[Feature Request] we should print detail reason why the parent task cancelled

[kkewwei]

Is your feature request related to a problem? Please describe

version: Opensearch2.9

In product, we see many TaskCancelledExceptions as follows, but I can't find why the parent task was cancelled:

[2024-01-05T17:06:29,500+0800][ERROR][o.o.b.OpenSearchUncaughtExceptionHandler] [master0] uncaught exception in thread [opensearch[node0][search][T#3]]
org.opensearch.tasks.TaskCancelledException: The parent task was cancelled, shouldn't start any child tasks
        at org.opensearch.tasks.TaskManager$CancellableTaskHolder.registerChildNode(TaskManager.java:666) ~[opensearch-2.9.0.jar:2.9.0]
        at org.opensearch.tasks.TaskManager.registerChildNode(TaskManager.java:345) ~[opensearch-2.9.0.jar:2.9.0]
        at org.opensearch.action.support.TransportAction.registerChildNode(TransportAction.java:76) ~[opensearch-2.9.0.jar:2.9.0]
        at org.opensearch.action.support.TransportAction.execute(TransportAction.java:95) ~[opensearch-2.9.0.jar:2.9.0]
        at org.opensearch.client.node.NodeClient.executeLocally(NodeClient.java:110) ~[opensearch-2.9.0.jar:2.9.0]
        at org.opensearch.client.node.NodeClient.doExecute(NodeClient.java:97) ~[opensearch-2.9.0.jar:2.9.0]
        at org.opensearch.client.support.AbstractClient.execute(AbstractClient.java:476) ~[opensearch-2.9.0.jar:2.9.0]
        at org.opensearch.client.support.AbstractClient.search(AbstractClient.java:607) ~[opensearch-2.9.0.jar:2.9.0]
        at org.opensearch.action.search.TransportMultiSearchAction.executeSearch(TransportMultiSearchAction.java:180) ~[opensearch-2.9.0.jar:2.9.0]
        at org.opensearch.action.search.TransportMultiSearchAction$1.handleResponse(TransportMultiSearchAction.java:203) ~[opensearch-2.9.0.jar:2.9.0]
        at org.opensearch.action.search.TransportMultiSearchAction$1.onFailure(TransportMultiSearchAction.java:188) ~[opensearch-2.9.0.jar:2.9.0]
        at org.opensearch.action.support.TransportAction$1.onFailure(TransportAction.java:122) ~[opensearch-2.9.0.jar:2.9.0]
        at org.opensearch.action.ActionListener$1.onFailure(ActionListener.java:88) ~[opensearch-2.9.0.jar:2.9.0]
        at org.opensearch.action.ActionListener$5.onFailure(ActionListener.java:275) ~[opensearch-2.9.0.jar:2.9.0]
        at org.opensearch.action.search.AbstractSearchAsyncAction.raisePhaseFailure(AbstractSearchAsyncAction.java:691) ~[opensearch-2.9.0.jar:2.9.0]
        at org.opensearch.action.search.AbstractSearchAsyncAction.onPhaseFailure(AbstractSearchAsyncAction.java:665) ~[opensearch-2.9.0.jar:2.9.0]
        at org.opensearch.action.search.FetchSearchPhase$1.onFailure(FetchSearchPhase.java:128) ~[opensearch-2.9.0.jar:2.9.0]
        at org.opensearch.common.util.concurrent.AbstractRunnable.run(AbstractRunnable.java:54) ~[opensearch-2.9.0.jar:2.9.0]
        at org.opensearch.threadpool.TaskAwareRunnable.doRun(TaskAwareRunnable.java:78) ~[opensearch-2.9.0.jar:2.9.0]
        at org.opensearch.common.util.concurrent.AbstractRunnable.run(AbstractRunnable.java:52) ~[opensearch-2.9.0.jar:2.9.0]
        at org.opensearch.common.util.concurrent.TimedRunnable.doRun(TimedRunnable.java:59) ~[opensearch-2.9.0.jar:2.9.0]
        at org.opensearch.common.util.concurrent.ThreadContext$ContextPreservingAbstractRunnable.doRun(ThreadContext.java:908) ~[opensearch-2.9.0.jar:2.9.0]
        at org.opensearch.common.util.concurrent.AbstractRunnable.run(AbstractRunnable.java:52) ~[opensearch-2.9.0.jar:2.9.0]
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1136) ~[?:?]
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:635) ~[?:?]
        at java.lang.Thread.run(Thread.java:833) [?:?]

if we can also print the reason why the parent task cancelled.

Related component

Search

[peternied]

[Triage - attendees 1 2]
@kkewwei Thanks for filing, looking forward to pull request to include these details on cancelation.