🥇 Eng vun de Methoden fir d'Spärgeschicht am PostgreSQL

Fortsetzung vum Artikel "E Versuch en Analog vun ASH fir PostgreSQL ze kreéieren ".

Den Artikel wäert betruecht a weisen op spezifesch Ufroen a Beispiller wat nëtzlech Informatioune kann mat der pg_locks View Geschicht kritt ginn.

Warnung
Wéinst der Neiheet vum Thema an der Onvollstännegkeet vun der Testperiod kann den Artikel Feeler enthalen. Kritik a Kommentare si wëllkomm an erwaart.

Input Daten

pg_locks Representatioun Geschicht

archive_locking

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 
);

Prinzipiell ass den Dësch ähnlech wéi den Dësch archive_pg_stat_activityhei méi detailléiert beschriwwen - pg_stat_statements + pg_stat_activity + loq_query = pg_ash? an hei - E Versuch en Analog vun ASH fir PostgreSQL ze kreéieren.

Fir eng Kolonn ze fëllen queryid Funktioun benotzt gëtt

update_history_locking_by_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;

Erklärung: de Wäert vun der Queryid Kolonn gëtt an der History_locking Tabell aktualiséiert, an dann wann eng nei Partition fir den Archive_locking Dësch erstallt gëtt, gëtt de Wäert an historesche Wäerter gespäichert.

Ausgang

Allgemeng Informatiounen iwwert Prozesser am Allgemengen.

WAARDEN FIR LOCK BY LOCKTYPES

Ufro

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

Beispill:

| WAARDEN OP SLÉISSER VUN LOCKTYPES +-------------------------+------------------------------------- -------+--------------------- | locktype| Modus| Dauer +-------------------------- ------------------ | transaktionid| deelen| 19:39:26 | tupp| AccessExclusiveLock| 00:03:35 +-------------------- -------+---------------------

TAKEN VUN LOCK BY LOCKTYPES

Ufro

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

Beispill:

| TAKEN VUN SCHLOSSEN VUN SCHLOSSTYPEN +-------------------------+------------------------------------ -------+--------------------- | locktype| Modus| Dauer +-------------------------- ------------------ | Relatioun| RowExclusiveLock| 51:11:10 | virtualxid| ExklusivSpär| 48:10:43 | transaktionid| ExklusivSpär| 44:24:53 | Relatioun| AccessShareLock| 20:06:13 | tupp| AccessExclusiveLock| 17:58:47 | tupp| ExklusivSpär| 01:40:41 | Relatioun| ShareUpdateExclusiveLock| 00:26:41 | Objet| RowExclusiveLock| 00:00:01 | transaktionid| deelen| 00:00:01 | verlängeren| ExklusivSpär| 00:00:01 +--------------------- -------+---------------------

Detailléiert Informatioun fir spezifesch Queryid Ufroen

WAARDE FIR LOCK BY LOCKTYPES BY QUERYID

Ufro

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

Beispill:

| WAARDEN OP SLÉISSER VUN LOCKTYPES VUN QUERYID +----------+--------------------------+----- ---------------+------------------- ------------------+---------------------+ ---------- | pidd| locktype| Modus| ugefaangen| queryid| blocking_pids| Dauer +-------------------- ------------------------------------- ---+----------------------------+---------------- --- | 11288| transaktionid| deelen| 2019-09-17 10:00:00.302936| 389015618226997618| {11092}| 00:03:34 | 11626| transaktionid| deelen| 2019-09-17 10:00:21.380921| 389015618226997618| {12380}| 00:00:29 | 11626| transaktionid| deelen| 2019-09-17 10:00:21.380921| 389015618226997618| {11092}| 00:03:25 | 11626| transaktionid| deelen| 2019-09-17 10:00:21.380921| 389015618226997618| {12213}| 00:01:55 | 11626| transaktionid| deelen| 2019-09-17 10:00:21.380921| 389015618226997618| {12751}| 00:00:01 | 11629| transaktionid| deelen| 2019-09-17 10:00:24.331935| 389015618226997618| {11092}| 00:03:22 | 11629| transaktionid| deelen| 2019-09-17 10:00:24.331935| 389015618226997618| {12007}| 00:00:01 | 12007| transaktionid| deelen| 2019-09-17 10:05:03.327933| 389015618226997618| {11629}| 00:00:13 | 12007| transaktionid| deelen| 2019-09-17 10:05:03.327933| 389015618226997618| {11092}| 00:01:10 | 12007| transaktionid| deelen| 2019-09-17 10:05:03.327933| 389015618226997618| {11288}| 00:00:05 | 12213| transaktionid| deelen| 2019-09-17 10:06:07.328019| 389015618226997618| {12007}| 00:00:10

HUELEN LOCK BY LOCKTYPES BY QUERYID

Ufro

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

Beispill:

| LOCKTYPES VUN QUERYID NEMEN +----------------------------- --------------+-------------------- --+----------------------------+------------------------ | pidd| locktype| Modus| ugefaangen| queryid| blocking_pids| Dauer +-------------------- ------------------------------------- ---+----------------------------+---------------- --- | 11288| Relatioun| RowExclusiveLock| 2019-09-17 10:00:00.302936| 389015618226997618| {11092}| 00:03:34 | 11092 2019| transaktionid| ExklusivSpär| 09-17-10 00:00.302936:389015618226997618| 00| {}| 03:34:11288 | 2019| Relatioun| RowExclusiveLock| 09-17-10 00:00.302936:389015618226997618| 00| {}| 00:10:11092 | 2019 09| Relatioun| RowExclusiveLock| 17-10-00 00.302936:389015618226997618:00| 03| {}| 34:11092:2019 | 09 17| virtualxid| ExklusivSpär| 10-00-00.302936 389015618226997618:00:03| 34| {}| 11288:2019:09 | 17| virtualxid| ExklusivSpär| 10-00-00.302936 389015618226997618:11092:00| 03| {34}| 11288:2019:09 | 17| transaktionid| ExklusivSpär| 10-00-00.302936 389015618226997618:11092:00| 03| {34}| 11288:2019:09 | 17| tupp| AccessExclusiveLock| 10-00-00.302936 389015618226997618:11092:00| 03| {34}| XNUMX:XNUMX:XNUMX

Benotzt d'Blockéierungsgeschicht wann Dir Performance Tëschefäll analyséiert.

Eng Ufro mat queryid=389015618226997618 ausgefouert vun engem Prozess mat pid=11288 huet zënter 2019-09-17 10:00:00 fir 3 Minutten op e Spär gewaart.
D'Spär gouf vun engem Prozess mat pid = 11092 ofgehalen
E Prozess mat pid=11092 déi eng Ufro ausféiert mat queryid=389015618226997618 zënter 2019-09-17 10:00:00 huet d'Spär fir 3 Minutten gehal.

D 'Resultat

Elo, hoffen ech, wäert déi interessantst an nëtzlech Saach ufänken - Statistiken sammelen an analyséieren Fäll iwwer d'Geschicht vun Erwaardungen a Spären.

An Zukunft, géif ech gär gleewen, Dir kritt e Set vun enger Aart Notiz (ähnlech wéi dem Oracle's Metalink).

Am Allgemengen ass et aus dësem Grond datt d'Methodologie déi benotzt gëtt sou séier wéi méiglech fir d'ëffentlech Bekanntschaft ugewise gëtt.

An der ganz noer Zukunft wäert ech probéieren de Projet op github ze setzen.

Source: will.com

Eng vun de Methoden fir Spärgeschicht am PostgreSQL ze kréien

Input Daten

pg_locks Representatioun Geschicht

Ausgang

WAARDEN FIR LOCK BY LOCKTYPES

TAKEN VUN LOCK BY LOCKTYPES

WAARDE FIR LOCK BY LOCKTYPES BY QUERYID

HUELEN LOCK BY LOCKTYPES BY QUERYID

D 'Resultat

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