[ https://issues.apache.org/jira/browse/SPARK-31028?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
shanyu zhao updated SPARK-31028: -------------------------------- Description: When starting Spark driver and executors on Yarn cluster, the JVM process can discover all CPU cores on the system and set thread-pool or GC threads based on that value. We should limit what the JVM sees for the number of cores set by the user (spark.driver.cores or spark.executor.cores) by "-XX:ActiveProcessorCount", which was introduced in Java 8u191. Especially in running Spark on Yarn inside Kubernetes container, the number of CPU cores discovered sometimes is 1, which means it always use 1 thread in the default thread pool, or GC threads. was:When starting Spark driver and executors on Yarn cluster, the JVM process can discover all CPU cores on the system and set thread-pool or GC threads based on that value. We should limit what the JVM sees for the number of cores set by the user (spark.driver.cores or spark.executor.cores) by "-XX:ActiveProcessorCount", which was introduced in Java 8u191. > Add "-XX:ActiveProcessorCount" to Spark driver and executor in Yarn mode > ------------------------------------------------------------------------ > > Key: SPARK-31028 > URL: https://issues.apache.org/jira/browse/SPARK-31028 > Project: Spark > Issue Type: Bug > Components: YARN > Affects Versions: 2.4.5 > Reporter: shanyu zhao > Priority: Major > > When starting Spark driver and executors on Yarn cluster, the JVM process can > discover all CPU cores on the system and set thread-pool or GC threads based > on that value. We should limit what the JVM sees for the number of cores set > by the user (spark.driver.cores or spark.executor.cores) by > "-XX:ActiveProcessorCount", which was introduced in Java 8u191. > Especially in running Spark on Yarn inside Kubernetes container, the number > of CPU cores discovered sometimes is 1, which means it always use 1 thread in > the default thread pool, or GC threads. -- This message was sent by Atlassian Jira (v8.3.4#803005) --------------------------------------------------------------------- To unsubscribe, e-mail: issues-unsubscr...@spark.apache.org For additional commands, e-mail: issues-h...@spark.apache.org