Terms and Concepts for Persistence

The following terms and concepts are useful for understanding persistence:

Space State
Indicates whether the space can accept regular space operations or not. This happens only when the space is in READY state.
Persistence Type
Defines what type of persistence ActiveSpaces uses. Shared-all and shared-nothing are the supported types. Only one type of persistence can be configured on the same space at the same time.
Persistence Policy
Defines how the changes to space will be persisted—synchronously or asynchronously.
Member Name
A unique name to identify each node/seeder/member. Recommended if using shared-nothing persistence.
Data Store
The file system/directory location where ActiveSpaces stores the persistence files.
Data Loss
Data loss is detected by ActiveSpaces when the number of nodes (seeders) that either leave or fail (due to a crash) exceeds the count set for the space. In this situation, the space is marked as FAILED.
Space Recovery
ActiveSpaces recovers a space (based on user intervention) when the space state is FAILED either due to data loss or cluster startup.
Space Resume
ActiveSpaces resumes a space (based on user intervention) when the space goes into a SUSPENDED mode due to loss of a persister.
Related concepts