Disaster Recovery

Disaster Recovery is a situation where a set of running systems must be replaced by another set of running systems due to failure, damage, loss of connectivity, or other traumatic event. To set up disaster recovery, ActiveSpaces uses the concept of gridsets. A gridset is a group of data grids that share the same set of consistent data. In a disaster recovery setup, a gridset comprises a primary grid and at least one mirror grid.

Primary Grid

A data grid that is listed as the primary grid of a gridset is a primary grid. All operations included in the ActiveSpaces API are permitted on primary grids.

Mirror Grid
A data grid that is included in a gridset but is not currently the primary grid of that gridset is a mirror grid. The mirror grid is also referred to as a disaster recovery (DR) grid. Data received at a DR grid is a logically consistent checkpoint of the data from the primary grid (no partially committed transactions). For more information about checkpoints, see Checkpoints. Only read operations are allowed on mirror grids (for example, GET, queries, iterators). Read operations are run against the most recent checkpoint that has been mirrored from the primary grid.
For more information about gridsets and types of grids, see "Disaster Recovery Concepts" in TIBCO ActiveSpaces® - Enterprise Edition Concepts

Note: When a grid is added to a gridset, it cannot execute the Live Backup and Restore steps. With DR/mirroring, the grids in the gridset stay in sync with each other so the checkpoints taken by primary and mirror grids in a gridset do not include the required restore information needed for the Live Backup and Restore process.