Unu el la metodoj por akiri serurhistorion en PostgreSQL

Daŭrigo de la artikolo "Provo krei ASH-analogon por PostgreSQL ".

La artikolo ekzamenos kaj montros, uzante specifajn demandojn kaj ekzemplojn, kiajn utilajn informojn oni povas akiri uzante la historion de la vido pg_locks.

Averto.
Pro la noveco de la temo kaj la nefinita testa periodo, la artikolo povas enhavi erarojn. Kritiko kaj komentoj estas forte bonvenataj kaj atendataj.

Eniga datumoj

Historio de pg_locks reprezentado

arĥivo_ŝlosado

CREATE TABLE archive_locking 
(       timepoint timestamp without time zone ,
	locktype text ,
	relation oid ,
	mode text ,
	tid xid ,
	vtid text ,
	pid integer ,
	blocking_pids integer[] ,
	granted boolean ,
        queryid bigint 
);

Esence, la tablo estas simila al la tablo archive_pg_stat_activity, priskribita pli detale ĉi tie - pg_stat_statements + pg_stat_activity + loq_query = pg_ash? kaj ĉi tie - Provo krei analogon de ASH por PostgreSQL.

Por plenigi kolumnon queryid funkcio estas uzata

ĝisdatigo_historio_ŝlosado_per_queryid

--update_history_locking_by_queryid.sql
CREATE OR REPLACE FUNCTION update_history_locking_by_queryid() RETURNS boolean AS $$
DECLARE
  result boolean ;
  current_minute double precision ; 
  
  start_minute integer ;
  finish_minute integer ;
  
  start_period timestamp without time zone ;
  finish_period timestamp without time zone ;
  
  lock_rec record ; 
  endpoint_rec record ; 
  
  current_hour_diff double precision ;
BEGIN
  RAISE NOTICE '***update_history_locking_by_queryid';
  
  result = TRUE ;
  
  current_minute = extract ( minute from now() );

  SELECT * FROM endpoint WHERE is_need_monitoring
  INTO endpoint_rec ;
  
  current_hour_diff = endpoint_rec.hour_diff ;
  
  IF current_minute < 5 
  THEN
	RAISE NOTICE 'Current time is less than 5 minute.';
	
	start_period = date_trunc('hour',now()) + (current_hour_diff * interval '1 hour');
    finish_period = start_period - interval '5 minute' ;
  ELSE 
    finish_minute =  extract ( minute from now() ) / 5 ;
    start_minute =  finish_minute - 1 ;
  
    start_period = date_trunc('hour',now()) + interval '1 minute'*start_minute*5+(current_hour_diff * interval '1 hour');
    finish_period = date_trunc('hour',now()) + interval '1 minute'*finish_minute*5+(current_hour_diff * interval '1 hour') ;
    
  END IF ;  
  
  RAISE NOTICE 'start_period = %', start_period;
  RAISE NOTICE 'finish_period = %', finish_period;

	FOR lock_rec IN   
	WITH act_queryid AS
	 (
		SELECT 
				pid , 
				timepoint ,
				query_start AS started ,			
				MAX(timepoint) OVER (PARTITION BY pid ,	query_start   ) AS finished ,			
				queryid 
		FROM 
				activity_hist.history_pg_stat_activity 			
		WHERE 			
				timepoint BETWEEN start_period and 
								  finish_period
		GROUP BY 
				pid , 
				timepoint ,  
				query_start ,
				queryid 
	 ),
	 lock_pids AS
		(
			SELECT
				hl.pid , 
				hl.locktype  ,
				hl.mode ,
				hl.timepoint , 
				MIN ( timepoint ) OVER (PARTITION BY pid , locktype  ,mode ) as started 
			FROM 
				activity_hist.history_locking hl
			WHERE 
				hl.timepoint between start_period and 
								     finish_period
			GROUP BY 
				hl.pid , 
				hl.locktype  ,
				hl.mode ,
				hl.timepoint 
		)
	SELECT 
		lp.pid , 
		lp.locktype  ,
		lp.mode ,
		lp.timepoint ,     
		aq.queryid 
	FROM lock_pids 	lp LEFT OUTER JOIN act_queryid aq ON ( lp.pid = aq.pid AND lp.started BETWEEN aq.started AND aq.finished )
	WHERE aq.queryid IS NOT NULL 
	GROUP BY  
		lp.pid , 
		lp.locktype  ,
		lp.mode ,
		lp.timepoint , 
		aq.queryid
	LOOP
		UPDATE activity_hist.history_locking SET queryid = lock_rec.queryid 
		WHERE pid = lock_rec.pid AND locktype = lock_rec.locktype AND mode = lock_rec.mode AND timepoint = lock_rec.timepoint ;	
	END LOOP;    
  
  RETURN result ;
END
$$ LANGUAGE plpgsql;

Klarigo: la valoro de la queryid-kolumno estas ĝisdatigita en la history_locking-tabelo, kaj tiam kiam nova sekcio estas kreita por la archive_locking-tabelo, la valoro estos konservita en la historiaj valoroj.

Eligo

Ĝeneralaj informoj pri procezoj ĝenerale.

ATENDAS SERUROJ PER SERRUTIPOJ

Peto

WITH
t AS
(
	SELECT 
		locktype  ,
		mode ,
		count(*) as total 
	FROM 
		activity_hist.archive_locking
	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 
		NOT granted
	GROUP BY 
		locktype  ,
		mode  
)
SELECT 
	locktype  ,
	mode ,
	total * interval '1 second' as duration			
FROM t 		
ORDER BY 3 DESC 

Ekzemplo:

| ATENDAS SERUROJ PER SERRUTIPOJ +-----------+---------------------- --------+ ------------------- | serurotipo| reĝimo| daŭro +--------------------+-------------------------- --+-------------------- | transakciid| ShareLock| 19:39:26 | opo| AccessExclusiveLock| 00:03:35 +-------------------+----------------------- - -------+----------

PRENOJ DE SERUROJ PER SERRUTIPOJ

Peto

WITH
t AS
(
	SELECT 
		locktype  ,
		mode ,
		count(*) as total 
	FROM 
		activity_hist.archive_locking
	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 
		granted
	GROUP BY 
		locktype  ,
		mode  
)
SELECT 
	locktype  ,
	mode ,
	total * interval '1 second' as duration			
FROM t 		
ORDER BY 3 DESC 

Ekzemplo:

| PRENOJ DE SERUROJ PER SERRUTIPOJ +--------------------+----------------------- --------+------------------- | serurotipo| reĝimo| daŭro +--------------------+-------------------------- --+-------------------- | rilato| RowExclusiveLock| 51:11:10 | virtualxid| Ekskluziva Ŝlosilo| 48:10:43 | transakciid| Ekskluziva Ŝlosilo| 44:24:53 | rilato| AccessShareLock| 20:06:13 | opo| AccessExclusiveLock| 17:58:47 | opo| Ekskluziva Ŝlosilo| 01:40:41 | rilato| ShareUpdateExclusiveLock| 00:26:41 | objekto| RowExclusiveLock| 00:00:01 | transakciid| ShareLock| 00:00:01 | etendi| Ekskluziva Ŝlosilo| 00:00:01 +-------------------+----------------------- - -------+----------

Detalaj informoj pri specifaj queryid-petoj

ATENDAS SERRUĴOJ PER SERRUTIPOJ PER QUERYID

Peto

WITH
lt AS
(
	SELECT
		pid , 
		locktype  ,
		mode ,
		timepoint , 
		queryid , 
		blocking_pids ,
                MIN ( timepoint ) OVER (PARTITION BY pid , locktype  ,mode ) as started  
	FROM 
		activity_hist.archive_locking
	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 
		NOT granted AND
	       queryid IS NOT NULL 
	GROUP BY 
	        pid , 
		locktype  ,
		mode ,
		timepoint ,
		queryid ,
		blocking_pids 
)
SELECT 
        lt.pid , 
	lt.locktype  ,
	lt.mode ,			
        lt.started ,
	lt.queryid  ,
	lt.blocking_pids ,
	COUNT(*)  * interval '1 second'	 as duration		
FROM lt 	
GROUP BY 
	lt.pid , 
        lt.locktype  ,
	lt.mode ,			
        lt.started ,
        lt.queryid ,
	lt.blocking_pids 
ORDER BY 4

Ekzemplo:

| ATENDAS SERUROJ PER SERRUTIPOJ PER QUERYID +----------+----------+----- ---------------- +----------------------------+--- ----------------- -+--------------------+----------- ---------- | pid| serurotipo| reĝimo| komencis| queryid| blokado_pidoj| daŭro +----------+------------------------+----------- ---------+-----------------------------+--------- -----------+--------------------+----------------- --- | 11288| transakciid| ShareLock| 2019-09-17 10:00:00.302936| 389015618226997618| {11092}| 00:03:34 | 11626| transakciid| ShareLock| 2019-09-17 10:00:21.380921| 389015618226997618| {12380}| 00:00:29 | 11626| transakciid| ShareLock| 2019-09-17 10:00:21.380921| 389015618226997618| {11092}| 00:03:25 | 11626| transakciid| ShareLock| 2019-09-17 10:00:21.380921| 389015618226997618| {12213}| 00:01:55 | 11626| transakciid| ShareLock| 2019-09-17 10:00:21.380921| 389015618226997618| {12751}| 00:00:01 | 11629| transakciid| ShareLock| 2019-09-17 10:00:24.331935| 389015618226997618| {11092}| 00:03:22 | 11629| transakciid| ShareLock| 2019-09-17 10:00:24.331935| 389015618226997618| {12007}| 00:00:01 | 12007| transakciid| ShareLock| 2019-09-17 10:05:03.327933| 389015618226997618| {11629}| 00:00:13 | 12007| transakciid| ShareLock| 2019-09-17 10:05:03.327933| 389015618226997618| {11092}| 00:01:10 | 12007| transakciid| ShareLock| 2019-09-17 10:05:03.327933| 389015618226997618| {11288}| 00:00:05 | 12213| transakciid| ShareLock| 2019-09-17 10:06:07.328019| 389015618226997618| {12007}| 00:00:10

PRI SERUROJ PER SERRUTIPOJ PER QUERYID

Peto

WITH
lt AS
(
	SELECT
		pid , 
		locktype  ,
		mode ,
		timepoint , 
		queryid , 
		blocking_pids ,
                MIN ( timepoint ) OVER (PARTITION BY pid , locktype  ,mode ) as started  
	FROM 
		activity_hist.archive_locking
	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 
		granted AND
		queryid IS NOT NULL 
	GROUP BY 
	        pid , 
		locktype  ,
		mode ,
		timepoint ,
		queryid ,
		blocking_pids 
)
SELECT 
        lt.pid , 
	lt.locktype  ,
	lt.mode ,			
        lt.started ,
	lt.queryid  ,
	lt.blocking_pids ,
	COUNT(*)  * interval '1 second'	 as duration			
FROM lt 	
GROUP BY 
	lt.pid , 
	lt.locktype  ,
	lt.mode ,			
        lt.started ,
	lt.queryid ,
	lt.blocking_pids 
ORDER BY 4

Ekzemplo:

| PRENO DE SERUROJ PER SERRUTIPOJ PER QUERYID +----------+----------+------ --------------+ ----------------------------+---- ----------------+ --------------------+------------ -------- | pid| serurotipo| reĝimo| komencis| queryid| blokado_pidoj| daŭro +----------+------------------------+----------- ---------+-----------------------------+--------- -----------+--------------------+----------------- --- | 11288| rilato| RowExclusiveLock| 2019-09-17 10:00:00.302936| 389015618226997618| {11092}| 00:03:34 | 11092| transakciid| Ekskluziva Ŝlosilo| 2019-09-17 10:00:00.302936| 389015618226997618| {}| 00:03:34 | 11288| rilato| RowExclusiveLock| 2019-09-17 10:00:00.302936| 389015618226997618| {}| 00:00:10 | 11092| rilato| RowExclusiveLock| 2019-09-17 10:00:00.302936| 389015618226997618| {}| 00:03:34 | 11092| virtualxid| Ekskluziva Ŝlosilo| 2019-09-17 10:00:00.302936| 389015618226997618| {}| 00:03:34 | 11288| virtualxid| Ekskluziva Ŝlosilo| 2019-09-17 10:00:00.302936| 389015618226997618| {11092}| 00:03:34 | 11288| transakciid| Ekskluziva Ŝlosilo| 2019-09-17 10:00:00.302936| 389015618226997618| {11092}| 00:03:34 | 11288| opo| AccessExclusiveLock| 2019-09-17 10:00:00.302936| 389015618226997618| {11092}| 00:03:34

Uzante ŝlosilhistorion por analizi agadojn okazaĵojn.

  1. Peto kun queryid=389015618226997618 efektivigita de procezo kun pid=11288 atendis blokadon ekde 2019-09-17 10:00:00 dum 3 minutoj.
  2. La seruro estis tenita per procezo kun pid=11092
  3. Procezo kun pid=11092 plenumanta peton kun queryid=389015618226997618 ekde 2019-09-17 10:00:00 tenis la seruron dum 3 minutoj.

La rezulto

Nun, mi esperas, komenciĝos la plej interesa kaj utila parto - kolekti statistikojn kaj analizi kazojn pri la historio de atendoj kaj blokadoj.

Estonte, mi volas kredi, ni ricevos aron da kelkaj notoj (similaj al la metaligo de Oracle).

Ĝenerale, tial la uzata metodaro estas disponebla al ĉiuj kiel eble plej rapide.

Mi provos afiŝi la projekton sur github baldaŭ.

fonto: www.habr.com

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