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Postgres SQL

Agent Check Agent Check

Supported OS: Linux Mac OS Windows

PostgreSQL Graph

Overview

Get metrics from the PostgreSQL service in real time to:

  • Visualize and monitor PostgreSQL states
  • Received notifications about PostgreSQL failovers and events

Setup

Follow the instructions below to install and configure this check for an Agent running on a host. For containerized environments, see the Autodiscovery Integration Templates for guidance on applying these instructions.

Installation

The PostgreSQL check is packaged with the Agent. To start gathering your PostgreSQL metrics and logs, install the Agent.

Configuration

Edit the postgres.d/conf.yaml file, in the conf.d/ folder at the root of your Agent’s configuration directory to start collecting your PostgreSQL metrics and logs. See the sample postgres.d/conf.yaml for all available configuration options.

Prepare Postgres

To get started with the PostgreSQL integration, create a read-only datadog user with proper access to your PostgreSQL server. Start psql on your PostgreSQL database and run:

For PostgreSQL version 10 and above:

create user datadog with password '<PASSWORD>';
grant pg_monitor to datadog;

For older PostgreSQL versions:

create user datadog with password '<PASSWORD>';
grant SELECT ON pg_stat_database to datadog;

Note: When generating custom metrics that require querying additional tables, you may need to grant the CONNECT permission on those tables to the datadog user.

To verify the permissions are correct, run the following command:

psql -h localhost -U datadog postgres -c \
"select * from pg_stat_database LIMIT(1);" \
&& echo -e "\e[0;32mPostgres connection - OK\e[0m" \
|| echo -e "\e[0;31mCannot connect to Postgres\e[0m"

When it prompts for a password, enter the one used in the first command.

Metric collection

  • Edit the postgres.d/conf.yaml file to point to your server / port and set the masters to monitor. See the sample postgres.d/conf.yaml for all available configuration options.
OptionRequiredDescription
usernameNoThe user account used to collect metrics, created in the Installation section above.
passwordNoThe password for the user account.
dbnameNoThe name of the database you want to monitor.
sslNoDefaults to False. Indicates whether to use an SSL connection.
tagsNoA list of tags applied to all metrics collected. Tags may be simple strings or key-value pairs.
relationsNoBy default, all schemas are included. Add specific schemas here to collect metrics for schema relations. Each relation generates 10 metrics and an additional 10 metrics per index.
collect_function_metricsNoCollect metrics regarding PL/pgSQL functions from pg_stat_user_functions.
collect_count_metricsNoCollect count metrics. The default value is True for backward compatibility, but this might be slow. The recommended value is False.
collect_activity_metricsNoDefaults to False. Collect metrics regarding transactions from pg_stat_activity. Make sure the user has sufficient privileges to read from pg_stat_activity before enabling this option.
collect_database_size_metricsYesCollect database size metrics. Default value is True but this might be slow with large databases.
collect_default_databaseNoDefaults to False. Include statistics from the default database postgres in the check metrics.

For PostgreSQL versions 9.6 and below, run the following and create a SECURITY DEFINER to read from pg_stat_activity.

CREATE FUNCTION pg_stat_activity() RETURNS SETOF pg_catalog.pg_stat_activity AS
$$ SELECT * from pg_catalog.pg_stat_activity; $$
LANGUAGE sql VOLATILE SECURITY DEFINER;

CREATE VIEW pg_stat_activity_dd AS SELECT * FROM pg_stat_activity();
grant SELECT ON pg_stat_activity_dd to datadog;

Log collection

Available for Agent >6.0

PostgreSQL default logging is to stderr and logs do not include detailed information. It is recommended to log into a file with additional details specified in the log line prefix.

  1. Edit your PostgreSQL configuration file /etc/postgresql/<version>/main/postgresql.conf and uncomment the following parameter in the log section:

      logging_collector = on
      log_directory = 'pg_log'  # directory where log files are written,
                                # can be absolute or relative to PGDATA
      log_filename = 'pg.log'   #log file name, can include pattern
      log_statement = 'all'     #log all queries
      log_line_prefix= '%m [%p] %d %a %u %h %c '
      log_file_mode = 0644
      ## For Windows
      #log_destination = 'eventlog'
  2. Collecting logs is disabled by default in the Datadog Agent, enable it in your datadog.yaml file:

      logs_enabled: true
  3. Add this configuration block to your postgres.d/conf.yaml file to start collecting your PostgreSQL logs:

      logs:
          - type: file
            path: /var/log/pg_log/pg.log
            source: postgresql
            sourcecategory: database
            service: myapp
            #To handle multi line that starts with yyyy-mm-dd use the following pattern
            #log_processing_rules:
            #  - type: multi_line
            #    pattern: \d{4}\-(0?[1-9]|1[012])\-(0?[1-9]|[12][0-9]|3[01])
            #    name: new_log_start_with_date

    Change the service and path parameter values to configure for your environment. See the sample postgres.d/conf.yaml for all available configuration options.

  4. Restart the Agent.

Validation

Run the Agent’s status subcommand and look for postgres under the Checks section.

Data Collected

Some of the metrics listed below require additional configuration, see the sample postgres.d/conf.yaml for all configurable options.

Metrics

postgresql.connections
(gauge)
The number of active connections to this database.
Shown as connection
postgresql.commits
(gauge)
The number of transactions that have been committed in this database.
Shown as transaction
postgresql.rollbacks
(gauge)
The number of transactions that have been rolled back in this database.
Shown as transaction
postgresql.disk_read
(gauge)
The number of disk blocks read in this database.
Shown as block
postgresql.buffer_hit
(gauge)
The number of times disk blocks were found in the buffer cache, preventing the need to read from the database.
Shown as hit
postgresql.rows_returned
(gauge)
The number of rows returned by queries in this database
Shown as row
postgresql.rows_fetched
(gauge)
The number of rows fetched by queries in this database
Shown as row
postgresql.rows_inserted
(gauge)
The number of rows inserted by queries in this database
Shown as row
postgresql.rows_updated
(gauge)
The number of rows updated by queries in this database
Shown as row
postgresql.rows_deleted
(gauge)
The number of rows deleted by queries in this database
Shown as row
postgresql.database_size
(gauge)
The disk space used by this database.
Shown as byte
postgresql.deadlocks
(gauge)
The number of deadlocks detected in this database
postgresql.temp_bytes
(gauge)
The amount of data written to temporary files by queries in this database.
Shown as byte
postgresql.temp_files
(gauge)
The number of temporary files created by queries in this database.
Shown as file
postgresql.bgwriter.checkpoints_timed
(count)
The number of scheduled checkpoints that were performed.
postgresql.bgwriter.checkpoints_requested
(count)
The number of requested checkpoints that were performed.
postgresql.bgwriter.buffers_checkpoint
(count)
The number of buffers written during checkpoints.
postgresql.bgwriter.buffers_clean
(count)
The number of buffers written by the background writer.
postgresql.bgwriter.maxwritten_clean
(count)
The number of times the background writer stopped a cleaning scan due to writing too many buffers.
postgresql.bgwriter.buffers_backend
(count)
The number of buffers written directly by a backend.
Shown as buffer
postgresql.bgwriter.buffers_alloc
(count)
The number of buffers allocated
postgresql.bgwriter.buffers_backend_fsync
(count)
The of times a backend had to execute its own fsync call instead of the background writer.
postgresql.bgwriter.write_time
(count)
The total amount of checkpoint processing time spent writing files to disk.
Shown as millisecond
postgresql.bgwriter.sync_time
(count)
The total amount of checkpoint processing time spent synchronizing files to disk.
Shown as millisecond
postgresql.locks
(gauge)
The number of locks active for this database.
Shown as lock
postgresql.seq_scans
(gauge)
The number of sequential scans initiated on this table.
postgresql.seq_rows_read
(gauge)
The number of live rows fetched by sequential scans.
Shown as row
postgresql.index_scans
(gauge)
The number of index scans initiated on this table.
postgresql.index_rows_fetched
(gauge)
The number of live rows fetched by index scans.
Shown as row
postgresql.index_rel_rows_fetched
(gauge)
The number of live rows fetched by index scans.
Shown as row
postgresql.rows_hot_updated
(gauge)
The number of rows HOT updated, meaning no separate index update was needed.
Shown as row
postgresql.live_rows
(gauge)
The estimated number of live rows.
Shown as row
postgresql.dead_rows
(gauge)
The estimated number of dead rows.
Shown as row
postgresql.index_rows_read
(gauge)
The number of index entries returned by scans on this index.
Shown as row
postgresql.table_size
(gauge)
The total disk space used by the specified table. Includes TOAST, free space map, and visibility map. Excludes indexes.
Shown as byte
postgresql.index_size
(gauge)
The total disk space used by indexes attached to the specified table.
Shown as byte
postgresql.total_size
(gauge)
The total disk space used by the table, including indexes and TOAST data.
Shown as byte
postgresql.table.count
(gauge)
The number of user tables in this database.
Shown as table
postgresql.max_connections
(gauge)
The maximum number of client connections allowed to this database.
Shown as connection
postgresql.percent_usage_connections
(gauge)
The number of connections to this database as a fraction of the maximum number of allowed connections.
Shown as fraction
postgresql.replication_delay
(gauge)
The current replication delay in seconds. Only available with postgresql 9.1 and newer
Shown as second
postgres.replication_delay_bytes
(gauge)
Deprecated please use postgresql.replication_delay_bytes instead
Shown as byte
postgresql.replication_delay_bytes
(gauge)
The current replication delay in bytes. Only available with postgresql 9.2 and newer
Shown as byte
postgresql.heap_blocks_read
(gauge)
The number of disk blocks read from this table.
Shown as block
postgresql.heap_blocks_hit
(gauge)
The number of buffer hits in this table.
Shown as hit
postgresql.index_blocks_read
(gauge)
The number of disk blocks read from all indexes on this table.
Shown as block
postgresql.index_blocks_hit
(gauge)
The number of buffer hits in all indexes on this table.
Shown as hit
postgresql.toast_blocks_read
(gauge)
The number of disk blocks read from this table's TOAST table.
Shown as block
postgresql.toast_blocks_hit
(gauge)
The number of buffer hits in this table's TOAST table.
Shown as hit
postgresql.toast_index_blocks_read
(gauge)
The number of disk blocks read from this table's TOAST table index.
Shown as block
postgresql.toast_index_blocks_hit
(gauge)
The number of buffer hits in this table's TOAST table index.
Shown as block
postgresql.transactions.open
(gauge)
The number of open transactions in this database.
Shown as transaction
postgresql.transactions.idle_in_transaction
(gauge)
The number of 'idle in transaction' transactions in this database.
Shown as transaction
postgresql.before_xid_wraparound
(gauge)
The number of transactions that can occur until a transaction wraparound.
Shown as transaction
postgresql.active_queries
(gauge)
The number of active queries in this database.
postgresql.waiting_queries
(gauge)
The number of waiting queries in this database.

Events

The PostgreSQL check does not include any events.

Service Checks

postgres.can_connect:
Returns CRITICAL if the Agent is unable to connect to the monitored PostgreSQL instance, otherwie returns OK.

Further Reading

Additional helpful documentation, links, and articles:

FAQ

Blog posts


Mistake in the docs? Feel free to contribute!