postgres prometheus - ghdrako/doc_snipets GitHub Wiki

Exporting PostgreSQL metrics

1. Install the pg_prometheus extension on the PostgreSQL instance.

CREATE EXTENSION pg_prometheus;

2. Enable the pg_prometheus extension in the PostgreSQL instance. configure the pg_prometheus extension to expose the PostgreSQL metrics:

pg_prometheus.listen_addresses = 'localhost'
pg_prometheus.port = 9187

3. collecting PostgreSQL metrics

YAML
scrape_configs:
- job_name: 'postgresql'
scrape_interval: 10s
static_configs:
- targets: ['localhost:9187']

4. setting up Prometheus alerts

groups:
  - name: 'PostgreSQL alerts'
    rules:
      - alert: High CPU usage
        expr: postgresql_cpu_usage > sum(rate(postgresql_cpu_usage[5m])) by (instance) > 0.8
        for: 5m
        labels:
          severity: warning
        annotations:
          summary: High CPU usage on PostgreSQL {{ $labels.instance }}
          description: '{{ $labels.instance }} has high CPU

In this example, we are defining an alert rule named High CPU usage that triggers a warning when the sum of the rate of CPU usage for PostgreSQL instances is greater than 80% over a 5-minute window. The alert has a severity label of warning and includes annotations for the alert summary and description. To reload the Prometheus configuration, run the following command:

curl -X POST http://localhost:9090/-/reload

sending alerts to a notification channel We will use Alertmanager to send alerts to a notification channel, such as email or Slack. Follow these steps to set up Alertmanager:

1. Install Alertmanager on GCP.
2. Configure Alertmanager to send alerts to a notification channel. Here’s an example of how to configure Alertmanager to send alerts to an email address:

YAML
route:
group_by: ['alertname', 'severity']
group_wait: 30s
group_interval: 5m
repeat_interval: 12h
routes:
- match:
severity: warning
receiver: email-alerts
receivers:
- name: email-alerts
email_configs:
- to: '[email protected]'
from: '[email protected]'
smarthost: smtp.gmail.com:587
auth_username: '[email protected]'
auth_password: 'yourpassword'
starttls_require: true

In this example, we are configuring Alertmanager to send alerts with a severity label of warning to an email address. We are specifying the email address to send the alerts to, as well as the email address and credentials to use for authentication.