Cluster Alarms

Cluster alarms indicate problems that affect the cluster as a whole. The following sections describe the MapR cluster alarms.

CLDB Low Memory Alarm

UI Column

Cluster freespace above CLDB heapsize

Logged As

CLUSTER_ALARM_CLDB_HEAPSIZE

Meaning

The CLDB process needs more memory to cache containers.

Resolution

The CLDB heap size is no longer sufficient for the CLDB to cache containers. The solution is to increase the CLDB memory settings on all CLDB nodes, using the same value for the minimum and maximum heap sizes. The text the alarm code provides will include the minimum amount of memory required to be sufficient; however, to accommodate future growth, you should set these values to a somewhat higher number. For example, if the alarm indicates that the CLDB needs 4000 MB, you should set the minimum and maximum heap sizes to a larger value such as 4400 MB.

The CLDB memory settings are controlled by the following parameters in the warden.conf file located in $MAPR_HOME/conf/::

service.command.cldb.heapsize.max=<max heap size> service.command.cldb.heapsize.min=<min heap size>

Restart the Warden service on each CLDB node after you edit the warden.conf file.

License Near Expiration

UI Column: License Near Expiration Alarm
Logged As: CLUSTER_ALARM_LICENSE_NEAR_EXPIRATION
Meaning: The Enterprise Edition license associated with the cluster is within 30 days of expiration.
Resolution: Renew the Enterprise Edition license.

License Expired

UI Column: License Expiration Alarm
Logged As: CLUSTER_ALARM_LICENSE_EXPIRED
Meaning: The Enterprise Edition license associated with the cluster has expired. Enterprise Edition features have been disabled.
Resolution: Renew the Enterprise Edition license.

Cluster Almost Full

UI Column: Cluster Almost Full
Logged As: CLUSTER_ALARM_CLUSTER_ALMOST_FULL
Meaning: The cluster storage is almost full. The percentage of storage used before this alarm is triggered is 90% by default, and is controlled by the configuration parameter cldb.cluster.almost.full.percentage.
Resolution: Reduce the amount of data stored in the cluster. If the cluster storage is less than 90% full, check the cldb.cluster.almost.full.percentage parameter via the config load command, and adjust it if necessary via the config save command.

Cluster Full

UI Column: Cluster Full
Logged As: CLUSTER_ALARM_CLUSTER_FULL
Meaning: The cluster storage is full. MapReduce operations have been halted.
Resolution: Free up some space on the cluster.

Maximum Licensed Nodes Exceeded alarm

UI Column: Licensed Nodes Exceeded Alarm
Logged As: CLUSTER_ALARM_LICENSE_MAXNODES_EXCEEDED
Meaning: The cluster has exceeded the number of nodes specified in the license.
Resolution: Remove some nodes, or upgrade the license to accommodate the added nodes.

New Cluster Features Disabled

UI Column: New Cluster Features Disabled
Logged As: CLUSTER_ALARM_NEW_FEATURES_DISABLED
Meaning: Features added in version 2.0 or 3.0 are not enabled on the cluster.
Resolution: Enable the latest features for the version of MapR that you are currently running.

Upgrade in Progress

UI Column: Software Installation & Upgrades
Logged As: CLUSTER_ALARM_UPGRADE_IN_PROGRESS
Meaning: A rolling upgrade of the cluster is in progress.
Resolution: No action is required. Performance may be affected during the upgrade, but the cluster should still function normally. After the upgrade is complete, the alarm is cleared.

VIP Assignment Failure

UI Column: VIP Assignment Alarm
Logged As: CLUSTER_ALARM_UNASSIGNED_VIRTUAL_IPS
Meaning: MapR was unable to assign a VIP to any NFS servers.
Resolution: Check the VIP configuration, and make sure at least one of the NFS servers in the VIP pool are up and running. See Setting Up VIPs for NFS. This alarm can also indicate that a VIP's hostname exceeds the maximum allowed length of 16. Check the log file /opt/mapr/logs/nfsmon.log for additional information.