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Posted to yarn-issues@hadoop.apache.org by "ASF GitHub Bot (Jira)" <ji...@apache.org> on 2022/12/22 11:48:00 UTC

[jira] [Commented] (YARN-11178) Avoid CPU busy idling and resource wasting in DelegationTokenRenewerPoolTracker thread

    [ https://issues.apache.org/jira/browse/YARN-11178?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17651248#comment-17651248 ] 

ASF GitHub Bot commented on YARN-11178:
---------------------------------------

slfan1989 commented on PR #4435:
URL: https://github.com/apache/hadoop/pull/4435#issuecomment-1362744741

   @LennonChin can we rebase again?




> Avoid CPU busy idling and resource wasting in DelegationTokenRenewerPoolTracker thread
> --------------------------------------------------------------------------------------
>
>                 Key: YARN-11178
>                 URL: https://issues.apache.org/jira/browse/YARN-11178
>             Project: Hadoop YARN
>          Issue Type: Bug
>          Components: resourcemanager, security
>    Affects Versions: 3.3.1, 3.3.2, 3.3.3, 3.3.4
>         Environment: Hadoop 3.3.3 with Kerberos, Ranger 2.1.0, Hive 2.3.7 and Spark 3.0.3
>            Reporter: Lennon Chin
>            Priority: Minor
>              Labels: pull-request-available
>         Attachments: YARN-11178.CPU idling busy 100% before optimized.png, YARN-11178.CPU normal after optimized.png, YARN-11178.CPU profile for idling busy 100% before optimized.html, YARN-11178.CPU profile for idling busy 100% before optimized.png, YARN-11178.CPU profile for normal after optimized.html, YARN-11178.CPU profile for normal after optimized.png
>
>          Time Spent: 1h 40m
>  Remaining Estimate: 0h
>
> The DelegationTokenRenewerPoolTracker thread is busy wasting CPU resource in empty poll iterate when there is no delegation token renewer event task in the futures map:
> {code:java}
> // org.apache.hadoop.yarn.server.resourcemanager.security.DelegationTokenRenewer.DelegationTokenRenewerPoolTracker#run
> @Override
> public void run() {
>   // this while true loop is busy when the `futures` is empty
>   while (true) {
>     for (Map.Entry<DelegationTokenRenewerEvent, Future<?>> entry : futures
>         .entrySet()) {
>       DelegationTokenRenewerEvent evt = entry.getKey();
>       Future<?> future = entry.getValue();
>       try {
>         future.get(tokenRenewerThreadTimeout, TimeUnit.MILLISECONDS);
>       } catch (TimeoutException e) {
>         // Cancel thread and retry the same event in case of timeout
>         if (future != null && !future.isDone() && !future.isCancelled()) {
>           future.cancel(true);
>           futures.remove(evt);
>           if (evt.getAttempt() < tokenRenewerThreadRetryMaxAttempts) {
>             renewalTimer.schedule(
>                 getTimerTask((AbstractDelegationTokenRenewerAppEvent) evt),
>                 tokenRenewerThreadRetryInterval);
>           } else {
>             LOG.info(
>                 "Exhausted max retry attempts {} in token renewer "
>                     + "thread for {}",
>                 tokenRenewerThreadRetryMaxAttempts, evt.getApplicationId());
>           }
>         }
>       } catch (Exception e) {
>         LOG.info("Problem in submitting renew tasks in token renewer "
>             + "thread.", e);
>       }
>     }
>   }
> }{code}
> A better way to avoid CPU idling is waiting for some time when the `futures` map is empty, and when the renewer task done or cancelled, we should remove the task future in `futures` map to avoid memory leak:
> {code:java}
> @Override
> public void run() {
>   while (true) {
>     // waiting for some time when futures map is empty
>     if (futures.isEmpty()) {
>       synchronized (this) {
>         try {
>           // waiting for tokenRenewerThreadTimeout milliseconds
>           long waitingTimeMs = Math.min(10000, Math.max(500, tokenRenewerThreadTimeout));
>           LOG.info("Delegation token renewer pool is empty, waiting for {} ms.", waitingTimeMs);
>           wait(waitingTimeMs);
>         } catch (InterruptedException e) {
>           LOG.warn("Delegation token renewer pool tracker waiting interrupt occurred.");
>           Thread.currentThread().interrupt();
>         }
>       }
>       if (futures.isEmpty()) {
>         continue;
>       }
>     }
>     for (Map.Entry<DelegationTokenRenewerEvent, Future<?>> entry : futures
>         .entrySet()) {
>       DelegationTokenRenewerEvent evt = entry.getKey();
>       Future<?> future = entry.getValue();
>       try {
>         future.get(tokenRenewerThreadTimeout, TimeUnit.MILLISECONDS);
>       } catch (TimeoutException e) {
>         // Cancel thread and retry the same event in case of timeout
>         if (future != null && !future.isDone() && !future.isCancelled()) {
>           future.cancel(true);
>           futures.remove(evt);
>           if (evt.getAttempt() < tokenRenewerThreadRetryMaxAttempts) {
>             renewalTimer.schedule(
>                 getTimerTask((AbstractDelegationTokenRenewerAppEvent) evt),
>                 tokenRenewerThreadRetryInterval);
>           } else {
>             LOG.info(
>                 "Exhausted max retry attempts {} in token renewer "
>                     + "thread for {}",
>                 tokenRenewerThreadRetryMaxAttempts, evt.getApplicationId());
>           }
>         }
>       } catch (Exception e) {
>         LOG.info("Problem in submitting renew tasks in token renewer "
>             + "thread.", e);
>       }
>       // remove done and cancelled task
>       if (future.isDone() || future.isCancelled()) {
>         try {
>           futures.remove(evt);
>           LOG.info("Removed done or cancelled renew tasks of {} in token renewer thread.", evt.getApplicationId());
>         } catch (Exception e) {
>           LOG.warn("Problem in removing done or cancelled renew tasks in token renewer thread.", e);
>         }
>       }
>     }
>   }
> } {code}
>  



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