Persistence Service is a Connext DDS application that saves DDS data samples to transient or permanent storage, so they can be delivered to subscribing applications that join the system at a later time—even if the publishing application has already terminated.
Persistence Service runs as a separate application; you can run it on the same node as the publishing application, the subscribing application, or some other node in the network.
When configured to run in PERSISTENT mode, Persistence Service can use the filesystem or a relational database that provides an ODBC driver. For each persistent topic, it collects all the data written by the corresponding persistent DataWriters and stores them into persistent storage. See the RTI Persistence Service Release Notes for the list of platforms and relational databases that have been tested.
When configured to run in TRANSIENT mode, Persistence Service stores the data in memory.
The following chapters assume you have a basic understanding of DDS terms such as DomainParticipants, Publishers, DataWriters, Topics, and Quality of Service (QoS) policies. For an overview of DDS terms, please see Data-Centric Publish-Subscribe Communications. You should also have already read Mechanisms for Achieving Information Durability and Persistence.
© 2018 RTI