> On March 18, 2015, 4:14 p.m., Guozhang Wang wrote: > > core/src/main/scala/kafka/server/DelayedOperation.scala, line 373 > > <https://reviews.apache.org/r/31568/diff/1/?file=881353#file881353line373> > > > > Try purging on each watcher list in each doWork will likely increase > > the CPU a lot, we can reduce the CPU usage by only purging when watched() > > is too large.
A list scan happens only when the unreachable count is greater than 100. The unreachable count is incremented by polling the reference queue. So, it is driven by GC cycles in some sense. If there is nothing to purge, the scan won't happen. And it is set to zero when tryCompleteWatched is called. So, I expect that the unreachable count is low most of the time. There is a problem in using watched(). It is the count of watched requests. On a busy server, watched() may exceed the threashold more often even when there is not many entries to purge. - Yasuhiro ----------------------------------------------------------- This is an automatically generated e-mail. To reply, visit: https://reviews.apache.org/r/31568/#review76899 ----------------------------------------------------------- On Feb. 28, 2015, 12:14 a.m., Yasuhiro Matsuda wrote: > > ----------------------------------------------------------- > This is an automatically generated e-mail. To reply, visit: > https://reviews.apache.org/r/31568/ > ----------------------------------------------------------- > > (Updated Feb. 28, 2015, 12:14 a.m.) > > > Review request for kafka. > > > Bugs: KAFKA-1989 > https://issues.apache.org/jira/browse/KAFKA-1989 > > > Repository: kafka > > > Description > ------- > > new purgatory implementation > > > Diffs > ----- > > core/src/main/scala/kafka/server/DelayedOperation.scala > e317676b4dd5bb5ad9770930e694cd7282d5b6d5 > core/src/main/scala/kafka/server/ReplicaManager.scala > 586cf4caa95f58d5b2e6c7429732d25d2b3635c8 > core/src/main/scala/kafka/utils/SinglyLinkedWeakList.scala PRE-CREATION > core/src/main/scala/kafka/utils/timer/Timer.scala PRE-CREATION > core/src/main/scala/kafka/utils/timer/TimerTask.scala PRE-CREATION > core/src/main/scala/kafka/utils/timer/TimerTaskList.scala PRE-CREATION > core/src/main/scala/kafka/utils/timer/TimingWheel.scala PRE-CREATION > core/src/test/scala/unit/kafka/server/DelayedOperationTest.scala > 7a37617395b9e4226853913b8989f42e7301de7c > core/src/test/scala/unit/kafka/utils/timer/TimerTaskListTest.scala > PRE-CREATION > core/src/test/scala/unit/kafka/utils/timer/TimerTest.scala PRE-CREATION > > Diff: https://reviews.apache.org/r/31568/diff/ > > > Testing > ------- > > > Thanks, > > Yasuhiro Matsuda > >
