Greenplum Database Server Configuration Parameters

Greenplum Database gpperfmon Database

The following Greenplum Database configuration parameters must be uncommented and set in the server configuration file (postgresql.conf) to enable the Command Center data collection agents:

  • gp_enable_gpperfmon and gpperfmon_port must be set in both the master and segment postgresql.conf files.
  • gp_enable_gpperfmon and gp_enable_gpperfmon only need to be set in the master postgresql.conf file.

After changing these settings, the Greenplum Database instance must be restarted for the changes to take effect.

gp_enable_gpperfmon
Turns on the Command Center data collection agent for a segment. Must be set in all postgresql.conf files (master and all segments).

gpperfmon_port
The default port for the Command Center agents is 8888, but you can set this parameter to a different port if required (master and all segments).

gp_gpperfmon_send_interval
Sets the frequency in seconds that the Greenplum Database server processes send query execution updates to the Command Center agent processes.

gp_external_enable_exec
This parameter is enabled by default and must remain enabled. It allows the use of external tables that execute OS commands or scripts on the segment hosts. The Command Center agents use this type of external tables to collect current system metrics from the segments.

gpperfmon_log_alert_level
Controls which message levels are written to the gpperfmon log. Each level includes all the levels that follow it. The later the level, the fewer messages are sent to the log. The default value is warning.

shared_preload_libraries
A comma-separated list of shared libraries that are to be preloaded when Greenplum Database starts. The workload management and query metrics extension libraries must be included in this configuration parameter to use Greenplum Command Center.

gp_enable_query_metrics
When on, enables query metrics collection. The default is off. After setting this configuration parameter, Greenplum Database must be restarted for the change to take effect.

gp_instrument_shmem_size
The amount of shared memory, in kilobytes, allocated for query metrics. The default is 5120 and the maximum is 131072. At startup, if gp_enable_query_metrics is set to on, Greenplum Database allocates space in shared memory to save query metrics. This memory is organized as a header and a list of slots. The number of slots needed depends on the number of concurrent queries and the number of execution plan nodes per query. The default value, 5120, is based on a Greenplum Database system that executes a maximum of about 250 concurrent queries with 120 nodes per query. If the gp_enable_query_metrics configuration parameter is off, or if the slots are exhausted, the metrics are maintained in local memory instead of in shared memory.