Gabor Bota created HADOOP-15622: ----------------------------------- Summary: UserGroupInformation TGT renewer refreshTime should be based on getNextTgtRenewalTime Key: HADOOP-15622 URL: https://issues.apache.org/jira/browse/HADOOP-15622 Project: Hadoop Common Issue Type: Bug Reporter: Gabor Bota
The calculation of nextRefresh in UserGroupInformation is currently based on: {code:java} nextRefresh = Math.max(getRefreshTime(tgt), now + kerberosMinSecondsBeforeRelogin); {code} Most of the time nextRefresh = getRefreshTime(tgt). If it is renewing exactly on refreshTime, and there are parallel operations using expired ticket. There is a time gap that some operations might not perform until the next tgt is obtained. Ideally, we want to keep service uninterrupted, therefore getNextTgtRenewalTime supposed to calculate the time a few minutes before Kerberos tgt expired to determine the nextRefresh time. It looks like we are not using getNextTgtRenewalTime method to calculate nextRefresh instead opt-in to use ticket expiration time as base line for nextRefresh. I think patch 2 approach can create time gap then strain on KDC server when ticket can not be renewed. It would be better to calculate nextRefresh based on getNextTgtRenewalTime. -- This message was sent by Atlassian JIRA (v7.6.3#76005) --------------------------------------------------------------------- To unsubscribe, e-mail: common-dev-unsubscr...@hadoop.apache.org For additional commands, e-mail: common-dev-h...@hadoop.apache.org