Greenplum Command Center helps administrators and developers measure the
query and system performance metrics for DCA. It integrates HD, database, and
chorus components and provides a single shot view into the health of the system.
To monitor the performance of the appliance, there are performance agents that run
on the master and the segment servers. The agents collect performance data on
query execution and system utilization and send it to dedicated command center
database ( gpperfmon ) at regular intervals. This database is located on the master
server and contains three types of tables: now, history, and tail. Master agent polls
all segment agents for system metrics and other data at a configurable interval and
stores it in flat files and periodically commits the data to the database. Greenplum
Database installation includes setup scripts to install the Command Center data-
base. Now tables store data on current system metrics such as active queries, his-
tory tables store data on historical metrics, and tail tables are for data in transition.
Tail tables are for internal use only. Now and tail data are stored as text files on the
master host file system and accessed by the Command Center database via extern-
al tables. The history tables are regular database tables.
The following functions can be executed from the Command Center:
• Database administration : Ability to stop/start the database and ability to re-
• Interactive view of system metrics : Real-time and historic (configurable by
• Database query monitoring : Ability to view, search, or cancel queries in the
system, and ability to view the query plan
• Database workload : Ability to configure resource queues and ability to pri-
Have a look at the following screenshot: