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Jian He commented on YARN-4497: ------------------------------- [~hex108], thanks for working on this. for the patch, I think making below change in RMAppImpl#recover may be enough ? {code} - for(int i=0; i<appState.getAttemptCount(); ++i) { - // create attempt - createNewAttempt(); + + for (ApplicationAttemptId attemptId: appState.attempts.keySet()) { + createNewAttempt(attemptId); ((RMAppAttemptImpl)this.currentAttempt).recover(state); {code} > RM might fail to restart when recovering apps whose attempts are missing > ------------------------------------------------------------------------ > > Key: YARN-4497 > URL: https://issues.apache.org/jira/browse/YARN-4497 > Project: Hadoop YARN > Issue Type: Bug > Reporter: Jun Gong > Assignee: Jun Gong > Priority: Critical > Attachments: YARN-4497.01.patch > > > Find following problem when discussing in YARN-3480. > If RM fails to store some attempts in RMStateStore, there will be missing > attempts in RMStateStore, for the case storing attempt1, attempt2 and > attempt3, RM successfully stored attempt1 and attempt3, but failed to store > attempt2. When RM restarts, in *RMAppImpl#recover*, we recover attempts one > by one, for this case, we will recover attmept1, then attempt2. When > recovering attempt2, we call > *((RMAppAttemptImpl)this.currentAttempt).recover(state)*, it will first find > its ApplicationAttemptStateData, but it could not find it, an error will come > at *assert attemptState != null*(*RMAppAttemptImpl#recover*, line 880). -- This message was sent by Atlassian JIRA (v6.3.4#6332)