25.6.3.1 NDB Cluster Logging Management Commands (original) (raw)

25.6.3.1 NDB Cluster Logging Management Commands

ndb_mgm supports a number of management commands related to the cluster log and node logs. In the listing that follows, nodeid denotes either a storage node ID or the keyword ALL, which indicates that the command should be applied to all of the cluster's data nodes.

The following table describes the default setting (for all data nodes) of the cluster log category threshold. If an event has a priority with a value lower than or equal to the priority threshold, it is reported in the cluster log.

Note

Events are reported per data node, and that the threshold can be set to different values on different nodes.

Table 25.26 Cluster log categories, with default threshold setting

Category Default threshold (All data nodes)
STARTUP 7
SHUTDOWN 7
STATISTICS 7
CHECKPOINT 7
NODERESTART 7
CONNECTION 8
ERROR 15
INFO 7
BACKUP 15
CONGESTION 7
SCHEMA 7

The STATISTICS category can provide a great deal of useful data. SeeSection 25.6.3.3, “Using CLUSTERLOG STATISTICS in the NDB Cluster Management Client”, for more information.

Thresholds are used to filter events within each category. For example, a STARTUP event with a priority of 3 is not logged unless the threshold forSTARTUP is set to 3 or higher. Only events with priority 3 or lower are sent if the threshold is 3.

The following table shows the event severity levels.

Note

These correspond to Unix syslog levels, except for LOG_EMERG andLOG_NOTICE, which are not used or mapped.

Table 25.27 Event severity levels

Severity Level Value Severity Description
1 ALERT A condition that should be corrected immediately, such as a corrupted system database
2 CRITICAL Critical conditions, such as device errors or insufficient resources
3 ERROR Conditions that should be corrected, such as configuration errors
4 WARNING Conditions that are not errors, but that might require special handling
5 INFO Informational messages
6 DEBUG Debugging messages used for NDBCLUSTER development

Event severity levels can be turned on or off (usingCLUSTERLOG FILTER—see above). If a severity level is turned on, then all events with a priority less than or equal to the category thresholds are logged. If the severity level is turned off then no events belonging to that severity level are logged.

Important

Cluster log levels are set on a perndb_mgmd, per subscriber basis. This means that, in an NDB Cluster with multiple management servers, using a CLUSTERLOG command in an instance of ndb_mgm connected to one management server affects only logs generated by that management server but not by any of the others. This also means that, should one of the management servers be restarted, only logs generated by that management server are affected by the resetting of log levels caused by the restart.