Setting Up Greenplum Command Center

1.  First you must create the Greenplum Command Center database and enable Greenplum Command Center data collection agents within your Greenplum system.

2.  After data collection is enabled, the next (optional) step is to install and configure the Greenplum Command Center Console (the Web application used to view the Command Center data stored in Greenplum Database).

The Greenplum Database software version of Greenplum Command Center Console is shipped separately from your Greenplum Database installation. Download the installer file from the EMC Download Center. Installer files are available for RedHat 64-bit or SuSE Linux 64 bit platforms.

The Greenplum Data Computing Appliance (DCA) version of the Greenplum Command Center is already installed on the appliance. EMC Services will work with you to further configure Command Center for your enviroment.

• • Enabling the Command Center Data Collection Agents

  • Installing the Greenplum Command Center Console

  • Querying the Command Center Database

  • Uninstalling Greenplum Command Center

Enabling the Command Center Data Collection Agents

This section describes how to create the Command Center database and enable the Command Center data collection agents. When the data collection agents are enabled, their processes are started and stopped along with the Greenplum Database server processes (using gpstart and gpstop).

Greenplum provides a gpperfmon_install utility that performs the following tasks:

• 1. Creates the Command Center database (gpperfmon).

  2. Creates the Command Center superuser role (gpmon).

  3. Configures Greenplum Database server to accept connections from the Command Center superuser role (edits the pg_hba.conf and .pgpass files).

  4. Sets the Command Center server configuration parameters in the Greenplum Database server postgresql.conf files.

Install the Command Center database and enable Command Center agents

1.Log in to the Greenplum master host as the gpadmin user.

$ su - gpadmin

7.Copy your ~/.pgpass file from your primary master host to your standby master host. This file usually resides in the gpadmin user’s home directory.

Installing the Greenplum Command Center Console

The Command Center Console provides a graphical interface for viewing performance data and for administering certain aspects of your Greenplum system. Normally installed on the Greenplum master host, the console is a web-based user interface accessed through a supported browser.

The Command Center Console is typically installed on the Greenplum Database master host. However, you have the option to install the console on a host different from the master host. Note that this setup incurs a performance penalty due to the numerous database connections the console must open over the network.

If you have multiple Greenplum Database instances, you can create separate Command Center Console instances for each of them. Each separate console instance operates on a unique port and has its own unique configuration options.

The Command Center Console supports for any browsers that have Adobe Flash 9.0 or higher enabled. For example, the following browsers are supported:

• • Internet Explorer for Windows XP and Vista

  • Mozilla Firefox for Windows and Linux

  • Apple’s Safari browser for Macintosh

  • Google’s Chrome

The Command Center Console runs on a lighttpd web server. The default web server port is 28080.

Installing the Command Center Console involves the following high-level tasks:

• 1. Install the Command Center Console — Create the software installation directory.

  2. Set up the Greenplum Command Center Console — Create and configure a Command Center Console instance and its supporting web services.

Install the Command Center Console

If you are installing the Command Center Console on a remote system (that is, not the same system on which you installed Greenplum Database), you must also install Greenplum Database installation binary files on the remote system. After installing the binary files, source greenplum_path.sh, then perform the Console installation steps described below. Note that you do not need to initiate the database. 

1.Download the installer file from the EMC Download Center. Installer files are available for RedHat 64-bit, Solaris 64-bit or SuSE Linux 64 bit platforms.

You do not need to download the installer file if you are installing the console on an EMC Data Computing Appliance; the installer file is already loaded on DCAs.

2.Unzip the installer file where PLATFORM is either RHEL5-x86_64 (RedHat 64-bit), SOL-x86_64 (Solaris 64-bit), or SuSE10-x86_64 (SuSe Linux 64-bit). For example:

# unzip greenplum-cc-web-versionx.x-PLATFORM.zip

3.Launch the installer using bash. For example:

# /bin/bash greenplum-cc-web-versionx.x-PLATFORM.bin

4.Type yes to accept the license agreement.

5.The installer will prompt you to provide an installation path. Press ENTER to accept the default install path:

(/usr/local/greenplum-cc-web-versionx.x)

or enter an absolute path to an install location. You must have write permissions to the location you specify. This location is referred to as $GPPERFMONHOME.

6.If you ran the installer as root, change the ownership of the Console installation directory to the gpadmin user. For example:

# chown -R gpadmin /usr/local/greenplum-cc-web-versionx.x

7.The installation directory contains a gpperfmon_path.sh file with path and environment settings for the Console. You must source this file in your gpadmin user’s startup shell profile (such as .bashrc).

For example, you could add a line similar to the following to your chosen profile files:

source /usr/local/greenplum-cc-web-versionx.x/ \ gpperfmon_path.sh

After editing the chosen profile file, source it as the correct user to make the changes active. For example:

$ source ~/.bashrc

Connecting to the Greenplum Command Center Console

Start the Greenplum Command Center Console by entering:

gpcmdr --start

If you do not specify an instance name, all Command Center Console instances are started. To start a particular instance, you can specify the name of the instance. For example:

gpcmdr --start "instance_name"

After the instance is running, you can open the Command Center Console in a supported browser using the correct hostname and port. For example, to open a Command Center instance running on port 28080 on the local host with SSL, use the following web address:

https://localhost:28080/

If connecting to a Command Center instance using SSL on port 28080, enter:

https://command_center_console_hostname:28080/

At the login prompt, enter the user name and password of a Greenplum role that has been properly configured to allow authentication to Greenplum Command Center (for example, gpmon), then click Login. This opens the Dashboard page of the Command Center Console, which provides a graphical system snapshot and a summary view of active queries. See the Command Center Console online help for more information.

You must be a Greenplum administrator to fully use the Greenplum Command Center Console. Administrators can view information for all queries as well as system metrics, while regular database users can only monitor their own queries.

2.Set up a new Command Center Console instance on the standby master host using the instructions in “Setting up the Command Center Console” . 

During the setup process, make sure to specify the following options specific to the standby master:

• • Specify a different instance name than the console instance running on the primary master host.

  • When prompted for the Greenplum Command Center port, specify the same value as the primary master (the standby master must always use the same port as the primary).

  • If you configured the Greenplum Command Center Console for SSL connections, make sure the ssl.pemfile parameter in the web server configuration file points to a valid certificate for the standby master host. You cannot use the same certificate file as the primary master host.

3.If you fail over to your standby master host, the data collection agents are restarted automatically upon activation of the standby. However, you must manually start the Command Center Console using gpcmdr --start.

About the Command Center Installation

The installation and setup procedures create a software installation directory and a directory containing files and folders to support each Greenplum Command Center Console instance.

Software Installation Directory

The following files and first-level subdirectories are copied into the installation folder that you specified when you installed Greenplum Command Center Console. This location is referred to as $GPPERFMONHOME.

• • gpperfmon_path.sh — file containing environment variables for Command Center

  • bin — program files for Greenplum Command Center

  • etc — contains openssl.conf file

  • ext — Python directory and files

  • instances — contains a subdirectory of resources for each Greenplum Database instance monitored by the console

  • lib — library files for Greenplum Command Center

  • www — web service and user interface files

Instances Directory

The $GPPERFMONHOME/instances directory contains subdirectories named for each instance created during console setup. The conf subdirectory contains configuration files that you can edit. Other files and folders are used by the web services for the instance, and should not be modified or deleted.

Each subdirectory contains the following files and first-level subdirectories:

• • lighttpd.pid -- file containing an updated process ID for the web server process for the instance

  • conf — console and web server configuration files, gpperfmonui.conf and lighttpd.conf

  • logs — logs for the web server for this instance

  • perfmon.fastcgi.socket-0 — dynamically updated socket information, which cannot be viewed or updated

  • sessions — files storing information about session state

  • tmp — temporary files used by the web server

  • web — symbolic links to web server files in the installation directory

Querying the Command Center Database

Greenplum Command Center database stores system, query, health, disk space, and dial-home data collected by Command Center agents that run on the master host and each segment (either Hadoop or database) host. This information provides immediate visibility into key areas affecting database performance, and is typically accessed through the Greenplum Command Center Console.

However, you can also use direct SQL queries and views on Command Center data. Before performing any of the tasks in this section, make sure the Greenplum Command Center is completely installed and configured, as described in “Installing the Greenplum Command Center Console” , and “Setting up the Command Center Console” Section.

Viewing Historical System Metrics using SQL

Historical tables in the Command Center database store all system data collected by Command Center. You can analyze this data to identify trends in the performance of the Greenplum system over time.

With a default quantum setting of 15 seconds, Command Center collects very large amounts of historical system data. To view meaningful groupings of system data records, you can view the data by selected time intervals with a SQL view (as described below).

The following provides an example SQL view for viewing aggregated system metrics. In this example view named system_metrics_aggregate_1min, rows of system metrics from system_history are averaged over one-minute intervals and aggregated across all segments in the array:

DROP VIEW IF EXISTS system_metrics_aggregate_1min;

CREATE VIEW system_metrics_aggregate_1min AS (

SELECT date_trunc('minute', ctime) AS sample_time, hostname, avg(mem_total) AS mem_total,

avg(mem_used) AS mem_used,

avg(mem_actual_used) AS mem_actual_used,

avg(mem_actual_free) AS mem_actual_free,

avg(swap_total) AS swap_total, avg(swap_used) AS swap_used, avg(swap_page_in) AS swap_page_in,

avg(swap_page_out) AS swap_page_out,

avg(cpu_user) AS cpu_user, avg(cpu_sys) AS cpu_sys, avg(cpu_idle) AS cpu_idle,

avg(load0) AS load0, avg(load1) AS load1,

avg(load2) AS load2,

Querying the Command Center Database 17

Greenplum Command Center Administrator Guide 1.2 – Chapter 2: Setting Up Greenplum Command Center

avg(disk_ro_rate) AS disk_ro_rate,

avg(disk_wo_rate) AS disk_wo_rate,

avg(disk_rb_rate) AS disk_rb_rate,

avg(disk_wb_rate) AS disk_wb_rate,

avg(net_rp_rate) AS net_rp_rate,

avg(net_wp_rate) AS net_wp_rate,

avg(net_rb_rate) AS net_rb_rate,

avg(net_wb_rate) AS net_wb_rate

FROM system_history

GROUP BY hostname, sample_time

);

To change the interval for averaging results, adjust the value specified for date_trunc. Valid values are microseconds, milliseconds, second, minute, hour, day, week, month, quarter, year, decade, century and millennium.

Note: You use can also the Command Center Console to view historical system metrics. See the Command Center Console online help for more information.

Viewing Historical Query Metrics using SQL

Historical tables in the Command Center database store all query and iterator data collected by Command Center. You can analyze this data to identify trends in the performance of Greenplum system over time.

Calculating the average, minimum and maximum values for system-wide query statistics aggregated over time can yield a useful view of database utilization. The following information provides an example SQL view for viewing query statistics in this way.

In this example view named database_metrics_1hour, rows of statistics from the table database_history are averaged over hour-long intervals:

DROP VIEW if exists database_metrics_1hour;

CREATE VIEW database_metrics_1hour AS (

SELECT date_trunc('hour', ctime) AS sample_time, avg(queries_total) AS queries_total,

min(queries_total) AS queries_total_min,

max(queries_total) AS queries_total_max, avg(queries_running) AS queries_running, min(queries_running) AS queries_running_min, max(queries_running) AS queries_running_max, avg(queries_queued) AS queries_queued,

min(queries_queued) AS queries_queued_min, max(queries_queued) AS queries_queued_max

FROM database_history

GROUP BY sample_time );

To change the interval for averaging results, adjust the value specified for date_trunc. Valid values are microseconds, milliseconds, second, minute, hour, day, week, month, quarter, year, decade, century and millennium.

Note: You use can also the Command Center Console to view historical query metrics. See the Command Center Console online help for more information.

Uninstalling Greenplum Command Center

To uninstall, you must stop both the Command Center Console and disable the Command Center data collection agents. Optionally, you may also want to remove any data associated with Greenplum Command Center by removing your Command Center Console installation and the Command Center database.

To uninstall the Command Center Console

1.Stop Command Center Console if it is currently running. For example:

$ gpcmdr --stop

2.Remove the Command Center installation directory. For example:

$ rm -rf /usr/local/greenplum-cc-web-version

To disable the Command Center Agents

• • Log in to the master host as the Greenplum administrative user (gpadmin): su - gpadmin

  • Edit $MASTER_DATA_DIRECTORY/postgresql.conf and disable the Command Center data collection agents: gp_enable_gpperfmon = off

3.Remove or comment out the gpmon entries in pg_hba.conf. For example:

#local gpperfmon gpmon md5

#host gpperfmon gpmon 0.0.0.0/0 md5

4.Drop the Command Center superuser role from the database. For example:

$ psql template1 -c 'DROP ROLE gpmon;'

5.Restart the Greenplum Database instance:

$ gpstop -r

6.Clean up any uncommitted Command Center data and log files that reside on the master file system:

$ rm $MASTER_DATA_DIRECTORY/gpperfmon/data/*

$ rm $MASTER_DATA_DIRECTORY/gpperfmon/logs/*

7.If you do not want to keep your historical Command Center data, drop the gpperfmon database:

$ dropdb gpperfmon