[HBASE-7382] Port ZK.multi support from HBASE-6775 to 0.96

• Type: Bug
• Status: Closed
• Priority: Critical
• Resolution: Fixed
• Fix Version/s: 0.95.0
• Component/s: Zookeeper
• Hadoop Flags: Reviewed

Release Note

hbase.zookeeper.useMulti

Instructs HBase to make use of ZooKeeper's multi-update functionality.
    This allows certain ZooKeeper operations to complete more quickly and prevents some issues
    with rare Replication failure scenarios (see the release note of HBASE-2611 for an example).
    IMPORTANT: only set this to true if all ZooKeeper servers in the cluster are on version 3.4+
    and will not be downgraded. ZooKeeper versions before 3.4 do not support multi-update and will
    not fail gracefully if multi-update is invoked (see ZOOKEEPER-1495).

• Assignee: Himanshu Vashishtha
• Reporter: Gregory Chanan
• Created: 18/Dec/12 20:16
• Updated: 23/Sep/13 18:30
• Resolved: 25/Jan/13 05:55

Description

HBASE-6775 adds support for ZK.multi ZKUtil and uses it for the 0.92/0.94 compatibility fix implemented in HBASE-6710.

ZK.multi support is most likely useful in 0.96, but since HBASE-6710 is not relevant for 0.96, perhaps we should find another use case first before we port.

Issue Links

• is related to: HBASE-6775 Use ZK.multi when available for HBASE-6710 0.92/0.94 compatibility fix
• relates to: HBASE-2611 Handle RS that fails while processing the failure of another one