[ https://issues.apache.org/jira/browse/HDFS-7501?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Stephen Chu reassigned HDFS-7501: --------------------------------- Assignee: Stephen Chu > TransactionsSinceLastCheckpoint can be negative on SBNs > ------------------------------------------------------- > > Key: HDFS-7501 > URL: https://issues.apache.org/jira/browse/HDFS-7501 > Project: Hadoop HDFS > Issue Type: Bug > Components: namenode > Affects Versions: 2.5.0 > Reporter: Harsh J > Assignee: Stephen Chu > Priority: Trivial > > The metric TransactionsSinceLastCheckpoint is derived as FSEditLog.txid minus > NNStorage.mostRecentCheckpointTxId. > In Standby mode, the former does not increment beyond the loaded or > last-when-active value, but the latter does change due to checkpoints done > regularly in this mode. Thereby, the SBN will eventually end up showing > negative values for TransactionsSinceLastCheckpoint. > This is not an issue as the metric only makes sense to be monitored on the > Active NameNode, but we should perhaps just show the value 0 by detecting if > the NN is in SBN form, as allowing a negative number is confusing to view > within a chart that tracks it. -- This message was sent by Atlassian JIRA (v6.3.4#6332)