Overview of Storage Container Manager in High Availability

Configuring High Availability (HA) for the Storage Container Manager (SCM) prevents the occurrence of a single point of failure in an Ozone cluster to manage the various types of storage metadata, and ensures continued interactions of the SCM with the Ozone Manager (OM) and the DataNodes.

SCM HA involves the following:
  • A leader SCM that interacts with the OM for block allocations, and works with the DataNodes to maintain the replication levels required by the Ozone cluster.
  • At least two follower SCMs that closely keep track of the updates made by the leader so that in the event of a failure, one of the follower nodes can take over the operations from the leader.