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Responsible for maintaining historical data between services and providing historical data to late joining applications. Specifies if Samples should outlive their Data Writers for late joiners. The longer a sample lives the greater the overhead passed to the Data Distribution Service (DDS) becomes as it moves from dropping samples, to keeping them in shared memory, to writing them to hard disk. Provided variants include:

Volatile

No need to keep Samples for late joining Data Reader.

Transient Local

Data instance availability for late joining data reader is tied to the DataWriter availability.

Transient

Data sample availability outlives the data writer.

Persistent

Data sample availability outlives system restarts.

Source: OpenSplice Glossary