pgmon/sample-config/pgmon-metrics.yml

metrics:
  ##
  # Discovery metrics
  ##
  discover_dbs:
    type: set
    query:
      0: >
        SELECT datname AS dbname
        FROM pg_database
  discover_rep:
    type: set
    query:
      0: >
        SELECT client_addr || '_' || regexp_replace(application_name, '[ ,]', '_', 'g') AS repid,
               client_addr,
               state
        FROM pg_stat_replication
  discover_slots:
    type: set
    query:
      90400: >
        SELECT slot_name,
               plugin,
               slot_type,
               database,
               false as temporary,
               active
        FROM pg_replication_slots
      100000: >
        SELECT slot_name,
               plugin,
               slot_type,
               database,
               temporary,
               active
        FROM pg_replication_slots

  ##
  # cluster-wide metrics
  ##
  version:
    type: value
    query:
      0: SHOW server_version_num

  max_frozen_age:
    type: row
    query:
      0: >
        SELECT max(age(datfrozenxid)) AS xid_age,
               0 AS mxid_age
        FROM pg_database
      90600: >
        SELECT max(age(datfrozenxid)) AS xid_age,
               max(mxid_age(datminmxid)) AS mxid_age
        FROM pg_database

  bgwriter:
    type: row
    query:
      0: >
        SELECT checkpoints_timed,
               checkpoints_req,
               checkpoint_write_time,
               checkpoint_sync_time,
               buffers_checkpoint,
               buffers_clean,
               maxwritten_clean,
               buffers_backend,
               buffers_backend_fsync,
               buffers_alloc
        FROM pg_stat_bgwriter
      170000: >
        SELECT cp.num_timed AS checkpoints_timed,
               cp.num_requested AS checkpoints_req,
               cp.write_time AS checkpoint_write_time,
               cp.sync_time AS checkpoint_sync_time,
               cp.buffers_written AS buffers_checkpoint,
               bg.buffers_clean AS buffers_clean,
               bg.maxwritten_clean AS maxwritten_clean,
               NULL AS buffers_backend,
               NULL AS buffers_backend_fsync,
               bg.buffers_alloc AS buffers_alloc
        FROM pg_stat_bgwriter bg
        CROSS JOIN pg_stat_checkpointer cp


  ##
  # Per-database metrics
  ##
  db_stats:
    type: row
    query:
      0: >
        SELECT numbackends,
               xact_commit,
               xact_rollback,
               blks_read,
               blks_hit,
               tup_returned,
               tup_fetched,
               tup_inserted,
               tup_updated,
               tup_deleted,
               conflicts,
               temp_files,
               temp_bytes,
               deadlocks,
               0 AS checksum_failures,
               blk_read_time,
               blk_write_time,
               0 AS session_time,
               0 AS active_time,
               0 AS idle_in_transaction_time,
               0 AS sessions,
               0 AS sessions_abandoned,
               0 AS sessions_fatal,
               0 AS sessions_killed,
               extract('epoch' from stats_reset)::float AS stats_reset
        FROM pg_stat_database WHERE datname = %(dbname)s
      140000: >
        SELECT numbackends,
               xact_commit,
               xact_rollback,
               blks_read,
               blks_hit,
               tup_returned,
               tup_fetched,
               tup_inserted,
               tup_updated,
               tup_deleted,
               conflicts,
               temp_files,
               temp_bytes,
               deadlocks,
               COALESCE(checksum_failures,
               0) AS checksum_failures,
               blk_read_time,
               blk_write_time,
               session_time,
               active_time,
               idle_in_transaction_time,
               sessions,
               sessions_abandoned,
               sessions_fatal,
               sessions_killed,
               extract('epoch' from stats_reset)::float AS stats_reset
        FROM pg_stat_database WHERE datname = %(dbname)s
    test_args:
      dbname: postgres

  hit_ratios:
    type: row
    query:
      0: >
        SELECT sum(heap_blks_read)::float / NULLIF(sum(heap_blks_read + heap_blks_hit), 0) AS avg_heap_hit_ratio,
               sum(idx_blks_hit)::float / NULLIF(sum(idx_blks_read + idx_blks_hit), 0) AS avg_idx_hit_ratio,
               sum(toast_blks_hit)::float / NULLIF(sum(toast_blks_read + toast_blks_hit), 0) AS avg_toast_hit_ratio,
               sum(tidx_blks_hit)::float / NULLIF(sum(tidx_blks_read + tidx_blks_hit), 0) AS avg_tidx_hit_ratio
        FROM pg_statio_all_tables
    test_args:
      dbname: postgres

  activity:
    type: set
    query:
      0: >
        SELECT state,
               count(*) AS backend_count,
               COALESCE(EXTRACT(EPOCH FROM max(now() - state_change))::float, 0) AS max_state_time
        FROM pg_stat_activity
        WHERE datname = %(dbname)s
        GROUP BY state
    test_args:
      dbname: postgres


  ##
  # Per-replication metrics
  ##
  rep_stats:
    type: row
    query:
      90400: >
        SELECT pid, usename,
               EXTRACT(EPOCH FROM backend_start)::integer AS backend_start,
               state,
               pg_xlog_location_diff(pg_current_xlog_location(), sent_location) AS sent_lsn,
               pg_xlog_location_diff(pg_current_xlog_location(), write_location) AS write_lsn,
               pg_xlog_location_diff(pg_current_xlog_location(), flush_location) AS flush_lsn,
               pg_xlog_location_diff(pg_current_xlog_location(), replay_location) AS replay_lsn,
               NULL AS write_lag,
               NULL AS flush_lag,
               NULL AS replay_lag,
               sync_state
        FROM pg_stat_replication
        WHERE client_addr || '_' || regexp_replace(application_name, '[ ,]', '_', 'g') = %(repid)s
      100000: >
        SELECT pid, usename,
               EXTRACT(EPOCH FROM backend_start)::integer AS backend_start,
               state,
               pg_wal_lsn_diff(pg_current_wal_lsn(), sent_lsn) AS sent_lsn,
               pg_wal_lsn_diff(pg_current_wal_lsn(), write_lsn) AS write_lsn,
               pg_wal_lsn_diff(pg_current_wal_lsn(), flush_lsn) AS flush_lsn,
               pg_wal_lsn_diff(pg_current_wal_lsn(), replay_lsn) AS replay_lsn,
               COALESCE(EXTRACT(EPOCH FROM write_lag), 0)::integer AS write_lag,
               COALESCE(EXTRACT(EPOCH FROM flush_lag), 0)::integer AS flush_lag,
               COALESCE(EXTRACT(EPOCH FROM replay_lag), 0)::integer AS replay_lag,
               sync_state
        FROM pg_stat_replication WHERE client_addr || '_' || regexp_replace(application_name, '[ ,]', '_', 'g') = %(repid)s
    test_args:
      repid: 127.0.0.1_test_rep


  ##
  # Per-slot metrics
  ##
  slot_stats:
    type: row
    query:
      90400: >
        SELECT NULL as active_pid,
               xmin,
               pg_xlog_location_diff(pg_current_xlog_location(), restart_lsn) AS restart_bytes,
               NULL AS confirmed_flush_bytes
        FROM pg_replication_slots WHERE slot_name = %(slot)s
      90600: >
        SELECT active_pid,
               xmin,
               pg_xlog_location_diff(pg_current_xlog_location(), restart_lsn) AS restart_bytes,
               pg_xlog_location_diff(pg_current_xlog_location(), confirmed_flush_lsn) AS confirmed_flush_bytes
        FROM pg_replication_slots WHERE slot_name = %(slot)s
      100000: >
        SELECT active_pid,
               xmin,
               pg_wal_lsn_diff(pg_current_wal_lsn(), restart_lsn) AS restart_bytes,
               pg_wal_lsn_diff(pg_current_wal_lsn(), confirmed_flush_lsn) AS confirmed_flush_bytes
        FROM pg_replication_slots WHERE slot_name = %(slot)s
    test_args:
      slot: test_slot

  ##
  # Debugging
  ##
  ntables:
    type: value
    query:
      0: SELECT count(*) AS ntables FROM pg_stat_user_tables