Cloudera Docs

Switching from CMS to G1GC

To move from Concurrent Mark Sweep (CMS) GC to Garbage First (G1) GC, you must update the Java Configuration Options for NameNode settings in the HDFS configurations in Cloudera Manager.

  1. Sign in to Cloudera Manager.
  2. In the left navigation, click Clusters.
  3. Select the HDFS cluster and click Configuration.
  4. Search for Java Configuration Options for NameNode.
  5. Remove the {{JAVA_GC_ARGS}} value in the text box and add the required -XX options:
    • -XX:+UseG1GC
    • (Optional) -XX:MaxGCPauseMillis=####
    • (Optional) Add -XX:InitiatingHeapOccupancyPercent=####
    • (Optional) Add -XX:ParallelGCThreads=####