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Posted to common-issues@hadoop.apache.org by "Jonathan Hung (JIRA)" <ji...@apache.org> on 2017/09/01 20:45:00 UTC

[jira] [Created] (HADOOP-14828) RetryUpToMaximumTimeWithFixedSleep is not bounded by maximum time

Jonathan Hung created HADOOP-14828:
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             Summary: RetryUpToMaximumTimeWithFixedSleep is not bounded by maximum time
                 Key: HADOOP-14828
                 URL: https://issues.apache.org/jira/browse/HADOOP-14828
             Project: Hadoop Common
          Issue Type: Bug
            Reporter: Jonathan Hung


In RetryPolicies.java, RetryUpToMaximumTimeWithFixedSleep is converted to a RetryUpToMaximumCountWithFixedSleep, whose count is the maxTime / sleepTime: {noformat}    public RetryUpToMaximumTimeWithFixedSleep(long maxTime, long sleepTime,
        TimeUnit timeUnit) {
      super((int) (maxTime / sleepTime), sleepTime, timeUnit);
      this.maxTime = maxTime;
      this.timeUnit = timeUnit;
    }
{noformat}
But if retries take a long time, then the maxTime passed to the RetryUpToMaximumTimeWithFixedSleep is exceeded.

As an example, while doing NM restarts, we saw an issue where the NMProxy creates a retry policy which specifies a maximum wait time of 15 minutes and a 10 sec interval (which is converted to a MaximumCount policy with 15 min / 10 sec = 90 tries). But each NMProxy retry policy invokes o.a.h.ipc.Client's retry policy: {noformat}      if (connectionRetryPolicy == null) {
        final int max = conf.getInt(
            CommonConfigurationKeysPublic.IPC_CLIENT_CONNECT_MAX_RETRIES_KEY,
            CommonConfigurationKeysPublic.IPC_CLIENT_CONNECT_MAX_RETRIES_DEFAULT);
        final int retryInterval = conf.getInt(
            CommonConfigurationKeysPublic.IPC_CLIENT_CONNECT_RETRY_INTERVAL_KEY,
            CommonConfigurationKeysPublic
                .IPC_CLIENT_CONNECT_RETRY_INTERVAL_DEFAULT);

        connectionRetryPolicy = RetryPolicies.retryUpToMaximumCountWithFixedSleep(
            max, retryInterval, TimeUnit.MILLISECONDS);
      }{noformat}
So the time it takes the NMProxy to fail is actually (90 retries) * (10 sec NMProxy interval + o.a.h.ipc.Client retry time). In the default case, ipc client retries 10 times with a 1 sec interval, meaning the time it takes for NMProxy to fail is (90)(10 sec + 10 sec) = 30 min instead of the 15 min specified by NMProxy configuration.



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