🥇 Unu di i metudi per ottene a storia di serratura in PostgreSQL

Continuazione di l'articulu "Un tentativu di creà un analogu ASH per PostgreSQL ".

L'articulu esaminà è mostrarà, utilizendu dumande è esempii specifichi, quale infurmazione utile pò esse ottenuta usendu a storia di a vista pg_locks.

Avvisu.
A causa di a novità di u tema è u periodu di teste infinitu, l'articulu pò cuntene errori. I critichi è i cumenti sò assai accolti è previsti.

Dati di input

Storia di a rapprisintazioni pg_locks

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 
);

Essenzialmente, a tavula hè simile à a tavola archive_pg_stat_activity, descritta in più dettagliu quì - pg_stat_statements + pg_stat_activity + loq_query = pg_ash? è quì - Un tentativu di creà un analogu di ASH per PostgreSQL.

Per riempie una colonna queryid a funzione hè aduprata

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;

Spiegazione: u valore di a colonna di queryid hè aghjurnatu in a table history_locking, è dopu quandu una nova partizione hè creata per a table archive_locking, u valore serà guardatu in i valori storichi.

Risultatu

Informazione generale nantu à i prucessi in generale.

ASPETTANDO LOCKS PER LOCKTYPES

Inchiesta

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

Esempiu:

| ASPETTANDO SERRATURE PER TIPI DI SERRATURA +-----------+----------------------- --------+ ------------------- | locktype| modu| durata +--------------------+--------------------------- --+-------------------- | transazzione| ShareLock| 19:39:26 | tupla| AccessExclusiveLock| 00:03:35 +-------------------+------------------------ -------+----------

TAKING OF LOCKS PER LOCKTYPES

Inchiesta

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

Esempiu:

| PRESE DI SERRATURA PER TIPI DI SERRATURA +--------------------+------------------------ --------+------------------- | locktype| modu| durata +--------------------+--------------------------- --+-------------------- | relazione| RowExclusiveLock| 51:11:10 | virtualxid| ExclusiveLock| 48:10:43 | transazzione | ExclusiveLock| 44:24:53 | relazione| AccessShareLock| 20:06:13 | tupla| AccessExclusiveLock| 17:58:47 | tupla| ExclusiveLock| 01:40:41 | relazione| ShareUpdateExclusiveLock| 00:26:41 | oggettu| RowExclusiveLock| 00:00:01 | transazzione | ShareLock| 00:00:01 | allargà| ExclusiveLock| 00:00:01 +-------------------+------------------------ -------+----------

Informazioni dettagliate nantu à e richieste specifiche di queryid

ASPETTANDO LOCKS PER LOCKTYPES PER QUERYID

Inchiesta

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

Esempiu:

| ASPETTANDO SERRATURE PER LOCKTYPES PER QUERYID +----------+----------+----- ---------------- +----------------------------+--- ------------------ -+--------------------+----------- ---------- | pid| locktype| modu| principiatu| queryid| blocking_pids| durata +----------+-------------------------+------------ ---------+-----------------------------+---------- -----------+--------------------+------------------ --- | 11288| transazzione| ShareLock| 2019-09-17 10:00:00.302936| 389015618226997618| {11092}| 00:03:34 | 11626| transazzione| ShareLock| 2019-09-17 10:00:21.380921| 389015618226997618| {12380}| 00:00:29 | 11626| transazzione| ShareLock| 2019-09-17 10:00:21.380921| 389015618226997618| {11092}| 00:03:25 | 11626| transazzione| ShareLock| 2019-09-17 10:00:21.380921| 389015618226997618| {12213}| 00:01:55 | 11626| transazzione| ShareLock| 2019-09-17 10:00:21.380921| 389015618226997618| {12751}| 00:00:01 | 11629| transazzione| ShareLock| 2019-09-17 10:00:24.331935| 389015618226997618| {11092}| 00:03:22 | 11629| transazzione| ShareLock| 2019-09-17 10:00:24.331935| 389015618226997618| {12007}| 00:00:01 | 12007| transazzione| ShareLock| 2019-09-17 10:05:03.327933| 389015618226997618| {11629}| 00:00:13 | 12007| transazzione| ShareLock| 2019-09-17 10:05:03.327933| 389015618226997618| {11092}| 00:01:10 | 12007| transazzione| ShareLock| 2019-09-17 10:05:03.327933| 389015618226997618| {11288}| 00:00:05 | 12213| transazzione| ShareLock| 2019-09-17 10:06:07.328019| 389015618226997618| {12007}| 00:00:10

Pigliate i serrature per i tipi di serratura per queryID

Inchiesta

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

Esempiu:

| PITTURA DI SERRATURE PER LOCKTYPES PER QUERYID +----------+----------+------ ---------------+ ----------------------------+---- ----------------+ --------------------+------------ -------- | pid| locktype| modu| principiatu| queryid| blocking_pids| durata +----------+-------------------------+------------ ---------+-----------------------------+---------- -----------+--------------------+------------------ --- | 11288| relazione| RowExclusiveLock| 2019-09-17 10:00:00.302936| 389015618226997618| {11092}| 00:03:34 | 11092| transazzione| ExclusiveLock| 2019-09-17 10:00:00.302936| 389015618226997618| {}| 00:03:34 | 11288| relazione| RowExclusiveLock| 2019-09-17 10:00:00.302936| 389015618226997618| {}| 00:00:10 | 11092| relazione| RowExclusiveLock| 2019-09-17 10:00:00.302936| 389015618226997618| {}| 00:03:34 | 11092| virtualxid| ExclusiveLock| 2019-09-17 10:00:00.302936| 389015618226997618| {}| 00:03:34 | 11288| virtualxid| ExclusiveLock| 2019-09-17 10:00:00.302936| 389015618226997618| {11092}| 00:03:34 | 11288| transazzione| ExclusiveLock| 2019-09-17 10:00:00.302936| 389015618226997618| {11092}| 00:03:34 | 11288| tupla| AccessExclusiveLock| 2019-09-17 10:00:00.302936| 389015618226997618| {11092}| 00:03:34

Utilizà a storia di serratura per analizà incidenti di rendiment.

Una dumanda cù queryid = 389015618226997618 eseguita da un prucessu cù pid = 11288 era aspittendu per u bloccu à partesi da 2019-09-17 10:00:00 per 3 minuti.
A serratura hè stata tenuta da un prucessu cù pid = 11092
Un prucessu cù pid = 11092 eseguisce una dumanda cù queryid = 389015618226997618 à partesi da 2019-09-17 10:00:00 hà tenutu a serratura per 3 minuti.

U risultatu

Avà, speru, a parte più interessante è utile principiarà - cullà statistiche è analizà i casi nantu à a storia di l'attese è i blocchi.

In u futuru, vogliu crede, averemu un set di qualchi note (simile à u metalink d'Oracle).

In generale, hè per questu mutivu chì a metodulugia aduprata hè messa à a disposizione di tutti u più prestu pussibule.

Pruvaraghju di publicà u prughjettu nantu à github in un futuru vicinu.

Source: www.habr.com

Unu di i metudi per ottene a storia di serratura in PostgreSQL

Dati di input

Storia di a rapprisintazioni pg_locks

Risultatu

ASPETTANDO LOCKS PER LOCKTYPES

TAKING OF LOCKS PER LOCKTYPES

ASPETTANDO LOCKS PER LOCKTYPES PER QUERYID

Pigliate i serrature per i tipi di serratura per queryID

U risultatu

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