🥇Salah satu metode untuk mendapatkan riwayat kunci di PostgreSQL

Kelanjutan artikel "Upaya untuk membuat analog ASH untuk PostgreSQL ".

Artikel ini akan memeriksa dan menunjukkan, menggunakan kueri dan contoh spesifik, informasi berguna apa yang dapat diperoleh dengan menggunakan riwayat tampilan pg_locks.

Peringatan
Karena topik yang baru dan masa pengujian yang belum selesai, artikel mungkin mengandung kesalahan. Kritik dan komentar sangat kami harapkan dan harapkan.

Memasukan data

Sejarah representasi pg_locks

pengunci_arsip

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 
);

Intinya, tabel itu mirip dengan tabel archive_pg_stat_activity, dijelaskan lebih detail di sini - pg_stat_statements + pg_stat_activity + loq_query = pg_ash? dan di sini - Upaya untuk membuat analog ASH untuk PostgreSQL.

Untuk mengisi kolom id kueri fungsi digunakan

perbarui_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;

Penjelasan: nilai kolom queryid diperbarui di tabel history_locking, dan kemudian ketika partisi baru dibuat untuk tabel archive_locking, nilainya akan disimpan dalam nilai historis.

Keluaran

Informasi umum tentang proses secara umum.

MENUNGGU KUNCI BERDASARKAN JENIS KUNCI

Minta

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

Contoh

| MENUNGGU KUNCI BERDASARKAN JENIS KUNCI +-----------+----------------------- --------+ ------------------- | tipe kunci| modus| durasi +-----+-------------------------- - --+----- | transaksiid| BagikanKunci| 19:39:26 | tupel| AksesKunci Eksklusif| 00:03:35 +----+----------------------- - -------+----------

PENGAMBILAN KUNCI BERDASARKAN JENIS KUNCI

Minta

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

Contoh

| PENGAMBILAN KUNCI BERDASARKAN JENIS KUNCI +-----+--------------------------------------- -----------------------+------------------- | tipe kunci| modus| durasi +-----+-------------------------- - --+----- | hubungan| BarisKunci Eksklusif| 51:11:10 | virtualxid| Kunci Eksklusif| 48:10:43 | transaksiid| Kunci Eksklusif| 44:24:53 | hubungan| AksesShareLock| 20:06:13 | tupel| AksesKunci Eksklusif| 17:58:47 | tupel| Kunci Eksklusif| 01:40:41 | hubungan| BagikanPembaruanKunci Eksklusif| 00:26:41 | objek| BarisKunci Eksklusif| 00:00:01 | transaksiid| BagikanKunci| 00:00:01 | memperpanjang| Kunci Eksklusif| 00:00:01 +----+----------------------- - -------+----------

Informasi terperinci tentang permintaan queryid tertentu

MENUNGGU KUNCI BERDASARKAN JENIS KUNCI BERDASARKAN QUERYID

Minta

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

Contoh

| MENUNGGU KUNCI BERDASARKAN JENIS KUNCI BERDASARKAN QUERYID +----------+----------+----- --------------- +-------------+--- ----------------- -+-----+----------- --------- | pid| tipe kunci| modus| dimulai| ID kueri| memblokir_pids| durasi +----------+-------------------------+----------- ---------+----------------+--------- --------------------------+------+----------------- --- | 11288| transaksiid| BagikanKunci| 2019-09-17 10:00:00.302936| 389015618226997618| {11092}| 00:03:34 | 11626| transaksiid| BagikanKunci| 2019-09-17 10:00:21.380921| 389015618226997618| {12380}| 00:00:29 | 11626| transaksiid| BagikanKunci| 2019-09-17 10:00:21.380921| 389015618226997618| {11092}| 00:03:25 | 11626| transaksiid| BagikanKunci| 2019-09-17 10:00:21.380921| 389015618226997618| {12213}| 00:01:55 | 11626| transaksiid| BagikanKunci| 2019-09-17 10:00:21.380921| 389015618226997618| {12751}| 00:00:01 | 11629| transaksiid| BagikanKunci| 2019-09-17 10:00:24.331935| 389015618226997618| {11092}| 00:03:22 | 11629| transaksiid| BagikanKunci| 2019-09-17 10:00:24.331935| 389015618226997618| {12007}| 00:00:01 | 12007| transaksiid| BagikanKunci| 2019-09-17 10:05:03.327933| 389015618226997618| {11629}| 00:00:13 | 12007| transaksiid| BagikanKunci| 2019-09-17 10:05:03.327933| 389015618226997618| {11092}| 00:01:10 | 12007| transaksiid| BagikanKunci| 2019-09-17 10:05:03.327933| 389015618226997618| {11288}| 00:00:05 | 12213| transaksiid| BagikanKunci| 2019-09-17 10:06:07.328019| 389015618226997618| {12007}| 00:00:10

MENGAMBIL KUNCI BERDASARKAN JENIS KUNCI BERDASARKAN QUERYID

Minta

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

Contoh

| MENGAMBIL KUNCI BERDASARKAN JENIS KUNCI BERDASARKAN QUERYID +----------+----------+------ --------------+ ----------------------------+---- -+ --------------------+------------ -------- | pid| tipe kunci| modus| dimulai| ID kueri| memblokir_pids| durasi +----------+-------------------------+----------- ---------+---------------+--------- --------------------------+------+----------------- --- | 11288| hubungan| BarisKunci Eksklusif| 2019-09-17 10:00:00.302936| 389015618226997618| {11092}| 00:03:34 | 11092| transaksiid| Kunci Eksklusif| 2019-09-17 10:00:00.302936| 389015618226997618| {}| 00:03:34 | 11288| hubungan| BarisKunci Eksklusif| 2019-09-17 10:00:00.302936| 389015618226997618| {}| 00:00:10 | 11092| hubungan| BarisKunci Eksklusif| 2019-09-17 10:00:00.302936| 389015618226997618| {}| 00:03:34 | 11092| virtualxid| Kunci Eksklusif| 2019-09-17 10:00:00.302936| 389015618226997618| {}| 00:03:34 | 11288| virtualxid| Kunci Eksklusif| 2019-09-17 10:00:00.302936| 389015618226997618| {11092}| 00:03:34 | 11288| transaksiid| Kunci Eksklusif| 2019-09-17 10:00:00.302936| 389015618226997618| {11092}| 00:03:34 | 11288| tupel| AksesKunci Eksklusif| 2019-09-17 10:00:00.302936| 389015618226997618| {11092}| 00:03:34

Menggunakan riwayat kunci untuk menganalisis insiden kinerja.

Permintaan dengan queryid=389015618226997618 dieksekusi oleh proses dengan pid=11288 menunggu pemblokiran mulai dari 2019-09-17 10:00:00 selama 3 menit.
Kunci ditahan oleh proses dengan pid=11092
Sebuah proses dengan pid=11092 mengeksekusi permintaan dengan queryid=389015618226997618 mulai dari 2019-09-17 10:00:00 menahan kunci selama 3 menit.

Total

Sekarang, saya harap, bagian yang paling menarik dan bermanfaat akan dimulai - mengumpulkan statistik dan menganalisis kasus-kasus tentang sejarah penantian dan pemblokiran.

Di masa depan, saya yakin, kita akan mendapatkan serangkaian catatan (mirip dengan metalink Oracle).

Secara umum, karena alasan inilah metodologi yang digunakan tersedia bagi semua orang secepat mungkin.

Saya akan mencoba memposting proyek ini di github dalam waktu dekat.

Sumber: www.habr.com

Salah satu metode untuk mendapatkan riwayat kunci di PostgreSQL

Memasukan data

Sejarah representasi pg_locks

Keluaran

MENUNGGU KUNCI BERDASARKAN JENIS KUNCI

PENGAMBILAN KUNCI BERDASARKAN JENIS KUNCI

MENUNGGU KUNCI BERDASARKAN JENIS KUNCI BERDASARKAN QUERYID

MENGAMBIL KUNCI BERDASARKAN JENIS KUNCI BERDASARKAN QUERYID

Total

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