🥇Een van die metodes om slotgeskiedenis in PostgreSQL te verkry

Voortsetting van die artikel "'n Poging om 'n ASH-analoog vir PostgreSQL te skep «.

Die artikel sal ondersoek en wys, met behulp van spesifieke navrae en voorbeelde, watter nuttige inligting verkry kan word deur die geskiedenis van die pg_locks-aansig te gebruik.

Waarskuwing.
As gevolg van die nuutheid van die onderwerp en die onvoltooide toetsperiode, kan die artikel foute bevat. Kritiek en kommentaar word sterk verwelkom en verwag.

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Geskiedenis van pg_locks voorstelling

argief_sluiting

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 
);

In wese is die tabel soortgelyk aan die tabel argief_pg_stat_aktiwiteit, hier in meer besonderhede beskryf - pg_stat_statements + pg_stat_activity + loq_query = pg_ash? en hier - 'n Poging om 'n analoog van ASH vir PostgreSQL te skep.

Om 'n kolom te vul queryid funksie gebruik word

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;

Verduideliking: die waarde van die queryid-kolom word opgedateer in die history_locking-tabel, en wanneer 'n nuwe partisie vir die archive_locking-tabel geskep word, sal die waarde in die historiese waardes gestoor word.

Uitset

Algemene inligting oor prosesse in die algemeen.

WAG VIR SLUITE DEUR SLOTTIPE

Navraag

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

Voorbeeld

| WAG VIR SLOTE DEUR SLOTTIPE +-----------+------------------------------------------+ ------------------ | slottipe| modus| duur +---------------------+-------------------------------- - --+---------------------------- | transaksieid| DeelSlot| 19:39:26 | tupel| AccessExclusive Lock| 00:03:35 +--------------------+-------------------------------- - -------+----------

OPNAME VAN SLUITE PER SLOTTIPE

Navraag

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

Voorbeeld

| OPNAME VAN SLOTE PER SLOTTIPE +-------------------+------------------------------ ----+------------------------- | slottipe| modus| duur +---------------------+-------------------------------- - --+---------------------------- | verhouding| RowExclusiveLock| 51:11:10 | virtualxid| EksklusieweSlot| 48:10:43 | transaksieid| EksklusieweSlot| 44:24:53 | verhouding| AccessShareLock| 20:06:13 | tupel| AccessExclusive Lock| 17:58:47 | tupel| EksklusieweSlot| 01:40:41 | verhouding| DeelUpdateExclusiveLock| 00:26:41 | voorwerp| RowExclusiveLock| 00:00:01 | transaksieid| DeelSlot| 00:00:01 | verleng| EksklusieweSlot| 00:00:01 +--------------------+----------------------------- - -------+----------

Gedetailleerde inligting oor spesifieke queryid-versoeke

WAG VIR SLUITE DEUR SLOTTIPE DEUR QUERYID

Navraag

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

Voorbeeld

| WAG VIR SLUITE DEUR SLOTTIPE DEUR QUERYID +--------------------------- +----------------------------+--- ------------------ --+--------------------+---------------- ---------- | pid| slottipe| modus| begin| navraag| blocking_pids| duur +----------+--------------------------------+---------------- ----------+-------------------------------------+--------- ----------------------------------+ --- | 11288| transaksieid| DeelSlot| 2019-09-17 10:00:00.302936| 389015618226997618| {11092}| 00:03:34 | 11626| transaksieid| DeelSlot| 2019-09-17 10:00:21.380921| 389015618226997618| {12380}| 00:00:29 | 11626| transaksieid| DeelSlot| 2019-09-17 10:00:21.380921| 389015618226997618| {11092}| 00:03:25 | 11626| transaksieid| DeelSlot| 2019-09-17 10:00:21.380921| 389015618226997618| {12213}| 00:01:55 | 11626| transaksieid| DeelSlot| 2019-09-17 10:00:21.380921| 389015618226997618| {12751}| 00:00:01 | 11629| transaksieid| DeelSlot| 2019-09-17 10:00:24.331935| 389015618226997618| {11092}| 00:03:22 | 11629| transaksieid| DeelSlot| 2019-09-17 10:00:24.331935| 389015618226997618| {12007}| 00:00:01 | 12007| transaksieid| DeelSlot| 2019-09-17 10:05:03.327933| 389015618226997618| {11629}| 00:00:13 | 12007| transaksieid| DeelSlot| 2019-09-17 10:05:03.327933| 389015618226997618| {11092}| 00:01:10 | 12007| transaksieid| DeelSlot| 2019-09-17 10:05:03.327933| 389015618226997618| {11288}| 00:00:05 | 12213| transaksieid| DeelSlot| 2019-09-17 10:06:07.328019| 389015618226997618| {12007}| 00:00:10

NEEM SLOTE DEUR SLOTTIPE DEUR QUERYID

Navraag

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

Voorbeeld

| NEEM SLOTE DEUR SLOTTIPE DEUR QUERYID +-----------------------------------+ ----------------------------+--------------------+ --------------------+---------------------------- | pid| slottipe| modus| begin| navraag| blocking_pids| duur +----------+--------------------------------+---------------- ----------+-------------------------------------+--------- ----------------------------------+ --- | 11288| verhouding| RowExclusiveLock| 2019-09-17 10:00:00.302936| 389015618226997618| {11092}| 00:03:34 | 11092| transaksieid| EksklusieweSlot| 2019-09-17 10:00:00.302936| 389015618226997618| {}| 00:03:34 | 11288| verhouding| RowExclusiveLock| 2019-09-17 10:00:00.302936| 389015618226997618| {}| 00:00:10 | 11092| verhouding| RowExclusiveLock| 2019-09-17 10:00:00.302936| 389015618226997618| {}| 00:03:34 | 11092| virtualxid| EksklusieweSlot| 2019-09-17 10:00:00.302936| 389015618226997618| {}| 00:03:34 | 11288| virtualxid| EksklusieweSlot| 2019-09-17 10:00:00.302936| 389015618226997618| {11092}| 00:03:34 | 11288| transaksieid| EksklusieweSlot| 2019-09-17 10:00:00.302936| 389015618226997618| {11092}| 00:03:34 | 11288| tupel| AccessExclusive Lock| 2019-09-17 10:00:00.302936| 389015618226997618| {11092}| 00:03:34

Gebruik slotgeskiedenis om prestasie-insidente te ontleed.

'n Versoek met queryid=389015618226997618 uitgevoer deur 'n proses met pid=11288 het vir 2019 minute gewag vir blokkering vanaf 09-17-10 00:00:3.
Die slot is gehou deur 'n proses met pid=11092
'n Proses met pid=11092 wat 'n versoek uitvoer met queryid=389015618226997618 vanaf 2019-09-17 10:00:00 het die slot vir 3 minute gehou.

Totale

Nou, hoop ek, sal die interessantste en nuttigste deel begin - die versameling van statistieke en die ontleding van gevalle oor die geskiedenis van wagte en blokkasies.

In die toekoms, wil ek glo, sal ons 'n stel van 'n paar notas kry (soortgelyk aan Oracle se metalink).

Oor die algemeen is dit om hierdie rede dat die metodologie wat gebruik word so vinnig as moontlik aan almal beskikbaar gestel word.

Ek sal probeer om die projek in die nabye toekoms op github te plaas.

Bron: will.com

Een van die metodes om slotgeskiedenis in PostgreSQL te kry

Voer data in

Geskiedenis van pg_locks voorstelling

Uitset

WAG VIR SLUITE DEUR SLOTTIPE

OPNAME VAN SLUITE PER SLOTTIPE

WAG VIR SLUITE DEUR SLOTTIPE DEUR QUERYID

NEEM SLOTE DEUR SLOTTIPE DEUR QUERYID

Totale

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