interactions available within a Chartbox, a window contained in the Main Panel that displays entities data with different configurations.

To start a new Chartbox, press Display Historical Data or Display Dynamic Data in Edit or in Shortcuts Bar. These chartbox will be displayed in the central panel with the title of the DataKind they refer to. In these charts it will be displayed the Series of data that the user initialize. For how to set a new series please refer to Create Historic Series Dialog or Create Dynamic Series Chartbox.

Chart Menu¶

In the top bar of each Chartbox there is a Menu tab Chart with the following buttons.

Reset zoom¶

Reset the zoom of the Chartbox to the standard one. The standard zoom is calculated to fit all the data that is being currently displayed. It is also possible to take this action by clicking on the button displayed in the same chart box.

Set axes¶

This menu opens a dialog pop-up for the user to set the axes of the chart. Changing the X-axis (time axis) is disabled by default, thus maintaining the time values currently displayed on the chart. This allows dynamic charts to continue to update the value of the X-axis while the Y-axis remains fixed. It is also possible to access this dialog by clicking on the button displayed in the same chart box.

To return to the original time axis, and allow a dynamic update of the Y-axis, simply click on the Reset zoom button located to the right of the chart.

Clear chart¶

Eliminate every data configuration displayed in the Chartbox

Rename chart box¶

Change the name of the chart box.

Close chart box¶

Eliminate the Chartbox and every configuration in it. It could be removed as well pressing the x button in the top of the chart.

Export to CSV¶

Export the data of all series in the chart box to a CSV file. Please refer to section Export data for more information on the format of the generated CSV file.

Chart Controls¶

Displays an informative dialog with the key combination to execute actions on the chart. It is also possible to access this dialog by clicking on the button displayed in the same chart box.

Chart Interaction¶

The user could interact with the Chartbox and the data in it by resizing and moving the view.

Point description¶

Clicking in any point of a displayed series, an info box will be prompt with the x and y label values of the data point.

Moving the view¶

Press and hold Ctrl key and left click in one point of the Chartbox. Move the mouse to scroll over the data.

Zoom in/out¶

Press and hold Ctrl key and scroll up to zoom in to the center of the Chartbox. Press and hold Ctrl key and scroll down to zoom out from the center of the Chartbox.

Series Configuration¶

Right clicking in the name of a series in the Legend will open a dialog with the available configurations for a series.

Remove series¶

Remove this series.

Rename series¶

Change the name of this series.

Change color¶

A Dialog will open to choose a new color for the series and the points displayed. Also available with left click on the color of the series in the Legend.

Hide/Show series¶

Hide a series if it is displayed, or it reveal it if it is hide. Also available with left click on the name of the series in the Legend.

Export to CSV¶

Export the series data to a CSV file. Please refer to section Export data for more information on the format of the generated CSV file.

Dynamic chartbox¶

The chartbox that holds dynamic series have some extra functionality. These chartbox could be stopped at any time (or played in case they are already stopped). This allows to stop the updating the axis, so zoom and move along the chart is available. The data presented in the chartbox will keep updating with the same time interval independently of the play status.

To pause the real time update of the time axis, click on the Real-Time menu or on the / button placed on the right side of the chart, or set the axes to a specific value with the Set axes button.

Selected Entity¶

The application stores one entity as last entity clicked in order to manage what information is displayed. In the context of the Fast DDS Monitor, an entity is every element that can be tracked by the monitor (see Entities). To set one entity as clicked double click in any entity in any of the Explorer Panel panels, and this entity will be set as Selected Entity for the whole application from now on. Selecting an entity has the following effects in the application view:

The entity clicked will remain marked with blue background while no other entity is clicked or the Selected Entity is restore.
In the Monitor Status Panel, the information related to this entity is displayed, such as QoS or specific entity settings.
In the Statistics Panel, a general summary of the data stored for this entity is listed.
If the selected entity is a Fast DDS Monitor entity belonging to the Physical or Logical Entities group, the entities displayed in DDS Panel are only those related to this entity. Therefore, clicking one of the DDS Entities do not update the DDS Panel. To check the relation between please refer to Entities section.

Deselect Entity¶

To change the actual Selected Entity just click in a another entity in the Explorer Panel. Moreover, it is possible to deselect any entity. Use the Refresh button (Refresh) in order to preform that action. Not having any entity selected has the following effects in the application view:

The DDS Panel will list all DDS entities present in any Domain monitored by Fast DDS Monitor, i.e. it will be possible to view any DomainParticipant, DataWriter and DataReader regardless of the physical entity or the DDS logical entity under which they are located.
The information shown in the Monitor Status Panel is a brief summary of the current state of the application.

Export data¶

One of the main functionalities of the Fast DDS Monitor is the possibility of exporting the data generated in each monitoring session. The different monitor capabilities for exporting user data are explained below.

Export charts in a CSV file¶

The monitor offers the possibility to export to a CSV file all the data that have been or are being represented in each of the charts boxes, both historical and real-time charts.

Thus the monitor offers the user three possibilities:

Export the data of a single series. This can be done from the series menu explained in section Chart Menu.

Export the data of all the series belonging to a chart box. This can be done from the Chart menu available in each chart box. This menu is explained in section Series Configuration.

Export all the data of all the series of all the chart boxes. This is done from the application File menu, explained in section File.

Format of the CSV file¶

This section presents a table with the format of the CSV file containing the exported data.

	<DataKind>
	<Chart box name>
ms	<DataKind units>
UnixTime	<Series name>
<unix_time>	<data_value>

Export database in a JSON file¶

The monitor gives you the option to dump the data from the database to a JSON file.

Thus the monitor provides the user two options:

Dump. Explained in section Dump.

Dump and clear. Explained in section Dump and clear.

Format of the JSON file¶

This section presents a JSON with the format of the JSON file containing the exported data.

{
    "datareaders":{},
    "datawriters":{},
    "domains": {
        "0": {
            "alias":"0",
            "alive":true,
            "metatraffic":false
            "name":"0",
            "participants":[],
            "topics":[]
        }
    },
    "hosts":{},
    "locators":{},
    "participants":{},
    "processes":{},
    "topics":{},
    "users":{},
    "users":{},
}

Linux installation from sources¶

The instructions for installing the eProsima Fast DDS Monitor application from sources and the required Qt installation are provided in this page. It is organized as follows:

Dependencies installation
- Requirements
- Dependencies
Colcon installation
CMake installation
- Local installation
- Global installation
Run an application

Dependencies installation¶

Fast DDS Monitor depends on eProsima Fast DDS library, eProsima Fast DDS Statistics Backend library, Qt and certain Debian packages. This section describes the instructions for installing eProsima Fast DDS dependencies and requirements in a Linux environment from sources. The following packages will be installed:

foonathan_memory_vendor, an STL compatible C++ memory allocator library.
fastcdr, a C++ library that serializes according to the standard CDR serialization mechanism.
fastrtps, the core library of eProsima Fast DDS library.
fastdds_statistics_backend, a C++ library that provides a simple and easy-to-use API for interacting with data from Fast DDS statistics module

First of all, the Requirements and Dependencies detailed below need to be met. Afterwards, the user can choose whether to follow either the colcon or the CMake installation instructions.

Requirements¶

The installation of eProsima Fast DDS in a Linux environment from binaries requires the following tools to be installed in the system:

CMake, g++, pip, wget and git
Colcon [optional]
Gtest [for test only]

CMake, g++, pip, wget and git¶

These packages provide the tools required to install eProsima Fast DDS and its dependencies from command line. Install CMake, g++, pip, wget and git using the package manager of the appropriate Linux distribution. For example, on Ubuntu use the command:

sudo apt install cmake g++ pip wget git

Colcon¶

colcon is a command line tool based on CMake aimed at building sets of software packages. Install the ROS 2 development tools (colcon and vcstool) by executing the following command:

pip3 install -U colcon-common-extensions vcstool

Note

If this fails due to an Environment Error, add the --user flag to the pip3 installation command.

Gtest¶

Gtest is a unit testing library for C++. By default, eProsima Fast DDS Monitor does not compile tests. It is possible to activate them with the opportune CMake options when calling colcon or CMake. For more details, please refer to the CMake options section. For a detailed description of the Gtest installation process, please refer to the Gtest Installation Guide.

Dependencies¶

eProsima Fast DDS has the following dependencies, when installed from sources in a Linux environment:

Asio and TinyXML2 libraries
OpenSSL
eProsima dependencies
Qt 5.15

Asio and TinyXML2 libraries¶

Asio is a cross-platform C++ library for network and low-level I/O programming, which provides a consistent asynchronous model. TinyXML2 is a simple, small and efficient C++ XML parser. Install these libraries using the package manager of the appropriate Linux distribution. For example, on Ubuntu use the command:

sudo apt install libasio-dev libtinyxml2-dev

OpenSSL¶

OpenSSL is a robust toolkit for the TLS and SSL protocols and a general-purpose cryptography library. Install OpenSSL using the package manager of the appropriate Linux distribution. For example, on Ubuntu use the command:

sudo apt install libssl-dev

eProsima dependencies¶

If it already exists in the system an installation of Fast DDS library with version greater than 2.3.0 and an installation of Fast DDS Statistics Backend, just source these libraries when building the Fast DDS Monitor by using the command:

source <fastdds-installation-path>/install/setup.bash

In other case, just download Fast DDS project from sources and build it together with Fast DDS Monitor using colcon as it is explained in section Colcon installation.

Qt 5.15¶

Qt 5.15 is needed in order to build Fast DDS Monitor. To install this Qt version, refer to Qt Downloads website.

Note

When going through the installation steps, make sure the box of component Qt Charts is checked.

Colcon installation¶

Create a Fast-DDS-Monitor directory and download the .repos file that will be used to install eProsima Fast DDS Monitor and its dependencies:
```
mkdir -p ~/Fast-DDS-Monitor/src
cd ~/Fast-DDS-Monitor
wget https://raw.githubusercontent.com/eProsima/Fast-DDS-monitor/v1.5.0/fastdds_monitor.repos
vcs import src < fastdds_monitor.repos
```
Note

In case there is an already Fast DDS installation in the system it is not required to download and build every dependency in the .repos file. It is just needed to download and build the Fast DDS Monitor project having sourced its dependencies. Refer to section eProsima dependencies in order to check how to source Fast DDS and Fast DDS Statistics Backend libraries.

In order to build the project, it must be specified the path to the Qt 5.15 gcc_64 installation path. Using the standard Qt installation, this path should be similar to /home/<user>/Qt/5.15.2/gcc_64.

Build the packages:

colcon build --cmake-args -DQT_PATH=<qt-installation-path>

Note

Being based on CMake, it is possible to pass the CMake configuration options to the colcon build command. For more information on the specific syntax, please refer to the CMake specific arguments page of the colcon manual.

CMake installation¶

This section explains how to compile eProsima Fast DDS Monitor with CMake, either locally or globally.

Local installation¶

Create a Fast-DDS directory where to download and build eProsima Fast DDS Monitor and its dependencies:
```
mkdir ~/Fast-DDS-Monitor
```

Clone the following dependencies and compile them using CMake.

Foonathan memory

cd ~/Fast-DDS-Monitor
git clone https://github.com/eProsima/foonathan_memory_vendor.git
mkdir foonathan_memory_vendor/build
cd foonathan_memory_vendor/build
cmake .. -DCMAKE_INSTALL_PREFIX=~/Fast-DDS-Monitor/install -DBUILD_SHARED_LIBS=ON
cmake --build . --target install

Fast CDR

cd ~/Fast-DDS-Monitor
git clone https://github.com/eProsima/Fast-CDR.git
mkdir Fast-CDR/build
cd Fast-CDR/build
cmake .. -DCMAKE_INSTALL_PREFIX=~/Fast-DDS-Monitor/install
cmake --build . --target install

Fast DDS

cd ~/Fast-DDS-Monitor
git clone https://github.com/eProsima/Fast-DDS.git
mkdir Fast-DDS/build
cd Fast-DDS/build
cmake .. -DCMAKE_INSTALL_PREFIX=~/Fast-DDS-Monitor/install -DCMAKE_PREFIX_PATH=~/Fast-DDS-Monitor/install
cmake --build . --target install

Fast DDS Statistics Backend

cd ~/Fast-DDS-Monitor
git clone https://github.com/eProsima/Fast-DDS-statistics-backend.git
mkdir Fast-DDS-statistics-backend/build
cd Fast-DDS-statistics-backend/build
cmake .. -DCMAKE_INSTALL_PREFIX=~/Fast-DDS-Monitor/install -DCMAKE_PREFIX_PATH=~/Fast-DDS-Monitor/install
cmake --build . --target install

Once all dependencies are installed, install eProsima Fast DDS Monitor:

cd ~/Fast-DDS-Monitor
git clone https://github.com/eProsima/Fast-DDS-monitor.git
mkdir Fast-DDS-monitor/build
cd Fast-DDS-monitor/build
cmake .. \
    -DCMAKE_INSTALL_PREFIX=~/Fast-DDS-Monitor/install \
    -DCMAKE_PREFIX_PATH=~/Fast-DDS-Monitor/install \
    -DQT_PATH=<qt-installation-path>
cmake --build . --target install

Note

By default, eProsima Fast DDS Monitor does not compile tests. However, they can be activated by downloading and installing Gtest and building with CMake option -DBUILD_TESTS=ON.

Global installation¶

To install eProsima Fast DDS system-wide instead of locally, remove all the flags that appear in the configuration steps of Fast-CDR, Fast-DDS, Fast-DDS-Statistics-Backend, and Fast-DDS-Monitor, and change the first in the configuration step of foonathan_memory_vendor to the following:

-DCMAKE_INSTALL_PREFIX=/usr/local/ -DBUILD_SHARED_LIBS=ON

Run an application¶

To run the eProsima Fast DDS Monitor application, source the Fast DDS and Fast DDS Statistics Backend libraries and execute the executable file that has been installed in <install-path>/fastdds_monitor/bin/fastdds_monitor:

# If built has been done using colcon, all projects could be sourced as follows
source install/setup.bash
./<install-path>/fastdds_monitor/bin/fastdds_monitor

Be sure that this executable has execute permissions.

CMake options¶

eProsima Fast DDS Monitor provides numerous CMake options for changing the behavior and configuration of Fast DDS Monitor. These options allow the developer to enable/disable certain Fast DDS Monitor settings by defining these options to ON/OFF at the CMake execution, or set the required path to certain dependencies.

Warning

These options are only for developers who installed the Fast DDS Monitor following the compilation steps described in Linux installation from sources.

Option	Description	Possible values	Default
`QT_PATH`	Path to the directory where Qt has been installed. This argument is required to find the Qt binaries. An example of the path to the Qt 5.15 installation directory is: `/opt/Qt/5.15.2/gcc_64`.
`BUILD_TESTS`	Build the Fast DDS Monitor application and documentation tests. Setting `BUILD_TESTS` to `ON` sets `BUILD_DOCUMENTATION_TESTS` to `ON`.	`OFF` `ON`	`OFF`
`BUILD_APP_TESTS`	Build the Fast DDS Monitor application tests. It is set to `ON` if `BUILD_TESTS` is set to `ON`.	`OFF` `ON`	`OFF`
`BUILD_DOCUMENTATION_TESTS`	Build the Fast DDS Monitor documentation tests. It is set to `ON` if `BUILD_TESTS` is set to `ON`.	`OFF` `ON`	`OFF`
`BUILD_DOCUMENTATION`	Build the Fast DDS Monitor documentation. It is set to `ON` if `BUILD_TESTS_DOCUMENTATION` is set to `ON`.	`OFF` `ON`	`OFF`
`BUILD_MOCK`	Build the Fast DDS Statistics Backend mocks, which is a simulator of a Fast DDS application that generates random statistics data for testing the Fast DDS Monitor. It is set to `ON` if `BUILD_TESTS` is set to `ON`, `STATIC_MOCK` is set to `ON`, or `COMPLEX_MOCK` is set to `ON`.	`OFF` `ON`	`OFF`
`STATIC_MOCK`	Build the Fast DDS Statistics Backend static mock and link the Fast DDS Monitor application against it. The static mock is a simulator of a Fast DDS application that generates deterministic statistics data for testing the Fast DDS Monitor.	`OFF` `ON`	`OFF`
`COMPLEX_MOCK`	Build the Fast DDS Statistics Backend complex mock and link the Fast DDS Monitor application against it. The complex mock is a simulator of a Fast DDS application that random statistics data for testing the Fast DDS Monior	`OFF` `ON`	`OFF`

Fast DDS Monitor with ROS 2¶

Fast DDS Monitor is a useful tool for monitoring and studying a ROS 2 network. The automatic discovery of entities in a local network allows to easily see the different Participants that are running, as its Endpoints, the Topics that each one is using, and even the network interfaces they are using to communicate with each other. Additionally, one could receive statistical data from every endpoint in the network. This data is very useful to analyze the performance and seek any possible communication problem in the network.

ROS 2 relies on DDS communication protocol to communicate different nodes. There are different RMWs (ROS MiddleWare) available in the latest ROS 2 versions. Make sure you are using Fast DDS as your ROS 2 middleware in order to receive statistical data and monitor your network.

In the following sections, instructions for using Fast DDS with Statistics in different ROS2 versions are provided, as well as a brief tutorial demonstrating the integration of Fast DDS Monitor with ROS2 in a simple scenario.

Galactic¶

This section shows how to install and deploy some ROS 2 Galactic nodes in order to monitor them with Fast DDS Monitor.

Installation¶

First of all, follow the Fast DDS Monitor on Linux on this documentation to install Fast DDS Monitor.

Fast DDS is not installed by default in the ROS 2 Galactic release. Thus, first required step is to download Fast DDS and compile it with statistics.

Installation from sources¶

Follow the ROS 2 galactic installation from sources documentation Fast DDS is downloaded within the rest of the packages. The only consideration here is to compile fastrtps library with the Statistics Module activated. When compiling with colcon, the following arguments must be provided:

colcon build --symlink-install --cmake-args -DFASTDDS_STATISTICS=ON

Execution¶

We are going to recreate a simple DDS network with one talker and one listener from ROS 2 demo nodes.

Execute Fast DDS Monitor¶

Initiate Fast DDS Monitor by running the executable file created in the installation process. Once Fast DDS Monitor is launched, start a monitor in domain 0 (default domain).

Execute ROS 2 demo nodes with statistics¶

To execute ROS 2 nodes with statistics two aspects of the configuration must be taken into account:

The middleware used must be Fast DDS, set through an environment variable.
In order to activate the publication of statistical data, Fast DDS requires an environment variable specifying those kinds of statistical data to be reported.

To execute each of the nodes, run the following commands in different terminals:

export RMW_IMPLEMENTATION=rmw_fastrtps_cpp

export FASTDDS_STATISTICS="HISTORY_LATENCY_TOPIC;NETWORK_LATENCY_TOPIC;PUBLICATION_THROUGHPUT_TOPIC;\
SUBSCRIPTION_THROUGHPUT_TOPIC;RTPS_SENT_TOPIC;RTPS_LOST_TOPIC;\
HEARTBEAT_COUNT_TOPIC;ACKNACK_COUNT_TOPIC;NACKFRAG_COUNT_TOPIC;\
GAP_COUNT_TOPIC;DATA_COUNT_TOPIC;RESENT_DATAS_TOPIC;SAMPLE_DATAS_TOPIC;\
PDP_PACKETS_TOPIC;EDP_PACKETS_TOPIC;DISCOVERY_TOPIC;PHYSICAL_DATA_TOPIC"

ros2 run demo_nodes_cpp listener

export RMW_IMPLEMENTATION=rmw_fastrtps_cpp

export FASTDDS_STATISTICS="HISTORY_LATENCY_TOPIC;NETWORK_LATENCY_TOPIC;PUBLICATION_THROUGHPUT_TOPIC;\
SUBSCRIPTION_THROUGHPUT_TOPIC;RTPS_SENT_TOPIC;RTPS_LOST_TOPIC;\
HEARTBEAT_COUNT_TOPIC;ACKNACK_COUNT_TOPIC;NACKFRAG_COUNT_TOPIC;\
GAP_COUNT_TOPIC;DATA_COUNT_TOPIC;RESENT_DATAS_TOPIC;SAMPLE_DATAS_TOPIC;\
PDP_PACKETS_TOPIC;EDP_PACKETS_TOPIC;DISCOVERY_TOPIC;PHYSICAL_DATA_TOPIC"

ros2 run demo_nodes_cpp talker

Remember to source your ROS 2 installation before every ros2 command.

Monitoring network¶

Now one should see in the DDS Panel two new Participants.

Alias¶

Participants in ROS 2 are named / by default. In order to differentiate them one could change the alias of the Participant (see Change entity alias). The talker would be the one with one writer, and the listener the one with a reader.

Physical data¶

In order to see the information of the host and the physical context where every node is running, go to the Explorer Panel and activate the Physical Panel. There, the host, user and process of each node are displayed.

Statistical data¶

To show statistical data about the communication between the talker and the listener, follow the steps to Create Dynamic Series Chart and plot this statistical data in a real time chart.

Introspect metatraffic topics¶

Fast DDS Monitor filters by default the topics used for sharing metatraffic and the endpoints related to them so the user can inspect their network easily. These topics are the ones that ROS 2 uses for discovery and configuration purposes, such as ros_discovery_info, as well as those used by Fast DDS to report statistical data.

In order to see these topics in the monitor, click View->Show Metatraffic menu button (see Hide/Show Metatraffic). Now, these topics are shown in the logical panel, and also the Readers and Writers associated to them under their respective Participants.

Video Tutorial¶

There is a video tutorial going through the steps described in this section.

eProsima Docker Image¶

eProsima provides the eProsima Fast DDS Suite Docker image for those who want a quick demonstration of Fast DDS running on an Ubuntu platform. It can be downloaded from eProsima’s downloads page.

This Docker image was built for Ubuntu 20.04 (Focal Fossa).

To run this container you need Docker installed. From a terminal run

$ sudo apt install docker.io

Fast DDS Suite¶

This Docker image contains the complete Fast DDS suite. This includes:

eProsima Fast DDS libraries and examples: eProsima Fast DDS is a C++ implementation of the DDS (Data Distribution Service) Specification, a protocol defined by the Object Management Group (OMG). The eProsima Fast DDS library provides both an Application Programming Interface (API) and a communication protocol that deploy a Data-Centric Publisher-Subscriber (DCPS) model, with the purpose of establishing efficient and reliable information distribution among Real-Time Systems. eProsima Fast DDS is predictable, scalable, flexible, and efficient in resource handling.

This Docker Image contains the Fast DDS libraries bundled with several examples that showcase a variety of capabilities of eProsima’s Fast DDS implementation.

You can read more about Fast DDS on the Fast DDS documentation page.
Shapes Demo: eProsima Shapes Demo is an application in which Publishers and Subscribers are shapes of different colors and sizes moving on a board. Each shape refers to its own topic: Square, Triangle or Circle. A single instance of the eProsima Shapes Demo can publish on or subscribe to several topics at a time.

You can read more about this application on the Shapes Demo documentation page.
Fast DDS Monitor: eProsima Fast DDS Monitor is a graphical desktop application aimed at monitoring DDS environments deployed using the eProsima Fast DDS library. Thus, the user can monitor in real time the status of publication/subscription communications between DDS entities. They can also choose from a wide variety of communication parameters to be measured (latency, throughput, packet loss, etc.), as well as record and compute in real time statistical measurements on these parameters (mean, variance, standard deviation, etc.).

To load this image into your Docker repository, from a terminal run

$ docker load -i ubuntu-fastdds-suite:<FastDDS-Version>.tar

You can run this Docker container as follows

$ xhost local:root
$ docker run -it --privileged -e DISPLAY=$DISPLAY -v /tmp/.X11-unix:/tmp/.X11-unix \
ubuntu-fastdds-suite:<FastDDS-Version>

From the resulting Bash Shell you can run each feature.

Fast DDS Examples¶

Included in this Docker container is a set of binary examples that showcase several functionalities of the Fast DDS libraries. These examples’ path can be accessed from a terminal by typing

$ goToExamples

From this folder you can access all examples, both for DDS and RTPS. We detail the steps to launch two such examples below.

Hello World Example¶

This is a minimal example that will perform a Publisher/Subscriber match and start sending samples.

$ goToExamples
$ cd HelloWorldExample/bin
$ tmux new-session "./HelloWorldExample publisher 0 1000" \; \
split-window "./HelloWorldExample subscriber" \; \
select-layout even-vertical

This example is not constrained to the current instance. It is possible to run several instances of this container to check the communication between them by running the following from each container.

$ goToExamples
$ cd HelloWorldExample/bin
$ ./HelloWorldExample publisher

or

$ goToExamples
$ cd HelloWorldExample/bin
$ ./HelloWorldExample subscriber

Benchmark Example¶

This example creates either a Publisher or a Subscriber and on a successful match starts sending samples. After a few seconds the process that launched the Publisher will show a report with the number of samples transmitted.

On the subscriber side, run:

$ goToExamples
$ cd Benchmark/bin
$ ./Benchmark subscriber udp

On the publisher side, run:

$ goToExamples
$ cd Benchmark/bin
$ ./Benchmark publisher udp

Shapes Demo¶

To launch the Shapes Demo, from a terminal run

$ ShapesDemo

eProsima Shapes Demo usage information can be found on the Shapes Demo First Steps.

Fast DDS Monitor¶

To launch the Fast DDS Monitor, from a terminal run

$ fastdds_monitor

eProsima Fast DDS Monitor usage information can be located on the Fast DDS Monitor User Manual.

Version v1.5.0¶

This release includes the following features:

Schedule the dump of the database information to a JSON file.

This release includes the following dependencies update:

	Repository	Old Version	New Version
Foonathan Memory Vendor	eProsima/foonathan_memory_vendor	v1.3.0	v1.3.1
Fast CDR	eProsima/Fast-CDR	v1.0.27	v1.1.0
Fast DDS	eProsima/Fast-DDS	v2.10.1	v2.11.0
Fast DDS Statistics Backend	eProsima/Fast-DDS-statistics-backend	v0.10.0	v0.11.0

Previous versions¶

Version v1.4.0¶

This release includes the following features:

Button to dump the information from the database to a JSON file.
Button to remove inactive entities from the database.
Button to clear the statistical data of all the entities.
Button to schedule the removal of old data every x seconds.
Support for limiting data points in dynamic data series.

Version v1.3.0¶

This release includes the following bug fixes:

Fix error in y-axis resize that went to infinite.

This release includes the following new internal changes:

Upgrade Fast DDS v2.8.0 to Fast DDS v2.9.0.
Upgrade Fast DDS Statistics Backend v0.7.1. to Fast DDS Statistics Backend v0.8.0.

Version v1.2.0¶

This release includes the following new documentation sections:

Guide to solve the non-reception of statistics data after enabling them.

This release includes the following new internal changes:

Upgrade Fast DDS v2.7.0 to Fast DDS v2.8.0.
Upgrade Fast DDS Statistics Backend v0.7.0 to Fast DDS Statistics Backend v0.7.1.

Version v1.2.0¶

This release includes the following new documentation sections:

Windows installation guide.

This release includes the following new minor features:

Windows app icon.
Support GTest new version.

This release includes the following bugfixes:

Fixes included in Fast DDS Statistics Backend v1.2.0.

Version v1.1.0¶

This release includes the following new features:

Add Hide/Show metatraffic entities capabilities.
Support cumulative data in Dynamic Charts.

This release includes the following improvements:

Application background
Move last clicked logic from QML to C++.
Blank text when open “change alias” dialog.
Documentation improvement:
- Fast DDS Suite documentation.
- Tutorial for ROS 2 galactic.

This release includes the following bugfixes:

Fix Y axis rendering when all values were 0.
Fix timestamps in Historical charts.
Fix deselect entity minor bugs.
Fix width QML warning.
Fix mu(micro) symbol display in Windows

Version v1.0.0¶

This is the first stable release of eProsima Fast DDS Monitor.

Version v0.2.0¶

This release includes the following improvements:

Add ToolTips for dialog parameters
Add Real-Time charts
Refactor sidebars * New left sidebar with all the DDS, physical and logical entities together with its corresponding information. * Separated panel for Fast DDS Monitor status. * New panel to display Issues information.
Possibility to change the Entity name setting an alias for it.
Entities not alive are marked in gray color.
Possibility to display/hide the not alive entities.
Entity menu displayed right-clicking on them.
Support for Windows platforms.
Resizable charts in three different sizes: full screen, two chart boxes per row and three chart boxes per row.
Display two chart boxes in a row by default.
Re-nameable chart boxes.
Export charts data to CSV. It is possible to export a single series, a whole ChartBox or all ChartBoxes of the monitor to a single CSV file.
Change the cursor shape when hovering over the legend and when action buttons are pressed over the selected chart.
Add information button on each ChartBox.
Normalize Y axis.
Button to set axes in the ChartView.
Button to reset zoom.
Maximize and minimize chart boxes.
Initialize monitor in a Discovery Server network.

This release includes the following bugfixes:

Get correct Entity Id on the add statistics series dialog.
Set correct Entity Id on the add statistics series dialog.
Icons colorization in Windows platforms.
Avoid launch a command prompt when the application is executed in Windows.
TreeModels refactor * Convert all arrays to dictionaries with the array index as the element key. * Fix item duplication when collapsed.
When receiving data from a new entity, it is added to its corresponding entity model as an additional model item instead of destroying and rebuilding the entire model.
Avoid destroy ChartBoxes when they are out of the view.
Increase Y axis in historic ChartBoxes so all the data is visible.
Refactor Historic series so all the internal data is deleted when graphics are removed.
Increased the number of characters for series labels.
Change displayed chart units for some DataKinds.
Add units to the statistics entity summary.
Charts dashboard layout scroll bar always visible.
Sort data from backend.
When receiving data of DataKinds that are measured in counts, the data points that are NaN are replaced by 0.

Version v0.1.0¶

This is the first release of eProsima Fast DDS Monitor.

This release includes several features regarding the monitoring of DDS network and the visualization of a real time working network, as instrumentation data related with this network:

This release includes the following visual features

Visual Interface to monitor a DDS network.
Visualize alive entities in a DDS network in real time.
Represent instrumentation data of several kinds of a DDS network:
- Latency
- Throughput
- Data sent
- Metadata sent
- Discovery time
Represent instrumentation data regarding different cumulative functions:
- Mean
- Median
- Standard deviation
- Maximum
- Minimum
- Count
- Sum
Real time events:
- New entities discovered.
- New issues detected.

This release includes the following interactive features

Initiate monitoring a DDS network:
- Monitoring a DDS domain.
- Monitoring a Discovery Server network.
Represent any data kind with any cumulative function regarding any one or two entities in the network.
Select an Entity in order to retrieve information about the entity configuration and its data summary.
User friendly modifiable layout:
- Resize windows and panels.
- Create, delete and move charts and panels.