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1. The whole cluster allowed only one cluster-wide snapshot operation per time.
2. Encrypted caches currently not allowed due to required additional changes to merge cache partition with its delta file.
3. The cache stop operation is not allowed during the ongoing cluster snapshot. An exception will be thrown to users on the cache stop attempt.
4. The cluster snapshot operation will be stopped if some of the baseline nodes left or fail prior to reporting about their local snapshot completion. Partial local snapshots will be reverted.

Automatic snapshot restore process

Restore cache group(s) from the snapshot

We need to provide the ability to restore individual cache groups from an existing snapshot.

Process overview

The overall process must include the following sequential steps:

1. Make sure that all partitions of the cache group are available in the cluster and there are no conflicts in the saved cache configurations. Make sure the target cache group doesn't exist (user must manually destroy the cache before restoring).
2. Copy the cache data files between nodes according to required partition distribution and merge binary metadata.
3. Dynamically start the restored cache group(s).

If errors occur (I/O errors, node failure, etc.), the changes made to the cluster must be fully or partially reverted (depending on the type of error).

Requirements

The cluster should be active

Limitations

Restore operation will be rejected if the restored cache/group already present in the cluster. The user must manually destroy it and restart the operation.

Failover

// TBD

Whole cluster restore

// TBD

Discussion Links

http://apache-ignite-developers.2346864.n4.nabble.com/DISCUSSION-Hot-cache-backup-td41034.html

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