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https://issues.apache.org/jira/browse/HIVE-26509?focusedWorklogId=812320&page=com.atlassian.jira.plugin.system.issuetabpanels:worklog-tabpanel#worklog-812320
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ASF GitHub Bot logged work on HIVE-26509:
-----------------------------------------
Author: ASF GitHub Bot
Created on: 27/Sep/22 02:41
Start Date: 27/Sep/22 02:41
Worklog Time Spent: 10m
Work Description: dengzhhu653 commented on code in PR #3567:
URL: https://github.com/apache/hive/pull/3567#discussion_r980676435
##########
standalone-metastore/metastore-common/src/main/java/org/apache/hadoop/hive/metastore/conf/MetastoreConf.java:
##########
@@ -1523,6 +1531,11 @@ public enum ConfVars {
TXN_USE_MIN_HISTORY_LEVEL("metastore.txn.use.minhistorylevel",
"hive.txn.use.minhistorylevel", true,
"Set this to false, for the TxnHandler and Cleaner to not use
MinHistoryLevel table and take advantage of openTxn optimisation.\n"
+ "If the table is dropped HMS will switch this flag to false."),
+ LOCK_NUMRETRIES("metastore.lock.numretries", "hive.lock.numretries", 100,
Review Comment:
the retries are intended to test whether we can lock on the given table,
https://github.com/apache/hive/blob/bcbdd0c77f73ce7f46342cc30d6c565027fac311/standalone-metastore/metastore-server/src/main/java/org/apache/hadoop/hive/metastore/leader/LeaseLeaderElection.java#L173-L189
the 100 retries are inspired from
[hive.lock.numretries](https://github.com/apache/hive/blob/master/common/src/java/org/apache/hadoop/hive/conf/HiveConf.java#L2922).
Issue Time Tracking
-------------------
Worklog Id: (was: 812320)
Time Spent: 2h 40m (was: 2.5h)
> Introduce dynamic leader election in HMS
> ----------------------------------------
>
> Key: HIVE-26509
> URL: https://issues.apache.org/jira/browse/HIVE-26509
> Project: Hive
> Issue Type: New Feature
> Components: Standalone Metastore
> Reporter: Zhihua Deng
> Priority: Major
> Labels: pull-request-available
> Time Spent: 2h 40m
> Remaining Estimate: 0h
>
> From HIVE-21841 we have a leader HMS selected by configuring
> metastore.housekeeping.leader.hostname on startup. This approach saves us
> from running duplicated HMS's housekeeping tasks cluster-wide.
> In this jira, we introduce another dynamic leader election: adopt hive lock
> to implement the leader election. Once a HMS owns the lock, then it becomes
> the leader, carries out the housekeeping tasks, and sends heartbeats to renew
> the lock before timeout. If the leader fails to reclaim the lock, then stops
> the already started tasks if it has, the electing event is audited. We can
> achieve a more dynamic leader when the original goes down or in the public
> cloud without well configured property, and reduce the leader’s burdens by
> running these tasks among different leaders.
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