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.

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:

Metric	Dimensions	Unit
postgres.connections_utilization	used	percentage
postgres.connections_usage	available, used	connections
postgres.connections_state_count	active, idle, idle_in_transaction, idle_in_transaction_aborted, disabled	connections
postgres.transactions_duration	a dimension per bucket	transactions/s
postgres.queries_duration	a dimension per bucket	queries/s
postgres.locks_utilization	used	percentage
postgres.checkpoints_rate	scheduled, requested	checkpoints/s
postgres.checkpoints_time	write, sync	milliseconds
postgres.bgwriter_halts_rate	maxwritten	events/s
postgres.buffers_io_rate	checkpoint, backend, bgwriter	B/s
postgres.buffers_backend_fsync_rate	fsync	calls/s
postgres.buffers_allocated_rate	allocated	B/s
postgres.wal_io_rate	write	B/s
postgres.wal_files_count	written, recycled	files
postgres.wal_archiving_files_count	ready, done	files/s
postgres.autovacuum_workers_count	analyze, vacuum_analyze, vacuum, vacuum_freeze, brin_summarize	workers
postgres.txid_exhaustion_towards_autovacuum_perc	emergency_autovacuum	percentage
postgres.txid_exhaustion_perc	txid_exhaustion	percentage
postgres.txid_exhaustion_oldest_txid_num	xid	xid
postgres.catalog_relations_count	ordinary_table, index, sequence, toast_table, view, materialized_view, composite_type, foreign_table, partitioned_table, partitioned_index	relations
postgres.catalog_relations_size	ordinary_table, index, sequence, toast_table, view, materialized_view, composite_type, foreign_table, partitioned_table, partitioned_index	B
postgres.uptime	uptime	seconds
postgres.databases_count	databases	databases

Per repl application

These metrics refer to the replication application.

Labels:

Label	Description
application	application name

Metrics:

Metric	Dimensions	Unit
postgres.replication_app_wal_lag_size	sent_lag, write_lag, flush_lag, replay_lag	B
postgres.replication_app_wal_lag_time	write_lag, flush_lag, replay_lag	seconds

Per repl slot

These metrics refer to the replication slot.

Labels:

Label	Description
slot	replication slot name

Metrics:

Metric	Dimensions	Unit
postgres.replication_slot_files_count	wal_keep, pg_replslot_files	files

Per database

These metrics refer to the database.

Labels:

Label	Description
database	database name

Metrics:

Metric	Dimensions	Unit
postgres.db_transactions_ratio	committed, rollback	percentage
postgres.db_transactions_rate	committed, rollback	transactions/s
postgres.db_connections_utilization	used	percentage
postgres.db_connections_count	connections	connections
postgres.db_cache_io_ratio	miss	percentage
postgres.db_io_rate	memory, disk	B/s
postgres.db_ops_fetched_rows_ratio	fetched	percentage
postgres.db_ops_read_rows_rate	returned, fetched	rows/s
postgres.db_ops_write_rows_rate	inserted, deleted, updated	rows/s
postgres.db_conflicts_rate	conflicts	queries/s
postgres.db_conflicts_reason_rate	tablespace, lock, snapshot, bufferpin, deadlock	queries/s
postgres.db_deadlocks_rate	deadlocks	deadlocks/s
postgres.db_locks_held_count	access_share, row_share, row_exclusive, share_update, share, share_row_exclusive, exclusive, access_exclusive	locks
postgres.db_locks_awaited_count	access_share, row_share, row_exclusive, share_update, share, share_row_exclusive, exclusive, access_exclusive	locks
postgres.db_temp_files_created_rate	created	files/s
postgres.db_temp_files_io_rate	written	B/s
postgres.db_size	size	B

Per table

These metrics refer to the database table.

Labels:

Label	Description
database	database name
schema	schema name
table	table name
parent_table	parent table name

Metrics:

Metric	Dimensions	Unit
postgres.table_rows_dead_ratio	dead	percentage
postgres.table_rows_count	live, dead	rows
postgres.table_ops_rows_rate	inserted, deleted, updated	rows/s
postgres.table_ops_rows_hot_ratio	hot	percentage
postgres.table_ops_rows_hot_rate	hot	rows/s
postgres.table_cache_io_ratio	miss	percentage
postgres.table_io_rate	memory, disk	B/s
postgres.table_index_cache_io_ratio	miss	percentage
postgres.table_index_io_rate	memory, disk	B/s
postgres.table_toast_cache_io_ratio	miss	percentage
postgres.table_toast_io_rate	memory, disk	B/s
postgres.table_toast_index_cache_io_ratio	miss	percentage
postgres.table_toast_index_io_rate	memory, disk	B/s
postgres.table_scans_rate	index, sequential	scans/s
postgres.table_scans_rows_rate	index, sequential	rows/s
postgres.table_autovacuum_since_time	time	seconds
postgres.table_vacuum_since_time	time	seconds
postgres.table_autoanalyze_since_time	time	seconds
postgres.table_analyze_since_time	time	seconds
postgres.table_null_columns	null	columns
postgres.table_size	size	B
postgres.table_bloat_size_perc	bloat	percentage
postgres.table_bloat_size	bloat	B

Per index

These metrics refer to the table index.

Labels:

Label	Description
database	database name
schema	schema name
table	table name
parent_table	parent table name
index	index name

Metrics:

Metric	Dimensions	Unit
postgres.index_size	size	B
postgres.index_bloat_size_perc	bloat	percentage
postgres.index_bloat_size	bloat	B
postgres.index_usage_status	used, unused	status

Functions

This collector exposes real-time functions for interactive troubleshooting in the Top tab.

Top Queries

Retrieves aggregated SQL query performance metrics from PostgreSQL pg_stat_statements extension.

This function queries pg_stat_statements which tracks execution statistics for all SQL statements. Statistics include execution counts, timing metrics, I/O operations, and resource consumption. Columns are dynamically detected based on your PostgreSQL version.

Use cases:

• Identify slow queries consuming the most total execution time
• Find queries with high shared block reads for I/O optimization
• Analyze temp block usage to detect queries needing memory tuning

Query text is truncated at 4096 characters for display purposes.

Aspect	Description
Name	Postgres:top-queries
Require Cloud	yes
Performance	Queries pg_stat_statements which maintains statistics in shared memory: • On busy servers with many unique queries, the extension may consume significant memory • Default limit of 500 rows balances usefulness with performance
Security	Query text may contain unmasked literal values including potentially sensitive data: • Personal information in WHERE clauses or INSERT values • Business data and internal identifiers • Access should be restricted to authorized personnel only
Availability	Available when: • The pg_stat_statements extension is installed in the database • The collector has successfully connected to PostgreSQL • Returns HTTP 503 if extension is not installed (with instructions to install) • Returns HTTP 500 if the query fails • Returns HTTP 504 if the query times out

Prerequisites

Enable pg_stat_statements

The pg_stat_statements extension must be installed and configured.

1. Add to postgresql.conf:

   shared_preload_libraries = 'pg_stat_statements'

2. Restart PostgreSQL, then create the extension:

   CREATE EXTENSION pg_stat_statements;

3. Verify the extension is working:

   SELECT COUNT(*) FROM pg_stat_statements;

info

• pg_stat_statements requires a server restart to load the shared library
• Statistics can be reset with SELECT pg_stat_statements_reset()
• The pg_stat_statements.max parameter controls maximum tracked statements (default 5000)
• Enable track_io_timing for block read/write timing metrics (may add slight overhead)

Parameters

Parameter	Type	Description	Required	Default	Options
Filter By	select	Select the primary sort column. Options include total time, mean time, calls, rows, shared blocks hit/read, and temp blocks written. Defaults to total time to focus on most resource-intensive queries.	yes	totalTime

Returns

Aggregated query statistics from pg_stat_statements. Each row represents a unique query pattern with cumulative metrics across all executions.

Column	Type	Unit	Visibility	Description
Query ID	string		hidden	Internal hash identifier for the normalized query. Can be used to track queries across statistics resets.
Query	string			Normalized SQL query text with literals replaced by parameter placeholders. Truncated to 4096 characters.
Database	string			Database name where the query was executed.
User	string			PostgreSQL user who executed the query.
Calls	integer			Total number of times this query pattern has been executed. High values indicate frequently run queries.
Total Time	duration	milliseconds		Cumulative execution time across all executions. High values indicate queries consuming significant database resources.
Mean Time	duration	milliseconds		Average execution time per call. Use this to compare typical performance across different query patterns.
Min Time	duration	milliseconds	hidden	Minimum execution time observed for a single execution.
Max Time	duration	milliseconds	hidden	Maximum execution time observed for a single execution. Large gaps between min and max may indicate performance variability.
Stddev Time	duration	milliseconds	hidden	Standard deviation of execution time. High values indicate inconsistent query performance.
Plans	integer		hidden	Number of times the query was planned. Available in PostgreSQL 13+.
Total Plan Time	duration	milliseconds	hidden	Cumulative time spent planning the query. Available in PostgreSQL 13+.
Mean Plan Time	duration	milliseconds	hidden	Average time spent planning per execution. Available in PostgreSQL 13+.
Min Plan Time	duration	milliseconds	hidden	Minimum planning time observed. Available in PostgreSQL 13+.
Max Plan Time	duration	milliseconds	hidden	Maximum planning time observed. Available in PostgreSQL 13+.
Stddev Plan Time	duration	milliseconds	hidden	Standard deviation of planning time. Available in PostgreSQL 13+.
Rows	integer			Total number of rows retrieved or affected across all executions.
Shared Blocks Hit	integer			Total shared buffer cache hits. High values indicate good cache utilization.
Shared Blocks Read	integer			Total shared blocks read from disk. High values indicate queries that bypass the cache and may benefit from more shared_buffers.
Shared Blocks Dirtied	integer		hidden	Total shared blocks dirtied by the query.
Shared Blocks Written	integer		hidden	Total shared blocks written by the query.
Local Blocks Hit	integer		hidden	Total local buffer cache hits (temporary tables).
Local Blocks Read	integer		hidden	Total local blocks read from disk.
Local Blocks Dirtied	integer		hidden	Total local blocks dirtied.
Local Blocks Written	integer		hidden	Total local blocks written.
Temp Blocks Read	integer			Total temp blocks read. Non-zero values indicate queries spilling to disk due to insufficient work_mem.
Temp Blocks Written	integer			Total temp blocks written. High values suggest increasing work_mem may improve performance.
Block Read Time	duration	milliseconds		Time spent reading blocks from disk. Requires track_io_timing to be enabled.
Block Write Time	duration	milliseconds		Time spent writing blocks to disk. Requires track_io_timing to be enabled.
WAL Records	integer		hidden	Total number of WAL records generated. Available in PostgreSQL 13+.
WAL Full Page Images	integer		hidden	Total number of WAL full page images generated. Available in PostgreSQL 13+.
WAL Bytes	integer		hidden	Total bytes of WAL generated. Available in PostgreSQL 13+.
JIT Functions	integer		hidden	Total number of functions JIT-compiled. Available in PostgreSQL 15+.
JIT Generation Time	duration	milliseconds	hidden	Time spent generating JIT code. Available in PostgreSQL 15+.
JIT Inlining Count	integer		hidden	Number of times JIT inlining was performed. Available in PostgreSQL 15+.
JIT Inlining Time	duration	milliseconds	hidden	Time spent on JIT inlining. Available in PostgreSQL 15+.
JIT Optimization Count	integer		hidden	Number of times JIT optimization was performed. Available in PostgreSQL 15+.
JIT Optimization Time	duration	milliseconds	hidden	Time spent on JIT optimization. Available in PostgreSQL 15+.
JIT Emission Count	integer		hidden	Number of times JIT code was emitted. Available in PostgreSQL 15+.
JIT Emission Time	duration	milliseconds	hidden	Time spent emitting JIT code. Available in PostgreSQL 15+.
Temp Block Read Time	duration	milliseconds	hidden	Time spent reading temp blocks. Available in PostgreSQL 15+. Requires track_io_timing.
Temp Block Write Time	duration	milliseconds	hidden	Time spent writing temp blocks. Available in PostgreSQL 15+. Requires track_io_timing.

Alerts

The following alerts are available:

Alert name	On metric	Description
postgres_total_connection_utilization	postgres.connections_utilization	average total connection utilization over the last minute
postgres_acquired_locks_utilization	postgres.locks_utilization	average acquired locks utilization over the last minute
postgres_txid_exhaustion_perc	postgres.txid_exhaustion_perc	percent towards TXID wraparound
postgres_db_cache_io_ratio	postgres.db_cache_io_ratio	average cache hit ratio in db ${label:database} over the last minute
postgres_db_transactions_rollback_ratio	postgres.db_cache_io_ratio	average aborted transactions percentage in db ${label:database} over the last five minutes
postgres_db_deadlocks_rate	postgres.db_deadlocks_rate	number of deadlocks detected in db ${label:database} in the last minute
postgres_table_cache_io_ratio	postgres.table_cache_io_ratio	average cache hit ratio in db ${label:database} table ${label:table} over the last minute
postgres_table_index_cache_io_ratio	postgres.table_index_cache_io_ratio	average index cache hit ratio in db ${label:database} table ${label:table} over the last minute
postgres_table_toast_cache_io_ratio	postgres.table_toast_cache_io_ratio	average TOAST hit ratio in db ${label:database} table ${label:table} over the last minute
postgres_table_toast_index_cache_io_ratio	postgres.table_toast_index_cache_io_ratio	average index TOAST hit ratio in db ${label:database} table ${label:table} over the last minute
postgres_table_bloat_size_perc	postgres.table_bloat_size_perc	bloat size percentage in db ${label:database} table ${label:table}
postgres_table_last_autovacuum_time	postgres.table_autovacuum_since_time	time elapsed since db ${label:database} table ${label:table} was vacuumed by the autovacuum daemon
postgres_table_last_autoanalyze_time	postgres.table_autoanalyze_since_time	time elapsed since db ${label:database} table ${label:table} was analyzed by the autovacuum daemon
postgres_index_bloat_size_perc	postgres.index_bloat_size_perc	bloat size percentage in db ${label:database} table ${label:table} index ${label:index}

Setup

You can configure the postgres collector in two ways:

Method	Best for	How to
UI	Fast setup without editing files	Go to Nodes → Configure this node → Collectors → Jobs, search for postgres, then click + to add a job.
File	If you prefer configuring via file, or need to automate deployments (e.g., with Ansible)	Edit go.d/postgres.conf and add a job.

important

UI configuration requires paid Netdata Cloud plan.

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

Options

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

Config options

Group	Option	Description	Default	Required
Collection	update_every	Data collection interval (seconds).	1	no
	autodetection_retry	Autodetection retry interval (seconds). Set 0 to disable.	0	no
Target	dsn	Postgres connection string (DSN). See DSN syntax.	postgres://postgres:postgres@127.0.0.1:5432/postgres	yes
	timeout	Query timeout (seconds).	2	no
Filters	collect_databases_matching	Database selector. Controls which databases are included. Uses simple patterns.		no
Limits	max_db_tables	Maximum number of tables per database to collect metrics for (0 = no limit).	50	no
	max_db_indexes	Maximum number of indexes per database to collect metrics for (0 = no limit).	250	no
Virtual Node	vnode	Associates this data collection job with a Virtual Node.		no

via UI

Configure the postgres collector from the Netdata web interface:

1. Go to Nodes.
2. Select the node where you want the postgres data-collection job to run and click the ⚙ (Configure this node). That node will run the data collection.
3. The Collectors → Jobs view opens by default.
4. In the Search box, type postgres (or scroll the list) to locate the postgres collector.
5. Click the + next to the postgres collector to add a new job.
6. Fill in the job fields, then click Test to verify the configuration and Submit to save.
   • Test runs the job with the provided settings and shows whether data can be collected.
   • If it fails, an error message appears with details (for example, connection refused, timeout, or command execution errors), so you can adjust and retest.

via File

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

The file format is YAML. Generally, the structure is:

update_every: 1
autodetection_retry: 0
jobs:
  - name: some_name1
  - name: some_name2

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

Examples

TCP socket

An example configuration.

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

Unix socket

An example configuration.

Config

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

Unix socket (custom port)

Connect to PostgreSQL using a Unix socket with a non-default port (5433).

Config

jobs:
  - name: local
    dsn: 'host=/var/run/postgresql port=5433 dbname=postgres user=netdata'

Multi-instance

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

Local and remote instances.

Config

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

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

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

  To debug a specific job:

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

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