Troubleshooting Installation

If you are having difficulty bringing up the cluster, you have a number of options.

Difficulty bringing up the cluster seems daunting, but most cluster problems are easily resolved. For the latest support tips, visit the MapR Converge Community.

  • Can each node connect with the others? For a list of ports that must be open, see Ports Used by MapR.
  • Is the Warden service running on each node? On the node, run the following command as root:

    $ service mapr-warden status
    WARDEN running as process 18732

    If the Warden service is not running, check the Warden log file, /opt/mapr/logs/warden.log, for clues. To restart the Warden service:

    $ service mapr-warden start
  • The ZooKeeper service is not running on one or more nodes:
    • Check the Warden log file for errors related to resources, such as low memory
    • Check the Warden log file for errors related to user permissions
    • Check for DNS and other connectivity issues between ZooKeeper nodes
  • The MapR CLI program /opt/mapr/bin/maprcli won't run
  • Instance Mismatch Node Alarm is raised
    • Restart Warden to ensure that the number of MapR Filesystem instances is as configured.
  • Permission errors appear in the log
    • Check that MapR changes to the following files have not been overwritten by automated configuration management tools:


      Allows the mapr user to invoke commands as root


      Allows MapR services to increase limits on resources such as memory, file handles, threads and processes, and maximum priority level


      Covers permissions and ownership of raw disk devices

Before contacting MapR Support, you can collect your cluster's logs using the mapr-support-collect script.