==== Durability ====
[[ddsf:public:guidebook:06_append:glossary:start| Return to Glossary ]]

Responsible for maintaining historical data between services and 
providing historical data to late joining applications. 
Specifies if [[ddsf:public:guidebook:06_append:glossary:s:sample|Samples]] should outlive their [[ddsf:public:guidebook:06_append:glossary:d:data_writer|Data Writers]] for late 
joiners. The longer a sample lives the greater the overhead passed 
to the [[ddsf:public:guidebook:06_append:glossary:d: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 [[ddsf:public:guidebook:06_append:glossary:d:data_reader]].
  ; Transient Local
    : Data [[ddsf:public:guidebook:06_append:glossary:i:instance|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: [[https://istkb.adlinktech.com/article/vortex-opensplice-dds-glossary/ | OpenSplice Glossary]]