Command Center Agent Parameters

The $MASTER_DATA_DIRECTORY/gpperfmon/conf/gpperfmon.conf file on the Greenplum Database master host stores configuration parameters for the Command Center agents. For configuration changes to these options to take effect, you must save gpperfmon.conf and then restart Greenplum Database server (gpstop -r).

To enable the Command Center agents within Greenplum Database server, you must also set the Greenplum Database Server Configuration Parameters. See the gpperfmon_install reference in the Greenplum Database Utility Guide for details.

log_location

Specifies a directory location for Command Center log files. Default is $MASTER_DATA_DIRECTORY/gpperfmon/logs.

min_query_time

Specifies the minimum query run time in seconds for statistics collection. Command Center logs all queries that run longer than this value in the queries_history table. For queries with shorter run times, no historical data is collected. Defaults to 20 seconds.

If you know that you want to collect data for all queries, you can set this parameter to a low value. Setting the minimum query run time to zero, however, collects data even for the numerous queries run by Command Center itself, creating a large amount of data that may not be useful.

min_detailed_query_time

Specifies the minimum iterator run time in seconds for statistics collection. Command Center logs all iterators that run longer than this value in the iterators_history table. For iterators with shorter run times, no data is collected. Minimum value is 10 seconds.

This parameter’s value must always be equal to, or greater than, the value of min_query_time. Setting min_detailed_query_time higher than min_query_time allows you to log detailed query plan iterator data only for especially complex, long-running queries, while still logging basic query data for shorter queries.

Given the complexity and size of iterator data, you may want to adjust this parameter according to the size of data collected. If the iterators_* tables are growing to excessive size without providing useful information, you can raise the value of this parameter to log iterator detail for fewer queries.

max_log_size

This parameter is not included in gpperfmon.conf, but it may be added to this file for use with Greenplum Command Center.

To prevent the log files from growing to excessive size, you can add the max_log_size parameter to gpperfmon.conf. The value of this parameter is measured in bytes. For example:

max_log_size = 10485760

With this setting, the log files will grow to 10MB before the system rolls over to a new log file.

partition_age

The number of months that Greenplum Command Center statistics data will be retained. The default it is 0, which means we won’t drop any data.

quantum

Specifies the time in seconds between updates from Command Center agents on all segments. Valid values are 10, 15, 20, 30, and 60. Defaults to 15 seconds.

If you prefer a less granular view of performance, or want to collect and analyze minimal amounts of data for system metrics, choose a higher quantum. To collect data more frequently, choose a lower value.

ignore_qexec_packet

When set to true, Greenplum Command Center agents do not collect performance data in the gpperfmon database queries_* tables: rows_out, cpu_elapsed, cpu_currpct, skew_cpu, and skew_rows. The default setting, true, reduces the amount of memory consumed by the gpmmon process. Set this parameter to false if you require this additional performance data.

smdw_aliases

This parameter allows you to specify additional host names for the standby master. For example, if the standby master has two NICs, you can enter:

smdw_aliases= smdw-1,smdw-2

This optional fault tolerance parameter is useful if the Greenplum Command Center loses connectivity with the standby master. Instead of continuously retrying to connect to host smdw, it will try to connect to the NIC-based aliases of smdw-1 and/or smdw-2. This ensures that the Command Center Console can continuously poll and monitor the standby master.