Alerts

On the Admin> Alerts page, an administrator can set up alert rules to detect and respond to events occurring in the Greenplum Database system and in currently executing database queries. When a rule is matched, Command Center logs a record.

You can set up email alerts by configuring an SMTP server in Greenplum Database or in Command Center. Additionally, you can create a send-alert.sh shell script to forward alerts to other destinations, such as an SMS gateway or a Slack channel. If the script is present, Command Center runs it whenever an alert is raised.

Command Center creates the gpmetrics schema in the gpperfmon database to store both rules and log records. See gpmetrics Schema Reference for information about the gpcc_alert_rule and gpcc_alert_log tables in the gpmetrics schema.

This topic contains the following subtopics:

• Configuring Alert Rules

• Configuring Alert Email

• Creating a Send Alert Script

Configuring Alert Rules

Click EDIT to manage alert event rules. To enable an alert rule, enter any data required in the fields and check the box. Uncheck the box to disable the rule. Click SAVE when you have finished making changes to the alert configuration.

     100 - sum(<available disk space>) / sum(<total disk space>) * 100

Configuring Alert Email

Command Center requires an SMTP server to send alert emails. If SMTP has been configured for Greenplum Database, Command Center will use the configured SMTP server, and if provided, the SMTP user and password. You must enter values for the fields in the right column, Send emails to, and From, whether you use the Greenplum Database SMTP server or configure another one.

Command Center first attempts an encrypted TLS connection and then falls back to an unencrypted connection if TLS is not supported. The SMTP server must support one of the following authentication methods: NONE, PLAIN, LOGIN, or CRAM-MD5. Command Center will use the most secure of these methods the SMTP server allows.

Configuring email With Command Center

Click EDIT in the Manage email configuration panel.

The alert email configuration is set with the following Greenplum Database server configuration parameters:

When you click SAVE, Command Center sends a test email to the addresses in the Send emails to field. The email contains a list of the currently configured alert rules. If there is an error in the SMTP server or username/password configuration and the email cannot be sent, Command Center displays an error message.

Configuring email for Greenplum Database

The following server configuration parameters are used to configure SMTP email for Greenplum Database.

Command Center uses the gp_email_smtp_server, gp_email_smtp_userid, and gp_email_smtp_password parameters if they are set. It ignores the remaining parameters.

You can check the current value of a configuration parameter by running the gpconfig -s command on the master host, for example:

$ gpconfig -s gp_email_smtp_server

Use the gpconfig -c option to set the values of server configuration parameters, for example:

$ gpconfig -c gp_email_smtp_server -v "smtp.example.com:465" 
$ gpconfig -c gp_email_smtp_userid -v "gpcc-alerts@example.com"
$ gpconfig -c gp_email_smtp_password -v "changeme"
$ gpconfig -c gp_email_from -v "gpcc-alerts@example.com"
$ gpconfig -c gp_email_to -v "gpcc-admin@example.com;gpdb-admin@example.com"

Run gpstop -u to reload the configuration files after changing these configuration parameters.

Creating a Send Alert Script

The send alert script is a shell script that you can use to send Command Center alerts to destinations such as SMS gateways, pagers, team collaboration tools like Slack, chat servers, archive files, alternative email servers, and so on. You can use the send alert script in addition to sending email from Command Center, or as an alternative to sending alert emails from Command Center.

Command Center looks for the script $MASTER_DATA_DIRECTORY/gpmetrics/send-alert.sh on the host where Command Center is running—either the master host or standby host. If the file exists and is executable by the gpadmin user, Command Center executes the script. The following variables are set on the command line when the script runs.

An example script that you can customize is provided at $GPCC_HOME/alert-email/send_alert.sh.sample. The example formats the alert as HTML email text and pipes it through the Linux mail command.

To set up a send alert script:

1. Copy the $GPCC_HOME/alert-email/send_alert.sh.sample file to $MASTER_DATA_DIRECTORY/gpmetrics/send-alert.sh.

2. Customize the script with code to format and deliver the alert to your desired destination.

3. Run gpcc start to restart Command Center and enable the script.