[jira] [Created] (HBASE-25014) ScheduledChore is never triggered when initalDelay > 1.5*period

["Sun Xin (Jira)" <ji...@apache.org>]

Sun Xin created HBASE-25014:
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             Summary: ScheduledChore is never triggered when initalDelay > 1.5*period
                 Key: HBASE-25014
                 URL: https://issues.apache.org/jira/browse/HBASE-25014
             Project: HBase
          Issue Type: Bug
    Affects Versions: 2.2.5, 2.2.4, 2.2.3, 3.0.0-alpha-1
            Reporter: Sun Xin
            Assignee: Sun Xin
             Fix For: 3.0.0-alpha-1


In our recent tests, ScheduledChore is never triggered when initalDelay > 1.5*period.

The cause of the bug is the following:

The trigger time for a ScheduleChore must be within an acceptable time window that is 1.5 * period. see [here|https://github.com/apache/hbase/blob/e5ca9adc54f9f580f85d21d38217afa97aa79d68/hbase-common/src/main/java/org/apache/hadoop/hbase/ScheduledChore.java#L234]

timeOfLastRun and timeOfThisRun are two variables that record two adjacent trigger time. [The first initialization of timeOfThisRun|https://github.com/apache/hbase/blob/e5ca9adc54f9f580f85d21d38217afa97aa79d68/hbase-common/src/main/java/org/apache/hadoop/hbase/ScheduledChore.java#L273] is when the ScheduleChore is created, it's not a real trigger time.

If we set initialDelay > 1.5 period , after initialDelay, the first time when chore is triggered has exceeded the allowed window. Then [cancel the chore and schedule it again|https://github.com/apache/hbase/blob/e5ca9adc54f9f580f85d21d38217afa97aa79d68/hbase-common/src/main/java/org/apache/hadoop/hbase/ChoreService.java#L176].

So it's stuck in loop when initialDelay > 1.5 period :

1.  init timeOfThisRun at a wrong time.

2. wait initalDelay

3. chore trigger, but exceeded the allowed window.

4. cancel chore and schedule it again

5. go step 1.

 



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