Troubleshooting Initialization

Difficulty bringing up the cluster seems daunting, but most cluster problems are easily resolved. For the latest support tips, visit http://answers.mapr.com.

  • Can each node connect with the others? For a list of ports that must be open, see Ports Used by MapR.

  • Is the warden 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 MFS 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:

      /etc/sudoers

      Allows the mapr user to invoke commands as root

      /etc/security/limits.conf

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

      /etc/udev/rules.d/99-mapr-disk.rules

      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.