What Dual Commit is

Dual Commit functionality is designed to prevent the loss of object data if an object's initial storage location fails before the object can be evaluated against the active ILM policy. As soon as an object is ingested, a second copy of object data is created and distributed to a different Storage Node.

Simultaneously, the object is queued for ILM evaluation. When the object is matched by an ILM rule in the active policy, object copies are created and distributed per the instructions in the rule. The Dual Commit copy is deleted (unless its current location satisfies the placement instruction in the rule).

If the request to create the Dual Commit copies fails (for example, a network issue prevents the second initial copy from being made), the StorageGRID Webscale system does not retry and ingest fails.

Dual Commit is enabled by default. If ILM rules are configured to only store one instance of replicated object data, you can disable Dual Commit to avoid unnecessarily creating and then deleting copies generated by the Dual Commit operation. For configuration information, see the appropriate StorageGRID Webscale API guide.