[ https://issues.apache.org/jira/browse/SPARK-21829?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Apache Spark reassigned SPARK-21829: ------------------------------------ Assignee: Apache Spark > Enable config to permanently blacklist a list of nodes > ------------------------------------------------------ > > Key: SPARK-21829 > URL: https://issues.apache.org/jira/browse/SPARK-21829 > Project: Spark > Issue Type: New Feature > Components: Scheduler, Spark Core > Affects Versions: 2.1.1, 2.2.0 > Reporter: Luca Canali > Assignee: Apache Spark > Priority: Minor > > The idea for this proposal comes from a performance incident in a local > cluster where a job was found very slow because of a log tail of stragglers > due to 2 nodes in the cluster being slow to access a remote filesystem. > The issue was limited to the 2 machines and was related to external > configurations: the 2 machines that performed badly when accessing the remote > file system were behaving normally for other jobs in the cluster (a shared > YARN cluster). > With this new feature I propose to introduce a mechanism to allow users to > specify a list of nodes in the cluster where executors/tasks should not run > for a specific job. > The proposed implementation that I tested (see PR) uses the Spark blacklist > mechanism. With the parameter spark.blacklist.alwaysBlacklistedNodes, a list > of user-specified nodes is added to the blacklist at the start of the Spark > Context and it is never expired. > I have tested this on a YARN cluster on a case taken from the original > production problem and I confirm a performance improvement of about 5x for > the specific test case I have. I imagine that there can be other cases where > Spark users may want to blacklist a set of nodes. This can be used for > troubleshooting, including cases where certain nodes/executors are slow for a > given workload and this is caused by external agents, so the anomaly is not > picked up by the cluster manager. -- This message was sent by Atlassian JIRA (v6.4.14#64029) --------------------------------------------------------------------- To unsubscribe, e-mail: issues-unsubscr...@spark.apache.org For additional commands, e-mail: issues-h...@spark.apache.org