Один з методів отримання профілю робочого навантаження та історії очікувань у PostgreSQL

Продовження статті «Спроба створити аналог ASH для PostgreSQL ".

У статті буде розглянуто та показано на конкретних запитах та прикладах – яку ж корисну інформацію можна отримати за допомогою історії уявлення pg_stat_activity.

Попередження.
У зв'язку з новизною теми та незавершенням періоду тестування, стаття може містити помилки. Критика та зауваження всіляко вітаються та очікуються.

Вхідні дані

Історія подання pg_stat_statements

pg_stat_history

CREATE TABLE pg_stat_history ( 
id SERIAL, 
snapshot_timestamp  timestamp without time zone, 
database_id integer,
dbid oid,
userid oid,
queryid bigint,
query text,
calls bigint, 
total_time double precision, 
min_time double precision, 
max_time double precision, 
mean_time double precision,
stddev_time double precision,
rows bigint,
shared_blks_hit bigint, 
shared_blks_read bigint, 
shared_blks_dirtied bigint, 
shared_blks_written bigint, 
local_blks_hit bigint, 
local_blks_read bigint,
local_blks_dirtied bigint, 
local_blks_written bigint, 
temp_blks_read bigint,
temp_blks_written bigint,
blk_read_time double precision, 
blk_write_time double precision, 
baseline_id integer );

Таблиця заповнюється щогодини, використовуючи dblink до цільової бази даних. Найцікавіший і найкорисніший стовпець у таблиці, зрозуміло queryid.

Історія уявлення pg_stat_activity

archive_pg_stat_activity

CREATE TABLE archive_pg_stat_activity
(
  timepoint timestamp without time zone,
  datid             oid, 
  datname           name,
  pid               integer,
  usesysid          oid,
  usename           name,
  application_name  text,
  client_addr       inet,
  client_hostname   text,
  client_port       integer,
  backend_start     timestamp without time zone,
  xact_start        timestamp without time zone,
  query_start       timestamp without time zone,
  state_change      timestamp without time zone,
  wait_event_type   text,                     
  wait_event        text,                   
  state             text,                  
  backend_xid       xid,                 
  backend_xmin      xid,                
  query             text,               
  backend_type      text,
  queryid           bigint
);

Таблиця є секційованою по годинах таблицею history_pg_stat_activity (Докладніше тут — pg_stat_statements + pg_stat_activity + loq_query = pg_ash? і тут - Спроба створити аналог ASH для PostgreSQL.)

Вихідні дані

CLUSTER CPU TIME (SYSTEM + CLIENTS)

Запит

WITH 
 t AS
 (
	SELECT 		
			date_trunc('second', timepoint)
	FROM 	activity_hist.archive_pg_stat_activity aa
	WHERE 	timepoint BETWEEN pg_stat_history_begin+(current_hour_diff * interval '1 hour') AND pg_stat_history_end+(current_hour_diff * interval '1 hour')  AND 
			( aa.wait_event_type IS NULL  ) AND
			aa.state = 'active'
 )
 SELECT count(*) 
 INTO cpu_total
 FROM t ;

Приклад

CLUSTER CPU TIME (SYSTEM + CLIENTS ) : 28:37:46

CLUSTER WAITINGS TIME

Запит

WITH 
 t AS
 (
	SELECT 		
			date_trunc('second', timepoint)
	FROM 	activity_hist.archive_pg_stat_activity aa
	WHERE 	timepoint BETWEEN pg_stat_history_begin+(current_hour_diff * interval '1 hour') AND pg_stat_history_end+(current_hour_diff * interval '1 hour')  AND 
			( aa.wait_event_type IS NOT NULL  ) AND
			aa.state = 'active'
 )
 SELECT count(*) 
 INTO cpu_total
 FROM t ;

Приклад

CLUSTER WAITINGS TIME : 30:12:49

Total pg_stat_statements values

Запит

 --TOTAL pg_stat
  SELECT 
    SUM(calls) AS calls, SUM(total_time)  AS total_time, SUM(rows) AS rows ,
	SUM(shared_blks_hit)  AS shared_blks_hit,SUM(shared_blks_read) AS shared_blks_read ,
	SUM(shared_blks_dirtied) AS shared_blks_dirtied,SUM(shared_blks_written) AS shared_blks_written , 
    SUM(local_blks_hit) AS local_blks_hit , SUM(local_blks_read) AS local_blks_read , 
	SUM(local_blks_dirtied) AS local_blks_dirtied , SUM(local_blks_written)  AS local_blks_written,
	SUM(temp_blks_read) AS temp_blks_read, SUM(temp_blks_written) temp_blks_written , 
	SUM(blk_read_time) AS blk_read_time , SUM(blk_write_time) AS blk_write_time
  INTO 
    pg_total_stat_history_rec
  FROM 
    pg_stat_history
  WHERE 
 	snapshot_timestamp BETWEEN pg_stat_history_begin AND pg_stat_history_end AND 
	queryid IS NULL;

SQL DBTIME - загальний час виконання запитів

Запит

dbtime_total = interval '1 millisecond' * pg_total_stat_history_rec.total_time ;

Приклад

SQL DBTIME : 136:49:36

SQL CPU TIME-час CPU витрачений на виконання запитів

Запит

WITH 
 t AS
 (
	SELECT 		
			date_trunc('second', timepoint)
	FROM 	activity_hist.archive_pg_stat_activity aa
	WHERE 	timepoint BETWEEN pg_stat_history_begin+(current_hour_diff * interval '1 hour') AND pg_stat_history_end+(current_hour_diff * interval '1 hour')  AND 
			( aa.wait_event_type IS NULL  ) AND
			backend_type = 'client backend' AND 
			aa.state = 'active'
 )
 SELECT count(*) 
 INTO cpu_total
 FROM t ;

Приклад

SQL CPU TIME : 27:40:15

SQL WAITINGS TIME — загальний час очікувань для запитів

Запит

WITH 
 t AS
 (
	SELECT 		
			date_trunc('second', timepoint)
	FROM 	activity_hist.archive_pg_stat_activity aa
	WHERE 	timepoint BETWEEN pg_stat_history_begin+(current_hour_diff * interval '1 hour') AND pg_stat_history_end+(current_hour_diff * interval '1 hour')  AND 
			( aa.wait_event_type IS NOT NULL  ) AND
			aa.state = 'active' AND 
		backend_type = 'client backend'
 )
 SELECT count(*) 
 INTO waiting_total
 FROM t ;

Приклад

SQL WAITINGS TIME : 30:04:09

Наступні запити тривіальні й у економії місця деталі реалізації опускаются:

Приклад

| SQL IOTIME : 19:44:50
| SQL READ TIME : 19:44:32
| SQL WRITE TIME : 00:00:17
|
| SQL CALLS : 12188248
-------------------------------------------------------------
| SQL SHARED BLOCKS READS : 7997039120
| SQL SHARED BLOCKS HITS : 8868286092
| SQL SHARED BLOCKS HITS/READS % : 110.89
| SQL SHARED BLOCKS DIRTED : 419945
| SQL SHARED BLOCKS WRITTEN : 19857
|
| SQL TEMPORARY BLOCKS READS : 7836169
| SQL TEMPORARY BLOCKS WRITTEN : 10683938

Переходимо до найцікавішого розділу

WAITINGS STATICTICS

TOP 10 WAITINGS BY TOTAL WAIT TIME FOR CLIENTS PROCESSES

Запит

SELECT 
  wait_event_type , wait_event ,
  get_system_waiting_duration( wait_event_type , wait_event ,pg_stat_history_begin+(current_hour_diff * interval '1 hour') ,pg_stat_history_end+(current_hour_diff * interval '1 hour') ) as duration 
FROM
  activity_hist.archive_pg_stat_activity aa
WHERE 
  timepoint BETWEEN pg_stat_history_begin+(current_hour_diff * interval '1 hour') AND pg_stat_history_end+(current_hour_diff * interval '1 hour') AND backend_type != 'client backend' AND wait_event_type IS NOT NULL 
GROUP BY 
  wait_event_type, wait_event
ORDER BY 3 DESC
LIMIT 10

Приклад

+------------------------------------------------- ----------------------------------- | TOP 10 WAITINGS BY TOTAL WAIT TIME FOR SYSTEM PROCESSES +-----+------------------------------+-- ------------------+-------------------- | #| wait_event_type| wait_event | duration +-----+------------------------------+----------- ---------+-------------------- | 1| Activity| LogicalLauncherMain| 10:43:28 | 2| Activity| AutoVacuumMain| 10:42:49 | 3| Activity| WalWriterMain| 10:28:53 | 4| Activity| CheckpointerMain | 10:23:50 | 5| Activity| BgWriterMain | 09:11:59 | 6| Activity| BgWriterHibernate | 01:37:46 | 7| IO| BufFileWrite| 00:02:35 | 8| LWLock | buffer_mapping | 00:01:54 | 9| IO| DataFileRead| 00:01:23 | 10 | IO| WALWrite | 00:00:59 +-----+------------------------------+------- -------------+--------------------

TOP 10 WAITINGS BY TOTAL WAIT TIME FOR CLIENTS PROCESSES

Запит

SELECT 
  wait_event_type , wait_event ,
  get_clients_waiting_duration( wait_event_type , wait_event , pg_stat_history_begin+(current_hour_diff * interval '1 hour') , pg_stat_history_end+(current_hour_diff * interval '1 hour') ) as duration
FROM 
  activity_hist.archive_pg_stat_activity aa
WHERE 
  timepoint BETWEEN pg_stat_history_begin+(current_hour_diff * interval '1 hour') AND pg_stat_history_end+(current_hour_diff * interval '1 hour') AND backend_type = 'client backend' AND wait_event_type IS NOT NULL 
GROUP BY wait_event_type, wait_event
ORDER BY 3 DESC
LIMIT 10

Приклад

+-----+------------------------------+------------ --------+--------------------+---------- | #| wait_event_type| wait_event | тривалість | % dbtime +-----+------------------------------+---------- ----------+--------------------+---------- | 1| Lock| transactionid| 08:16:47| 6.05 | 2| IO| DataFileRead| 06:13:41| 4.55 | 3| Timeout| PgSleep | 02:53:21| 2.11 | 4| LWLock | buffer_mapping | 00:40:42| 0.5 | 5| LWLock | buffer_io| 00:17:17| 0.21 | 6| IO| BufFileWrite| 00:01:34| 0.02 | 7| Lock| tuple| 00:01:32| 0.02 | 8| Client| ClientRead| 00:01:19| 0.02 | 9| IO| BufFileRead| 00:00:37 | 0.01 | 10 | LWLock | buffer_content| 00:00:08 | 0 +-----+------------------------------+----------- ---------+--------------------+----------

WAITINGS TYPES BY TOTAL WAIT TIME, FOR SYSTEM PROCESSES

Запит

SELECT 
  wait_event_type ,
  get_system_waiting_type_duration( wait_event_type , pg_stat_history_begin+(current_hour_diff * interval '1 hour') , pg_stat_history_end+(current_hour_diff * interval '1 hour') ) as duration
FROM
  activity_hist.archive_pg_stat_activity aa
WHERE 
  timepoint BETWEEN pg_stat_history_begin+(current_hour_diff * interval '1 hour') AND pg_stat_history_end+(current_hour_diff * interval '1 hour') AND  backend_type != 'client backend' AND wait_event_type IS NOT NULL 
GROUP BY wait_event_type
ORDER BY 2 DESC

Приклад

+-----+------------------------------+------------ -------- | #| wait_event_type| duration +-----+------------------------------+----------- --------- | 1| Activity| 53:08:45 | 2| IO| 00:06:24 | 3| LWLock | 00:03:02 +-----+------------------------------+------- -------------

WAITINGS TYPES BY TOTAL WAIT TIME, FOR CLIENTS PROCESSES

Запит

SELECT 
  wait_event_type ,
  get_clients_waiting_type_duration( wait_event_type , pg_stat_history_begin+(current_hour_diff * interval '1 hour') , pg_stat_history_end+(current_hour_diff * interval '1 hour') ) as duration
FROM
  activity_hist.archive_pg_stat_activity aa
WHERE 
  timepoint BETWEEN pg_stat_history_begin+(current_hour_diff * interval '1 hour') AND pg_stat_history_end+(current_hour_diff * interval '1 hour') AND backend_type = 'client backend' AND wait_event_type IS NOT NULL 
GROUP BY wait_event_type
ORDER BY 2 DESC

Приклад

+-----+------------------------------+------------ --------+-------------------- | #| wait_event_type| тривалість | % dbtime +-----+------------------------------+---------- ----------+-------------------- | 1| Lock| 08:18:19| 6.07 | 2| IO| 06:16:01| 4.58 | 3| Timeout| 02:53:21| 2.11 | 4| LWLock | 00:58:12| 0.71 | 5| Client| 00:01:19| 0.02 | 6| IPC| 00:00:04 | 0 +-----+------------------------------+----------- ---------+--------------------

Тривалість очікувань для системних процесів та окремих запитів.

WAITINGS FOR SYSTEM PROCESSES

Запит

SELECT 
  backend_type , datname , wait_event_type , wait_event , get_backend_type_waiting_duration( backend_type , wait_event_type , wait_event , pg_stat_history_begin+(current_hour_diff * interval '1 hour') , pg_stat_history_end+(current_hour_diff * interval '1 hour') ) as duration 
FROM 
  activity_hist.archive_pg_stat_activity aa
WHERE 
  timepoint BETWEEN pg_stat_history_begin+(current_hour_diff * interval '1 hour') AND pg_stat_history_end+(current_hour_diff * interval '1 hour') AND backend_type != 'client backend' AND wait_event_type IS NOT NULL 
GROUP BY backend_type , datname , wait_event_type , wait_event
ORDER BY 5 DESC

Приклад

+-----+-----------------------------+----------+--------------------+----------------------+--------------------
|    #|                 backend_type|    dbname|     wait_event_type|            wait_event|            duration
+-----+-----------------------------+----------+--------------------+----------------------+--------------------
|    1| logical replication launcher|          |            Activity|   LogicalLauncherMain|            10:43:28
|    2|          autovacuum launcher|          |            Activity|        AutoVacuumMain|            10:42:49
|    3|                    walwriter|          |            Activity|         WalWriterMain|            10:28:53
|    4|                 checkpointer|          |            Activity|      CheckpointerMain|            10:23:50
|    5|            background writer|          |            Activity|          BgWriterMain|            09:11:59
|    6|            background writer|          |            Activity|     BgWriterHibernate|            01:37:46
|    7|              parallel worker|      tdb1|                  IO|          BufFileWrite|            00:02:35
|    8|              parallel worker|      tdb1|              LWLock|        buffer_mapping|            00:01:41
|    9|              parallel worker|      tdb1|                  IO|          DataFileRead|            00:01:22
|   10|              parallel worker|      tdb1|                  IO|           BufFileRead|            00:00:59
|   11|                    walwriter|          |                  IO|              WALWrite|            00:00:57
|   12|              parallel worker|      tdb1|              LWLock|             buffer_io|            00:00:47
|   13|            autovacuum worker|      tdb1|              LWLock|        buffer_mapping|            00:00:13
|   14|            background writer|          |                  IO|         DataFileWrite|            00:00:12
|   15|                 checkpointer|          |                  IO|         DataFileWrite|            00:00:11
|   16|                    walwriter|          |              LWLock|          WALWriteLock|            00:00:09
|   17|                 checkpointer|          |              LWLock|          WALWriteLock|            00:00:06
|   18|            background writer|          |              LWLock|          WALWriteLock|            00:00:06
|   19|                    walwriter|          |                  IO|          WALInitWrite|            00:00:02
|   20|            autovacuum worker|      tdb1|              LWLock|          WALWriteLock|            00:00:02
|   21|                    walwriter|          |                  IO|           WALInitSync|            00:00:02
|   22|            autovacuum worker|      tdb1|                  IO|          DataFileRead|            00:00:01
|   23|                 checkpointer|          |                  IO| ControlFileSyncUpdate|            00:00:01
|   24|            background writer|          |                  IO|              WALWrite|            00:00:01
|   25|            background writer|          |                  IO|         DataFileFlush|            00:00:01
|   26|                 checkpointer|          |                  IO|         SLRUFlushSync|            00:00:01
|   27|            autovacuum worker|      tdb1|                  IO|              WALWrite|            00:00:01
|   28|                 checkpointer|          |                  IO|          DataFileSync|            00:00:01
+-----+-----------------------------+----------+--------------------+----------------------+--------------------

WAITINGS FOR SQL — очікування окремих запитів по queryid

Запит

SELECT 
queryid , datname , wait_event_type , wait_event , get_query_waiting_duration( queryid ,  wait_event_type , wait_event , pg_stat_history_begin+(current_hour_diff * interval '1 hour') , pg_stat_history_end+(current_hour_diff * interval '1 hour') ) as duration 
FROM 
  activity_hist.archive_pg_stat_activity aa
WHERE 
  timepoint BETWEEN pg_stat_history_begin+(current_hour_diff * interval '1 hour') AND pg_stat_history_end+(current_hour_diff * interval '1 hour') AND backend_type = 'client backend' AND wait_event_type IS NOT NULL AND queryid IS NOT NULL 
GROUP BY queryid , datname , wait_event_type , wait_event
ORDER BY 1 , 5 DESC 

Приклад

+-----+-------------------------+----------+--------------------+--------------------+--------------------+--------------------
|    #|                  queryid|    dbname|     wait_event_type|          wait_event|            waitings|               total
|     |                         |          |                    |                    |            duration|            duration
+-----+-------------------------+----------+--------------------+--------------------+--------------------+--------------------
|    1|     -8247416849404883188|      tdb1|              Client|          ClientRead|            00:00:02|
|    2|     -6572922443698419129|      tdb1|              Client|          ClientRead|            00:00:05|
|    3|     -6572922443698419129|      tdb1|                  IO|        DataFileRead|            00:00:01|
|    4|     -5917408132400665328|      tdb1|              Client|          ClientRead|            00:00:04|
|    5|     -4091009262735781873|      tdb1|              Client|          ClientRead|            00:00:03|
|    6|     -1473395109729441239|      tdb1|              Client|          ClientRead|            00:00:01|
|    7|        28942442626229688|      tdb1|                  IO|        BufFileWrite|            00:01:34|            00:46:06
|    8|        28942442626229688|      tdb1|              LWLock|      buffer_mapping|            00:01:05|            00:46:06
|    9|        28942442626229688|      tdb1|                  IO|        DataFileRead|            00:00:44|            00:46:06
|   10|        28942442626229688|      tdb1|                  IO|         BufFileRead|            00:00:37|            00:46:06
|   11|        28942442626229688|      tdb1|              LWLock|           buffer_io|            00:00:35|            00:46:06
|   12|        28942442626229688|      tdb1|              Client|          ClientRead|            00:00:05|            00:46:06
|   13|        28942442626229688|      tdb1|                 IPC| MessageQueueReceive|            00:00:03|            00:46:06
|   14|        28942442626229688|      tdb1|                 IPC|    BgWorkerShutdown|            00:00:01|            00:46:06
|   15|       389015618226997618|      tdb1|                Lock|       transactionid|            03:55:09|            04:14:15
|   16|       389015618226997618|      tdb1|                  IO|        DataFileRead|            03:23:09|            04:14:15
|   17|       389015618226997618|      tdb1|              LWLock|      buffer_mapping|            00:12:09|            04:14:15
|   18|       389015618226997618|      tdb1|              LWLock|           buffer_io|            00:10:18|            04:14:15
|   19|       389015618226997618|      tdb1|                Lock|               tuple|            00:00:35|            04:14:15
|   20|       389015618226997618|      tdb1|              LWLock|        WALWriteLock|            00:00:02|            04:14:15
|   21|       389015618226997618|      tdb1|                  IO|       DataFileWrite|            00:00:01|            04:14:15
|   22|       389015618226997618|      tdb1|              LWLock|        SyncScanLock|            00:00:01|            04:14:15
|   23|       389015618226997618|      tdb1|              Client|          ClientRead|            00:00:01|            04:14:15
|   24|       734234407411547467|      tdb1|              Client|          ClientRead|            00:00:11|
|   25|       734234407411547467|      tdb1|              LWLock|      buffer_mapping|            00:00:05|
|   26|       734234407411547467|      tdb1|                  IO|        DataFileRead|            00:00:02|
|   27|      1237430309438971376|      tdb1|              LWLock|      buffer_mapping|            00:02:18|            02:45:40
|   28|      1237430309438971376|      tdb1|                  IO|        DataFileRead|            00:00:27|            02:45:40
|   29|      1237430309438971376|      tdb1|              Client|          ClientRead|            00:00:02|            02:45:40
|   30|      2404820632950544954|      tdb1|              Client|          ClientRead|            00:00:01|
|   31|      2515308626622579467|      tdb1|              Client|          ClientRead|            00:00:02|
|   32|      4710212362688288619|      tdb1|              LWLock|      buffer_mapping|            00:03:08|            02:18:21
|   33|      4710212362688288619|      tdb1|                  IO|        DataFileRead|            00:00:22|            02:18:21
|   34|      4710212362688288619|      tdb1|              Client|          ClientRead|            00:00:06|            02:18:21
|   35|      4710212362688288619|      tdb1|              LWLock|           buffer_io|            00:00:02|            02:18:21
|   36|      9150846928388977274|      tdb1|                  IO|        DataFileRead|            00:01:19|
|   37|      9150846928388977274|      tdb1|              LWLock|      buffer_mapping|            00:00:34|
|   38|      9150846928388977274|      tdb1|              Client|          ClientRead|            00:00:10|
|   39|      9150846928388977274|      tdb1|              LWLock|           buffer_io|            00:00:01|
+-----+-------------------------+----------+--------------------+--------------------+--------------------+--------------------

CLIENT SQL STATICTICS - TOP запитів

Запити отримання знову, таки тривіальні й у економії місця, не наводяться.

Приклади

+------------------------------------------------------------------------------------
| CLIENT SQL ordered by Elapsed Time
+--------------------+----------+----------+----------+----------+----------+--------------------
|        elapsed time|     calls|  % dbtime|     % CPU|      % IO|    dbname|             queryid
+--------------------+----------+----------+----------+----------+----------+--------------------
|            04:14:15|        19|       3.1|     10.83|     11.52|      tdb1|  389015618226997618
|            02:45:40|       746|      2.02|      4.23|      0.08|      tdb1| 1237430309438971376
|            02:18:21|       749|      1.69|      3.39|       0.1|      tdb1| 4710212362688288619
|            00:46:06|       375|      0.56|      0.94|      0.41|      tdb1|   28942442626229688
+--------------------+----------+----------+----------+----------+----------+--------------------
| CLIENT SQL ordered by CPU Time
+--------------------+----------+----------+----------+----------+----------+----------+--------------------
|            cpu time|     calls|  % dbtime|total_time|     % CPU|      % IO|    dbname|             queryid
+--------------------+----------+----------+----------+----------+----------+----------+--------------------
|            02:59:49|        19|       3.1|  04:14:15|     10.83|     11.52|      tdb1|  389015618226997618
|            01:10:12|       746|      2.02|  02:45:40|      4.23|      0.08|      tdb1| 1237430309438971376
|            00:56:15|       749|      1.69|  02:18:21|      3.39|       0.1|      tdb1| 4710212362688288619
|            00:15:35|       375|      0.56|  00:46:06|      0.94|      0.41|      tdb1|   28942442626229688
+--------------------+----------+----------+----------+----------+----------+----------+--------------------
| CLIENT SQL ordered by User I/O Wait Time
+--------------------+----------+----------+----------+----------+----------+----------+--------------------
|        io_wait time|     calls|  % dbtime|total_time|     % CPU|      % IO|    dbname|             queryid
+--------------------+----------+----------+----------+----------+----------+----------+--------------------
|            03:23:10|        19|       3.1|  04:14:15|     10.83|     11.52|      tdb1|  389015618226997618
|            00:02:54|       375|      0.56|  00:46:06|      0.94|      0.41|      tdb1|   28942442626229688
|            00:00:27|       746|      2.02|  02:45:40|      4.23|      0.08|      tdb1| 1237430309438971376
|            00:00:22|       749|      1.69|  02:18:21|      3.39|       0.1|      tdb1| 4710212362688288619
+--------------------+----------+----------+----------+----------+----------+----------+--------------------
| CLIENT SQL ordered by Shared Buffers Reads
+--------------------+----------+----------+----------+----------+----------+----------+--------------------
|       buffers reads|     calls|  % dbtime|total_time|     % CPU|      % IO|    dbname|             queryid
+--------------------+----------+----------+----------+----------+----------+----------+--------------------
|          1056388566|        19|       3.1|  04:14:15|     10.83|     11.52|      tdb1|  389015618226997618
|            11709251|       375|      0.56|  00:46:06|      0.94|      0.41|      tdb1|   28942442626229688
|             3439004|       746|      2.02|  02:45:40|      4.23|      0.08|      tdb1| 1237430309438971376
|             3373330|       749|      1.69|  02:18:21|      3.39|       0.1|      tdb1| 4710212362688288619
+--------------------+----------+----------+----------+----------+----------+----------+--------------------
| CLIENT SQL ordered by Disk Reads Time
+--------------------+----------+----------+----------+----------+----------+----------+--------------------
|           read time|     calls|  % dbtime|total_time|     % CPU|      % IO|    dbname|             queryid
+--------------------+----------+----------+----------+----------+----------+----------+--------------------
|            02:16:30|        19|       3.1|  04:14:15|     10.83|     11.52|      tdb1|  389015618226997618
|            00:04:50|       375|      0.56|  00:46:06|      0.94|      0.41|      tdb1|   28942442626229688
|            00:01:10|       749|      1.69|  02:18:21|      3.39|       0.1|      tdb1| 4710212362688288619
|            00:00:57|       746|      2.02|  02:45:40|      4.23|      0.08|      tdb1| 1237430309438971376
+--------------------+----------+----------+----------+----------+----------+----------+--------------------
| CLIENT SQL ordered by Executions
+--------------------+----------+----------+----------+----------+----------+----------+--------------------
|               calls|      rows|  % dbtime|total_time|     % CPU|      % IO|    dbname|             queryid
+--------------------+----------+----------+----------+----------+----------+----------+--------------------
|                 749|       749|      1.69|  02:18:21|      3.39|       0.1|      tdb1| 4710212362688288619
|                 746|       746|      2.02|  02:45:40|      4.23|      0.08|      tdb1| 1237430309438971376
|                 375|         0|      0.56|  00:46:06|      0.94|      0.41|      tdb1|   28942442626229688
|                  19|        19|       3.1|  04:14:15|     10.83|     11.52|      tdb1|  389015618226997618
+--------------------+----------+----------+----------+----------+----------+----------+--------------------

Підсумок

Використовуючи подані запити та одержувану звітність, можна отримувати більш повну картину для аналізу та вирішення проблем деградації продуктивності за окремими запитами та всього кластера, загалом.

Розвиток

Поки що плани на розвиток такі:

  • Доповнити звітність історією блокувань. Запити тестуються та будуть представлені найближчим часом.
  • Використовувати розширення TimescaleDB для зберігання історії pg_stat_activity та pg_locks.
  • Підготувати пакетне рішення на github для масового розгортання на базах продакшн.

Далі буде ...

Джерело: habr.com

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