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.
Configuration
Configurable at cluster level. See Configuring the Alarm Threshold Using the CLI for more information.

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.
Configuration
Configurable at cluster level. See Configuring the Alarm Threshold Using the CLI for more information.

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.

VIPAssignment 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.

DARE Enabled

UI Column
DARE Enabled Alarm
Logged As

CLUSTER_ALARM_DARE_COPY_MASTER_KEY

Meaning
Data-at-rest encryption (DARE) is enabled on the cluster.
Resolution
When DARE is enabled on the cluster, a date-at-rest encryption master key file is generated and stored in /opt/mapr/conf/dare.master.key on the CLDB node. Before dismissing the alarm, make a copy of the master key file because loss of the master key file can be catastrophic and irreversible and might result in loss of data.

DARE Incompatible

UI Column
DARE Incompatible Alarm
Logged As
CLUSTER_ALARM_DARE_INCOMPATIBLE
Meaning
Not all nodes on the cluster are enabled for data-at-rest encryption (DARE).
Resolution
When DARE is enabled on certain nodes in the cluster, there may still be some nodes that are not (yet) enabled for DARE. Enable DARE on all the nodes before dismissing the alarm.

Too Many Snapshots

UI Column
Too Many Snapshots
Logged As
CLUSTER_ALARM_TOO_MANY_SNAPSHOT_CONTAINERS
Meaning
There are too many snapshots on this cluster.
Resolution
Delete snapshots from the cluster before dismissing the alarm.