[HDFS-15439] Setting dfs.mover.retry.max.attempts to negative value will retry forever.

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 3.3.1, 3.4.0, 3.2.3
• Component/s: balancer & mover
• Hadoop Flags: Reviewed
• Assignee: AMC-team
• Reporter: AMC-team
• Created: 25/Jun/20 17:28
• Updated: 10/Jun/21 07:43
• Resolved: 15/Aug/20 09:45

Description

Configuration parameter "dfs.mover.retry.max.attempts" is to define the maximum number of retries before the mover consider the move failed. There is no checking code so this parameter can accept any int value.

Theoratically, setting this value to <=0 should mean that no retry at all. However, if you set the value to negative value. The checking condition for retry failed will never satisfied because the if statement is "if (retryCount.get() == retryMaxAttempts)". The retry count will always +1 by retryCount.incrementAndGet() after failed but never = retryMaxAttempts. 

private Result processNamespace() throws IOException {
      ... //wait for pending move to finish and retry the failed migration
      if (hasFailed && !hasSuccess) {
        if (retryCount.get() == retryMaxAttempts) {
          result.setRetryFailed();
          LOG.error("Failed to move some block's after "
              + retryMaxAttempts + " retries.");
          return result;
        } else {
          retryCount.incrementAndGet();
        }
      } else {
        // Reset retry count if no failure.
        retryCount.set(0);
      }
      ...
    }

How to fix

Add checking code of "dfs.mover.retry.max.attempts" to accept only non-negative value or change the if statement condition when retry count exceeds max attempts.