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title: SCM HA support summary: HA for Storage Container Manager using Ratis to replicate data date: 2020-03-05 jira: HDDS-2823 status: implementing author: Li Cheng, Nandakumar Vadivelu, Rui Wang, Glen Geng, Shashikant Banerjee

Abstract

Proposal to implement HA similar to the OM HA: Using Apache Ratis to propagate the

Links

The main SCM HA design doc is available from here

During the implementation of SCM-HA many smaller design docs are created specific to various areas:

• SCM HA Distributed Sequence ID Generator: about generating unique identifier across multiple nodes of the HA quorum
• SCM HA Service Manager: about starting and stopping the main SCM services (like PipelienManager, ReplicationManager) in case of a failover
• SCM HA SCMContext: about using a helper object which includes all the key information for all the required service components
• SCM HA Snapshots: about RAFT state-machine snapshots
• SCM HA: DeleteBlockLog: about coordinating block deletions in HA environment
• SCM HA: bootstrap: about initializing the SCM HA cluster