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;


  ##
  # 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

  activity:
    type: row
    query:
      0: >
        SELECT count(*) as backend_count,
               count(*) FILTER (WHERE state = 'idle') AS idle_count,
               count(*) FILTER (WHERE state = 'idle in transaction') AS idle_tx_count,
               COALESCE(EXTRACT(EPOCH FROM max(now() - state_change) FILTER (WHERE state = 'active'))::float, 0) AS max_active_time,
               COALESCE(EXTRACT(EPOCH FROM max(now() - state_change) FILTER (WHERE state = 'idle in transaction'))::float, 0) AS max_idle_tx_time
        FROM pg_stat_activity
        WHERE datname = %(dbname)s

  ##
  # Per-replication metrics
  ##
  rep_stats:
    type: row
    query:
      90400: SELECT pid, usename, EXTRACT(EPOCH FROM backend_start)::integer AS backend_start, state, sent_lsn, write_lsn, flush_lsn, 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 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