Artikli jätk "
Artiklis vaadeldakse ja näidatakse konkreetsete päringute ja näidete puhul, millist kasulikku teavet saate pg_locksi vaateajaloo abil.
Hoiatus.
Teema uudsuse ja testimisperioodi ebatäielikkuse tõttu võib artikkel sisaldada vigu. Kriitika ja kommentaarid on teretulnud ja oodatud.
Sisendandmed
pg_locksi esituse ajalugu
arhiivi_lukustamine
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
);
Põhimõtteliselt on tabel lauaga sarnane archive_pg_stat_activitytäpsemalt kirjeldatud siin -
Veeru täitmiseks queryid funktsiooni kasutatakse
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;
Selgitus: queryid veeru väärtust värskendatakse tabelis history_locking ja seejärel kui tabeli archive_locking jaoks luuakse uus partitsioon, salvestatakse väärtus ajaloolistesse väärtustesse.
Выходные данные
Üldine teave protsesside kohta üldiselt.
LUKKE OOTAMINE LUKKU TÜÜPIDE JÄRGI
Päring
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
Näide
| OOTA LUKKID LUKKU TÜÜPIDE JÄRGI +---------------------+------------------------ -------+--------------------- | lukutüüp| režiim| kestus +--------------------+--------------------- ---+-- ------------------- | tehinguid| sharelock| 19:39:26 | mitmekordne| AccessExclusiveLock| 00:03:35 +----------------------------------------------- -------+---------------------
LUKKUDE VÕTMINE LUKKU TÜÜPIDE JÄRGI
Päring
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
Näide
| LUKKUDE VÕTMINE LUKKU TÜÜPIDE JÄRGI +---------------------+----------------------- -------+--------------------- | lukutüüp| režiim| kestus +--------------------+--------------------- ---+-- ------------------- | seos| RowExclusiveLock| 51:11:10 | virtualxid| ExclusiveLock| 48:10:43 | tehinguid| ExclusiveLock| 44:24:53 | seos| AccessShareLock| 20:06:13 | mitmekordne| AccessExclusiveLock| 17:58:47 | mitmekordne| ExclusiveLock| 01:40:41 | seos| ShareUpdateExclusiveLock| 00:26:41 | objekt| RowExclusiveLock| 00:00:01 | tehinguid| sharelock| 00:00:01 | pikendada| ExclusiveLock| 00:00:01 +--------------------+------------------------ -------+---------------------
Üksikasjalik teave konkreetsete päringu ID-päringute jaoks
LUKKE OOTAMINE LUKKU TÜÜPIDE JÄRGI PÄRINGUID
Päring
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
Näide
| LUKKE OOTAMINE LUKKU TÜÜPIDE JÄRGI PÄRINGUID JÄRGI +----------+-------------------------+------ ---------------+-------------------------------+---- ------------------------------------------+----------- - --------- | pid| lukutüüp| režiim| algas| queryid| blocking_pids| kestus +----------+--------------------------+------------ ---------+-------------------------------+---------- ---+--------------------+------------------ --- | 11288| tehinguid| sharelock| 2019 09:17:10| 00| {00.302936}| 389015618226997618:11092:00 | 03| tehinguid| sharelock| 34-11626-2019 09:17:10| 00| {21.380921}| 389015618226997618:12380:00 | 00| tehinguid| sharelock| 29-11626-2019 09:17:10| 00| {21.380921}| 389015618226997618:11092:00 | 03| tehinguid| sharelock| 25-11626-2019 09:17:10| 00| {21.380921}| 389015618226997618:12213:00 | 01| tehinguid| sharelock| 55-11626-2019 09:17:10| 00| {21.380921}| 389015618226997618:12751:00 | 00| tehinguid| sharelock| 01 11629:2019:09| 17| {10}| 00:24.331935:389015618226997618 | 11092| tehinguid| sharelock| 00 03:22:11629| 2019| {09}| 17:10:00 | 24.331935| tehinguid| sharelock| 389015618226997618 12007:00:00| 01| {12007}| 2019:09:17 | 10| tehinguid| sharelock| 05 03.327933:389015618226997618:11629| 00| {00}| 13:12007:2019 | 09| tehinguid| sharelock| 17 10:05:03.327933| 389015618226997618| {11092}| 00:01:10 | 12007| tehinguid| sharelock| 2019-09-17 10:05:03.327933| 389015618226997618| {11288}| 00:00:05
LUKKUDE VÕTMINE LOCKTYPES PÄRINGUID JÄRGI
Päring
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
Näide
| LUKKUDE VÕTMINE LUKKU TÜÜPIDE JÄRGI PÄRINGUID JÄRGI +-----------+-------------------------+------- --------------+------------------------------+----- -+--------------------+------------ --------- | pid| lukutüüp| režiim| algas| queryid| blocking_pids| kestus +----------+--------------------------+------------ ---------+-------------------------------+---------- ---+--------------------+------------------ --- | 11288| seos| RowExclusiveLock| 2019 09:17:10| 00| {00.302936}| 389015618226997618:11092:00 | 03| tehinguid| ExclusiveLock| 34 11092:2019:09| 17| {}| 10:00:00.302936 | 389015618226997618| seos| RowExclusiveLock| 00 03:34:11288| 2019| {}| 09:17:10 | 00| seos| RowExclusiveLock| 00.302936 389015618226997618:00:00| 10| {}| 11092:2019:09 | 17| virtualxid| ExclusiveLock| 10 00:00.302936:389015618226997618| 00| {}| 03:34:11092 | 2019| virtualxid| ExclusiveLock| 09 17:10:00| 00.302936| {389015618226997618}| 00:03:34 | 11288| tehinguid| ExclusiveLock| 2019 09:17:10| 00| {00.302936}| 389015618226997618:11092:00 | 03| mitmekordne| AccessExclusiveLock| 34 11288:2019:09| 17| {10}| 00:00.302936:389015618226997618
Blokeerimisajaloo kasutamine toimivusjuhtumite analüüsimisel.
- Päring queryid=389015618226997618, mille käivitas protsess pid=11288, on oodanud lukustamist alates 2019-09-17 10:00:00 3 minutit.
- Lukku hoidis protsess, mille pid=11092
- Protsess pid=11092, mis käivitas päringu queryid=389015618226997618 alates 2019-09-17 10:00:00, hoidis lukku 3 minutit.
Summaarne
Loodan, et nüüd algab kõige huvitavam ja kasulikum – statistika kogumine ning ootuste ja blokeerimise ajaloo juhtumite analüüsimine.
Tulevikus tahaks uskuda, et saate mingisuguse sedeli komplekti (sarnaselt Oracle'i metallinkile).
Üldiselt just sel põhjusel kuvatakse kasutatav metoodika võimalikult kiiresti avalikkusele tutvumiseks.
Üritan lähiajal projekti githubisse panna.
Allikas: www.habr.com