The InitShardMaster step initializes the quorum by electing a primary and setting up replication for the replicas. Additionally, a database is created to store the data for the keyspace-shard. The default name for the database will be
vt_ followed by the keyspace. In our use case, it would be
vt_commerce. You can override this default by providing an
init_db_name_override flag to vttablet. However, all future invocations must continue to supply this parameter.
The command for
InitShardMaster is as follows:
vtctlclient \ InitShardMaster \ -force \ commerce/0 \ cell1-100
Until this command is run, you may also see errors like this in the vttablet logs:
Cannot start query service: Unknown database 'vt_xxx'. This is because the database will be created only after a primary is elected.
If you have semi-sync enabled and did not set up at least three replicas, InitiShardMaster could hang indefinitely. Even if it succeeds, future operations that perform failovers could cause this shard to go into a deadlocked state.
After this step, visiting the
/debug/status page on the vttablets should show all the tablets as healthy:
InitShardMasteris a destructive command that resets all servers by deleting their binlog metadata. It should only be used for initializing a brand new cluster.
InitShardMasterwill soon be deprecated. This action will be performed automatically by
vtorconce it is released as production-ready.