Documentation Home
MySQL 9.2 Reference Manual
Related Documentation Download this Manual
PDF (US Ltr) - 40.8Mb
PDF (A4) - 40.9Mb
Man Pages (TGZ) - 259.7Kb
Man Pages (Zip) - 366.9Kb
Info (Gzip) - 4.1Mb
Info (Zip) - 4.1Mb


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,node_id denotes either a storage node ID or the keywordALL, which indicates that the command should be applied to all of the cluster's data nodes.

  • CLUSTERLOG ON

    Turns the cluster log on.

  • CLUSTERLOG OFF

    Turns the cluster log off.

  • CLUSTERLOG INFO

    Provides information about cluster log settings.

  • node_id CLUSTERLOGcategory=threshold

    Logscategory events with priority less than or equal tothreshold in the cluster log.

  • CLUSTERLOG TOGGLEseverity_level

    Toggles cluster logging of events of the specifiedseverity_level.

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

CategoryDefault threshold (All data nodes)
STARTUP7
SHUTDOWN7
STATISTICS7
CHECKPOINT7
NODERESTART7
CONNECTION8
ERROR15
INFO7
BACKUP15
CONGESTION7
SCHEMA7

TheSTATISTICS 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, aSTARTUP 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 Unixsyslog levels, except forLOG_EMERG andLOG_NOTICE, which are not used or mapped.

Table 25.27 Event severity levels

Severity Level ValueSeverityDescription
1ALERTA condition that should be corrected immediately, such as a corrupted system database
2CRITICALCritical conditions, such as device errors or insufficient resources
3ERRORConditions that should be corrected, such as configuration errors
4WARNINGConditions that are not errors, but that might require special handling
5INFOInformational messages
6DEBUGDebugging messages used forNDBCLUSTER development

Event severity levels can be turned on or off usingCLUSTERLOG TOGGLE. 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 aCLUSTERLOG command in an instance ofndb_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.