gpperfmon Database Reference

gpperfmon Database Reference

The gpperfmon database is a dedicated database where data collection agents on Greenplum segment hosts save statistics. The optional Greenplum Command Center management tool requires the database.

The gpperfmon database is created using the gpperfmon_install command-line utility, which creates the database and the gpmon database role and enables monitoring agents on the Greenplum hosts. See the gpperfmon_install reference in the Greenplum Database Utility Guide for information about using the utility and configuring the data collection agents.

The tables in the gpperfmon database consist of three sets of tables.

  • now tables store data on current system metrics such as active queries.
  • history tables store data on historical metrics.
  • tail tables are for data in transition. Tail tables are for internal use only and should not be queried by users. The now and tail data are stored as text files on the master host file system, and accessed by the Command Center database via external tables. The history tables are regular database tables stored within the Command Center (gpperfmon) database.

The database contains the following categories of tables:

  • The database_* tables store query workload information for a Greenplum Database instance.
  • The diskspace_* tables store diskspace metrics.
  • The emcconnect_history table displays information about ConnectEMC events and alerts. ConnectEMC events are triggered based on a hardware failure, a fix to a failed hardware component, or a Greenplum Database startup. Once an ConnectEMC event is triggered, an alert is sent to EMC Support. (Deprecated)
  • The filerep_* tables store health and status metrics for the file replication process. This process is how high-availability/mirroring is achieved in Greenplum Database instance. Statistics are maintained for each primary-mirror pair.
  • The iterators_* tables store information about query plan iterators and their metrics. A query iterator refers to a node or operation in a query plan. (Deprecated)
  • The log_alert_* tables store information about pg_log errors and warnings.
  • The network_interface_* tables store statistical metrics for each active interface of a Greenplum Database instance. These tables are not currently populated and are deprecated. They will be removed in a future release.
  • The queries_* tables store high-level query status information.
  • The segment_* tables store memory allocation statistics for the Greenplum Database segment instances.
  • The socket_* tables store statistical metrics about socket usage for a Greenplum Database instance. These tables are not currently populated and are deprecated. They will be removed in a future release.
  • The system_* tables store system utilization metrics.
  • The tcp_* tables store statistical metrics about TCP communications for a Greenplum Database instance. Note: These tables are not currently populated and are deprecated. They will be removed in a future release.
  • The udp_* tables store statistical metrics about UDP communications for a Greenplum Database instance. Note: These tables are not currently populated and are deprecated. They will be removed in a future release.

The Command Center database also contains the following views:

  • The dynamic_memory_info view shows an aggregate of all the segments per host and the amount of dynamic memory used per host.
  • The iterators_*_rollup set of views summarize the query iterator metrics across all segments in the system. (Deprecated)
  • The memory_info view shows per-host memory information from the system_history and segment_history tables.