PostgreSQL

Plugin: go.d.plugin Module: postgres

Overview

This collector monitors the activity and performance of Postgres servers, collects replication statistics, metrics for each database, table and index, and more.

It establishes a connection to the Postgres instance via a TCP or UNIX socket. To collect metrics for database tables and indexes, it establishes an additional connection for each discovered database.

This collector is supported on all platforms.

This collector supports collecting metrics from multiple instances of this integration, including remote instances.

Default Behavior

Auto-Detection

By default, it detects instances running on localhost by trying to connect as root and netdata using known PostgreSQL TCP and UNIX sockets:

• 127.0.0.1:5432
• /var/run/postgresql/

Limits

Table and index metrics are not collected for databases with more than 50 tables or 250 indexes. These limits can be changed in the configuration file.

Performance Impact

The default configuration for this integration is not expected to impose a significant performance impact on the system.

Setup

Prerequisites

Create netdata user

Create a user with granted pg_monitor or pg_read_all_stat built-in role.

To create the netdata user with these permissions, execute the following in the psql session, as a user with CREATEROLE privileges:

CREATE USER netdata;
GRANT pg_monitor TO netdata;

After creating the new user, restart the Netdata Agent with sudo systemctl restart netdata, or the appropriate method for your system.

Configuration

File

The configuration file name for this integration is go.d/postgres.conf.

You can edit the configuration file using the edit-config script from the Netdata config directory.

cd /etc/netdata 2>/dev/null || cd /opt/netdata/etc/netdata
sudo ./edit-config go.d/postgres.conf

Options

The following options can be defined globally: update_every, autodetection_retry.

Examples

TCP socket

An example configuration.

jobs:
  - name: local
    dsn: 'postgresql://netdata@127.0.0.1:5432/postgres'

Unix socket

An example configuration.

jobs:
  - name: local
    dsn: 'host=/var/run/postgresql dbname=postgres user=netdata'

Multi-instance

Note: When you define multiple jobs, their names must be unique.

Local and remote instances.

jobs:
  - name: local
    dsn: 'postgresql://netdata@127.0.0.1:5432/postgres'

  - name: remote
    dsn: 'postgresql://netdata@203.0.113.0:5432/postgres'

Metrics

Metrics grouped by scope.

The scope defines the instance that the metric belongs to. An instance is uniquely identified by a set of labels.

Per PostgreSQL instance

These metrics refer to the entire monitored application.

This scope has no labels.

Metrics:

Per repl application

These metrics refer to the replication application.

Labels:

Metrics:

Per repl slot

These metrics refer to the replication slot.

Labels:

Metrics:

Per database

These metrics refer to the database.

Labels:

Metrics:

Per table

These metrics refer to the database table.

Labels:

Metrics:

Per index

These metrics refer to the table index.

Labels:

Metrics:

Alerts

The following alerts are available:

Troubleshooting

Debug Mode

Important: Debug mode is not supported for data collection jobs created via the UI using the Dyncfg feature.

To troubleshoot issues with the postgres collector, run the go.d.plugin with the debug option enabled. The output should give you clues as to why the collector isn’t working.

• Navigate to the plugins.d directory, usually at /usr/libexec/netdata/plugins.d/. If that’s not the case on your system, open netdata.conf and look for the plugins setting under [directories].

  cd /usr/libexec/netdata/plugins.d/
  

• Switch to the netdata user.

  sudo -u netdata -s
  

• Run the go.d.plugin to debug the collector:

  ./go.d.plugin -d -m postgres
  

Getting Logs

If you’re encountering problems with the postgres collector, follow these steps to retrieve logs and identify potential issues:

• Run the command specific to your system (systemd, non-systemd, or Docker container).
• Examine the output for any warnings or error messages that might indicate issues. These messages should provide clues about the root cause of the problem.

System with systemd

Use the following command to view logs generated since the last Netdata service restart:

journalctl _SYSTEMD_INVOCATION_ID="$(systemctl show --value --property=InvocationID netdata)" --namespace=netdata --grep postgres

System without systemd

Locate the collector log file, typically at /var/log/netdata/collector.log, and use grep to filter for collector’s name:

grep postgres /var/log/netdata/collector.log

Note: This method shows logs from all restarts. Focus on the latest entries for troubleshooting current issues.

Docker Container

If your Netdata runs in a Docker container named “netdata” (replace if different), use this command:

docker logs netdata 2>&1 | grep postgres