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https://issues.apache.org/jira/browse/PHOENIX-8025?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Tanuj Khurana resolved PHOENIX-8025.
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Resolution: Fixed
> Skip consistent-failover log replication for PARALLEL HA groups on the active
> cluster
> -------------------------------------------------------------------------------------
>
> Key: PHOENIX-8025
> URL: https://issues.apache.org/jira/browse/PHOENIX-8025
> Project: Phoenix
> Issue Type: Sub-task
> Reporter: Lokesh Khurana
> Assignee: Tanuj Khurana
> Priority: Major
>
> On the PHOENIX-7562 feature branch,
> IndexRegionObserver#getReplicationLogGroup decides whether a mutation batch
> that carries an HA group name is written to the consistent-failover
> replication log and shipped to the peer cluster. It checks the HA policy only
> when the local cluster is not active for the group:
> * Active cluster, any policy: the batch goes to the ReplicationLogGroup and
> is synchronously written to the peer's replication log.
> * Non-active cluster, PARALLEL: the batch is committed locally and not
> shipped.
> * Non-active cluster, FAILOVER: the batch is rejected (split-brain guard).
> A PARALLEL HA group does not need this replication. The client writes every
> mutation to both clusters, and PARALLEL tables are expected to have HBase
> native replication to keep the clusters converged. Shipping the active's
> PARALLEL writes through the replication log as well means:
> * Each PARALLEL write on the active waits for an extra synchronous write to
> the peer's file system before it returns.
> * The standby applies every write three times: the client's own write, HBase
> native replication, and the replication-log replay.
> * PARALLEL groups pick up the replication log's failure modes. For example, a
> failure writing to the peer's file system can make the region server
> fail-stop, even though PARALLEL never relies on the log.
> Testing on a pair of clusters with the feature branch deployed showed this
> directly: the active cluster's ReplicationLogGroup for a PARALLEL group
> appended every client write (1,049 and 651 appends on two region servers),
> and the standby replayed 1,268 replication-log files for that group, on top
> of the client's direct writes and HBase native replication
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