Creating the gpperfmon Database
This topic describes how to create the Command Center gpperfmon
database and enable the data collection agents. This task must be completed one time for the Greenplum Database system, before you create a Greenplum Command Center instance.
When the data collection agents are enabled, their processes are started and stopped (using gpstart
and gpstop
) on the Greenplum segment hosts along with the Greenplum Database server processes.
Greenplum provides a gpperfmon_install
utility that performs the following tasks:
- Creates the Command Center database (gpperfmon).
- Creates the Command Center superuser role (
gpmon
). - Configures Greenplum Database server to accept connections from the
gpmon
role (edits thepg_hba.conf
and.pgpass
files). - Sets the Command Center server configuration parameters in the Greenplum Database server
postgresql.conf
files.
The gpperfmon_install
utility and the agents are part of the Greenplum Database software. The tasks in this topic can be performed before or after the Command Center software is installed.
Enabling the Collection Agents
Log in to the Greenplum master host as the
gpadmin
user.$ su - gpadmin
Source the path file from the Greenplum Database installation directory:
# source /usr/local/greenplum-db/greenplum_path.sh
Run the
gpperfmon_install
utility with the--enable
option. You must supply the connection port of the Greenplum Database master server process, and set the password for thegpmon
superuser that will be created. For example:$ gpperfmon_install --enable --password changeme --port 5432
Note:
Thegpperfmon_install
utility creates entries for thegpmon
user in the$MASTER_DATABASE/pg_hba.conf
file. See gpmon User Authentication for notes about restricting the gpmon user’s access to databases.The password you specify is saved in a
.pgpass
file in thegpadmin
user’s home directory. See Changing the gpmon Password for steps to change thegpmon
password.When the utility completes, restart Greenplum Database server. The data collection agents do not start until the database is restarted.
$ gpstop -r
Using the
ps
command, verify that the data collection process is running on the Greenplum master. For example:$ ps -ef | grep gpmmon
Run the following command to verify that the
gpmon
user can authenticate and that the data collection processes are writing to the Command Center database. If all of the segment data collection agents are running, you should see one row per segment host.$ psql -U gpmon gpperfmon -c 'SELECT * FROM system_now;'
The data collection agents are now running, and your Greenplum system now has a gpperfmon database installed. This is the database where Command Center data is stored. You can connect to it as follows:
$ psql gpperfmon
Configuring a Standby Master Host (if enabled)
- Copy the
$MASTER_DATA_DIRECTORY/pg_hba.conf
file from your primary master host to your standby master host. This ensures that the required connection options are also set on the standby master. - Copy your
~/.pgpass
file from your primary master host to your standby master host. This file usually resides in thegpadmin
user’s home directory. Note that the permissions on.pgpass
must be set to 600 (for example:chmod 0600 ~/.pgpass
).
gpmon User Authentication
The gperfmon_install
utility adds the gpmon
user to the pg_hba.conf
authorization configuration file entries allowing local connections to any database in the Greenplum cluster. Greenplum Command Center requires that the gpmon
user have access to gpperfmon
and every database that Command Center will monitor. Since the gpmon
role is a Greenplum Database superuser, you may wish to restrict the role from accessing other databases. Edit the $MASTER_DATA_DIRECTORY/pg_hba.conf
and edit these lines:
local gpperfmon gpmon md5
host all gpmon 127.0.0.1/28 md5
host all gpmon ::1/128 md5
List gpperfmon
and the databases you want to monitor with Command Center in the second field:
local gpperfmon,userdb1,userdb2 gpmon md5
host gpperfmon,userdb1,userdb2 gpmon 127.0.0.1/28 md5
host gpperfmon,userdb1,userdb2 gpmon ::1/128 md5
See Changing the gpmon Password for steps to change the gpmon
user’s password.