Data nodes and management servers regularly and on specific occasions report on various log events that occur in the cluster. These log events are written to the cluster log. Optionally an MGM API client may listen to these events using the method ndb_mgm_listen_event(). Each log event belongs to a category ndb_mgm_event_category) and has a severity ndb_mgm_event_severity associated with it. Each log event also has a level (0-15) associated with it.

Which log events that come out is controlled with ndb_mgm_listen_event(), ndb_mgm_set_clusterlog_loglevel(), and ndb_mgm_set_clusterlog_severity_filter().

This is an example showing how to listen to events related to backup:

int filter[] = { 15, NDB_MGM_EVENT_CATEGORY_BACKUP, 0 };
int fd = ndb_mgm_listen_event(handle, filter);