eProsima Non-Intrusive DDS Recorder Documentation¶
eProsima Non-Intrusive DDS Recorder is a tool that records all the DDS traffic in a network using a non-intrusive mechanism, allowing a user to test, analyze or log a DDS distributed system without adding any new DDS participant or service. Because no entity is added to the network, the recorded data reflects the real behavior and timing of the system under study.
eProsima Non-Intrusive DDS Recorder sniffs the DDS wire protocol (RTPS) instead of subscribing to the topics of interest. It dissects the protocol, builds a complete database of all the DDS entities (Participants, Publishers, Subscribers and Topics), the data types and all the exchanged messages, and stores the result in a SQLite database that can be inspected with any standard SQL client.
Commercial support¶
Looking for commercial support? Write us to info@eprosima.com
Find more about us at eProsima’s webpage.
Overview¶
eProsima Non-Intrusive DDS Recorder does not record raw network data: it builds a message table for each DDS Topic, with the same fields as the corresponding DDS Topic data type. The application provides the following features:
Non-intrusive capture. Traffic is taken from a packet capture (PCAP) file produced by a network sniffer, so no DDS entity is created and the observed system is not modified in any way. In order to capture all the traffic in a network, the switch debug port should be sniffed; otherwise only the traffic directed to the node where the sniffer runs is obtained.
Automatic entity discovery. DDS uses an automatic discovery process to announce all the DDS entities in a network. eProsima Non-Intrusive DDS Recorder analyzes the discovery traffic to learn which topics exist and which DataWriters and DataReaders serve them, so every sample it captures can be attributed to a topic. Supply an IDL file with the type definitions to have the samples deserialized into columns as well.
Human readable output. The RTPS messages are translated into a human readable format and stored in a SQLite database. Both the discovery information and the user data are available as regular SQL tables, so the recorded session can be queried, filtered and post-processed with any tool able to read a SQLite file.
Note
This release requires an external sniffer, such as Wireshark, to save the network traffic into a standard packet capture file. Future releases will include a built-in sniffer to process the network packets in real time.
A recording session therefore has three steps: capture the traffic with a sniffer, run the application on the resulting file, and query the database it produces.
# 1. Capture the DDS traffic, keeping whole packets
sudo tcpdump -i eth0 -s 0 -w capture.pcap udp
# 2. Translate the capture into a SQLite database
ni_ddsrecorder -db session.db capture.pcap
# 3. Query the result
sqlite3 session.db "SELECT name, type FROM Topics;"
Contributing to the documentation¶
Non-Intrusive DDS Recorder 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.
Installation Manual: requirements and installation instructions for Windows and Linux.
User Manual: how the tool works, when to use it, how to obtain a usable capture, the command line reference, the structure of the generated database, the supported data types, a collection of SQL recipes to analyze a recorded session, and the limitations of the current release.
Release Notes: supported platforms, databases, DDS implementations and capture formats.
Glossary: the nomenclature used throughout this documentation.
New users are advised to start with Introduction, which explains what the application records and links to the rest of the User Manual in reading order.