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Naganarasimha G R commented on YARN-3367: ----------------------------------------- Hi [~djp], Can you share your thoughts on why events are required to be in order ? Are you visualizing some erroneous situation *when the sync and async events are out of order ?* My guess would be that, it might impact if async events like resource utilization for a given container should be in order so that aggregation and accumulation are proper, but i was not able to identify any scenario where sync and async events should be in order. If its required then i need to bring in some additional modifications in the patch. > Replace starting a separate thread for post entity with event loop in > TimelineClient > ------------------------------------------------------------------------------------ > > Key: YARN-3367 > URL: https://issues.apache.org/jira/browse/YARN-3367 > Project: Hadoop YARN > Issue Type: Sub-task > Components: timelineserver > Affects Versions: YARN-2928 > Reporter: Junping Du > Assignee: Naganarasimha G R > Attachments: YARN-3367.YARN-2928.001.patch > > > Since YARN-3039, we add loop in TimelineClient to wait for > collectorServiceAddress ready before posting any entity. In consumer of > TimelineClient (like AM), we are starting a new thread for each call to get > rid of potential deadlock in main thread. This way has at least 3 major > defects: > 1. The consumer need some additional code to wrap a thread before calling > putEntities() in TimelineClient. > 2. It cost many thread resources which is unnecessary. > 3. The sequence of events could be out of order because each posting > operation thread get out of waiting loop randomly. > We should have something like event loop in TimelineClient side, > putEntities() only put related entities into a queue of entities and a > separated thread handle to deliver entities in queue to collector via REST > call. -- This message was sent by Atlassian JIRA (v6.3.4#6332)