ืคึผืจืึธื”ืึธืกื˜ืขืจ > ื‘ืœืึธื’ > ืึทื“ืžื™ื ื™ืกื˜ืจืึทืฆื™ืข > ืื™ื™ื ืขืจ ืคื•ืŸ ื“ื™ ืžืขื˜ื”ืึธื“ืก ืฆื• ื‘ืึทืงื•ืžืขืŸ ืฉืœืึธืก ื’ืขืฉื™ื›ื˜ืข ืื™ืŸ PostgreSQL

ืื™ื™ื ืขืจ ืคื•ืŸ ื“ื™ ืžืขื˜ื”ืึธื“ืก ืฆื• ื‘ืึทืงื•ืžืขืŸ ืฉืœืึธืก ื’ืขืฉื™ื›ื˜ืข ืื™ืŸ PostgreSQL

ื”ืžืฉืš ืคื•ืŸ ื“ืขื ืึทืจื˜ื™ืงืœ "ืึทืŸ ืคึผืจื•ื•ื•ืŸ ืฆื• ืฉืึทืคึฟืŸ ืึทืŸ ืึทื ืึทืœืึธื’ ืคื•ืŸ ASH ืคึฟืึทืจ PostgreSQL ".

ื“ืขืจ ืึทืจื˜ื™ืงืœ ื•ื•ืขื˜ ื‘ืึทื˜ืจืึทื›ื˜ืŸ ืื•ืŸ ื•ื•ื™ื™ึทื–ืŸ ืื•ื™ืฃ ืกืคึผืขืฆื™ืคื™ืฉ ืคึฟืจืื’ืŸ ืื•ืŸ ื‘ื™ื™ืฉืคื™ืœืŸ ื•ื•ืึธืก ื ื•ืฆื™ืง ืื™ื ืคึฟืึธืจืžืึทืฆื™ืข ืงืขื ืขืŸ ื–ื™ื™ืŸ ื‘ืืงื•ืžืขืŸ ืžื™ื˜ ื“ื™ pg_locks View ื’ืขืฉื™ื›ื˜ืข.

Warning
ืจืขื›ื˜ ืฆื• ื“ืขืจ ื ื™ื™ึทืงื™ื™ึทื˜ ืคื•ืŸ ื“ื™ ื˜ืขืžืข ืื•ืŸ ื“ื™ ื™ื ืงืึธืžืคึผืœืขื˜ืขื ืขืกืก ืคื•ืŸ ื“ื™ ื˜ืขืกื˜ื™ื ื’ ืฆื™ื™ึทื˜, ื“ืขืจ ืึทืจื˜ื™ืงืœ ืงืขืŸ ืึทื ื˜ื”ืึทืœื˜ืŸ ืขืจืจืึธืจืก. ืงืจื™ื˜ื™ืง ืื•ืŸ ื‘ืึทืžืขืจืงื•ื ื’ืขืŸ ื–ืขื ืขืŸ ื‘ืึทื’ืจื™ืกื•ื ื’ ืื•ืŸ ื“ืขืจื•ื•ืึทืจื˜.

ืึทืจื™ื™ึทื ืฉืจื™ื™ึทื‘ ื“ืึทื˜ืŸ

pg_locks ืคืึทืจื˜ืจืขื˜ื•ื ื’ ื’ืขืฉื™ื›ื˜ืข

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 
);

ื‘ื™ื™ืกื™ืงืœื™, ื“ื™ ื˜ื™ืฉ ืื™ื– ืขื ืœืขืš ืฆื• ื“ื™ ื˜ื™ืฉ archive_pg_stat_activityื“ื™ืกืงืจื™ื™ื‘ื“ ืื™ืŸ ืžืขืจ ื“ืขื˜ืึทืœ ื“ืึธ - pg_stat_statements + pg_stat_activity + loq_query = pg_ash? ืื•ืŸ ื“ื - ืึทืŸ ืคึผืจื•ื•ื•ืŸ ืฆื• ืฉืึทืคึฟืŸ ืึทืŸ ืึทื ืึทืœืึธื’ ืคื•ืŸ ASH ืคึฟืึทืจ PostgreSQL.

ืฆื• ืคึผืœืึธืžื‘ื™ืจืŸ ืึท ื–ื™ื™ึทืœ queryid ืคึฟื•ื ืงืฆื™ืข ืื™ื– ื’ืขื ื•ืฆื˜

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;

ื“ืขืจืงืœืขืจื•ื ื’: ื“ื™ ื•ื•ืขืจื˜ ืคื•ืŸ ื“ื™ queryid ื–ื™ื™ึทืœ ืื™ื– ื“ืขืจื”ื™ื™ึทื ื˜ื™ืงื˜ ืื™ืŸ ื“ื™ History_locking ื˜ื™ืฉ, ืื•ืŸ ื•ื•ืขืŸ ืึท ื ื™ื™ึทืข ืฆืขื˜ื™ื™ืœื•ื ื’ ืื™ื– ื‘ืืฉืืคืŸ ืคึฟืึทืจ ื“ื™ archive_locking ื˜ื™ืฉ, ื“ื™ ื•ื•ืขืจื˜ ื•ื•ืขื˜ ื–ื™ื™ืŸ ืกื˜ืึธืจื“ ืื™ืŸ ื”ื™ืกื˜ืืจื™ืฉืข ื•ื•ืึทืœื•ืขืก.

ะ’ั‹ั…ะพะดะฝั‹ะต ะดะฐะฝะฝั‹ะต

ืึทืœื’ืขืžื™ื™ื ืข ืื™ื ืคึฟืึธืจืžืึทืฆื™ืข ื•ื•ืขื’ืŸ ืคึผืจืึทืกืขืกืึทื– ืื™ืŸ ืึทืœื’ืขืžื™ื™ืŸ.

ื•ื•ืืจื˜ืŸ ืคึฟืึทืจ ืœืึทืงืก ื“ื•ืจืš ืœืึธืงืงื˜ื™ืคึผืขืก

ื‘ืขื˜ืŸ

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

ื‘ื™ื™ึทืฉืคึผื™ืœ

| ื•ื•ืืจื˜ืŸ ืคึฟืึทืจ ืœืึทืงืก ื“ื•ืจืš ืœืึธืงืงื˜ื™ืคึผืขืก +------------------------ -------+--------------------------- | locktype| ืžืึธื“ืข| ื’ืขื“ื•ื™ืขืจ +--------------------+------------------ ------------------ | ื˜ืจืึทื ืกืึทืงื˜ื™ืึธืŸ | sharelock| 19:39:26 | tuple| AccessExclusiveLock| 00:03:35 +---------------------+------------------------ -------+--------------------

ื ืขืžืขืŸ ืคื•ืŸ ืœืึทืงืก ื“ื•ืจืš ืœืึธืงืงื˜ื™ืคึผืขืก

ื‘ืขื˜ืŸ

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

ื‘ื™ื™ึทืฉืคึผื™ืœ

| ื ืขืžืขืŸ ืคื•ืŸ ืœืึทืงืก ื“ื•ืจืš ืœืึธืงืงื˜ื™ืคึผืขืก +------------------------+---------------------------------------- -------+--------------------------- | locktype| ืžืึธื“ืข| ื’ืขื“ื•ื™ืขืจ +--------------------+------------------ ------------------ | ื‘ืึทืฆื™ื•ื ื’| RowExclusiveLock| 51:11:10 | virtualxid| ExclusiveLock| 48:10:43 | ื˜ืจืึทื ืกืึทืงื˜ื™ืึธืŸ | ExclusiveLock| 44:24:53 | ื‘ืึทืฆื™ื•ื ื’| AccessShareLock| 20:06:13 | tuple| AccessExclusiveLock| 17:58:47 | tuple| ExclusiveLock| 01:40:41 | ื‘ืึทืฆื™ื•ื ื’| ShareUpdateExclusiveLock| 00:26:41 | ื›ื™ื™ืคืขืฅ| RowExclusiveLock| 00:00:01 | ื˜ืจืึทื ืกืึทืงื˜ื™ืึธืŸ | sharelock| 00:00:01 | ืคืึทืจื‘ืจื™ื™ื˜ืขืจืŸ| ExclusiveLock| 00:00:01 +--------------------+------------------------ -------+--------------------

ื“ื™ื˜ื™ื™ืœื“ ืื™ื ืคึฟืึธืจืžืึทืฆื™ืข ืคึฟืึทืจ ืกืคึผืขืฆื™ืคื™ืฉ ืงื•ื•ืขืจื™ื™ื“ ืงื•ื•ื™ืจื™ื–

ื•ื•ืืจื˜ืŸ ืคึฟืึทืจ ืœืึทืงืก ื“ื•ืจืš ืœืึธืงืงื˜ื™ืคึผืขืก ื“ื•ืจืš QUERYID

ื‘ืขื˜ืŸ

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

ื‘ื™ื™ึทืฉืคึผื™ืœ

| ื•ื•ืืจื˜ืŸ ืคึฟืึทืจ ืœืึทืงืก ื“ื•ืจืš ืœืึธืงืงื˜ื™ืคึผืขืก ื“ื•ืจืš QUERYID +-----+------------------------+----- ---------------+-------------------------------+--- ------------------+--------------------+---------- - ---------- | ืคึผื™ื“| locktype| ืžืึธื“ืข| ืกื˜ืึทืจื˜ืขื“| queryid| blocking_pids| ื’ืขื“ื•ื™ืขืจ +------------------------ ----------+-------------------------------------+--------- ---+--------------------+---------------- --- | 11288| ื˜ืจืึทื ืกืึทืงื˜ื™ืึธืŸ | sharelock| 2019-09-17 10:00:00.302936| 389015618226997618| {11092}| 00:03:34 | 11626| ื˜ืจืึทื ืกืึทืงื˜ื™ืึธืŸ | sharelock| 2019-09-17 10:00:21.380921| 389015618226997618| {12380}| 00:00:29 | 11626| ื˜ืจืึทื ืกืึทืงื˜ื™ืึธืŸ | sharelock| 2019-09-17 10:00:21.380921| 389015618226997618| {11092}| 00:03:25 | 11626| ื˜ืจืึทื ืกืึทืงื˜ื™ืึธืŸ | sharelock| 2019-09-17 10:00:21.380921| 389015618226997618| {12213}| 00:01:55 | 11626| ื˜ืจืึทื ืกืึทืงื˜ื™ืึธืŸ | sharelock| 2019-09-17 10:00:21.380921| 389015618226997618| {12751}| 00:00:01 | 11629| ื˜ืจืึทื ืกืึทืงื˜ื™ืึธืŸ | sharelock| 2019-09-17 10:00:24.331935| 389015618226997618| {11092}| 00:03:22 | 11629| ื˜ืจืึทื ืกืึทืงื˜ื™ืึธืŸ | sharelock| 2019-09-17 10:00:24.331935| 389015618226997618| {12007}| 00:00:01 | 12007| ื˜ืจืึทื ืกืึทืงื˜ื™ืึธืŸ | sharelock| 2019-09-17 10:05:03.327933| 389015618226997618| {11629}| 00:00:13 | 12007| ื˜ืจืึทื ืกืึทืงื˜ื™ืึธืŸ | sharelock| 2019-09-17 10:05:03.327933| 389015618226997618| {11092}| 00:01:10 | 12007| ื˜ืจืึทื ืกืึทืงื˜ื™ืึธืŸ | sharelock| 2019-09-17 10:05:03.327933| 389015618226997618| {11288}| 00:00:05 | 12213| ื˜ืจืึทื ืกืึทืงื˜ื™ืึธืŸ | sharelock| 2019-09-17 10:06:07.328019| 389015618226997618| {12007}| 00:00:10

ื ืขืžืขืŸ ืœืึทืงืก ื“ื•ืจืš ืœืึธืงืงื˜ื™ืคึผืขืก ื“ื•ืจืš QUERYID

ื‘ืขื˜ืŸ

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

ื‘ื™ื™ึทืฉืคึผื™ืœ

| ื ืขืžืขืŸ ืœืึทืงืก ื“ื•ืจืš ืœืึธืงืงื˜ื™ืคึผืขืก ื“ื•ืจืš QUERYID +-----+------------------------+------ --------------+--------------------------------+ -+--------------------+------------------------ | ืคึผื™ื“| locktype| ืžืึธื“ืข| ืกื˜ืึทืจื˜ืขื“| queryid| blocking_pids| ื’ืขื“ื•ื™ืขืจ +------------------------ ----------+-------------------------------------+--------- ---+--------------------+---------------- --- | 11288| ื‘ืึทืฆื™ื•ื ื’| RowExclusiveLock| 2019-09-17 10:00:00.302936| 389015618226997618| {11092}| 00:03:34 | 11092| ื˜ืจืึทื ืกืึทืงื˜ื™ืึธืŸ | ExclusiveLock| 2019-09-17 10:00:00.302936| 389015618226997618| {}| 00:03:34 | 11288| ื‘ืึทืฆื™ื•ื ื’| RowExclusiveLock| 2019-09-17 10:00:00.302936| 389015618226997618| {}| 00:00:10 | 11092| ื‘ืึทืฆื™ื•ื ื’| 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| ื˜ืจืึทื ืกืึทืงื˜ื™ืึธืŸ | ExclusiveLock| 2019-09-17 10:00:00.302936| 389015618226997618| {11092}| 00:03:34 | 11288| tuple| AccessExclusiveLock| 2019-09-17 10:00:00.302936| 389015618226997618| {11092}| 00:03:34

ื ื™ืฆืŸ ื‘ืœืึทืงื™ื ื’ ื’ืขืฉื™ื›ื˜ืข ื•ื•ืขืŸ ืึทื ืึทืœื™ื™ื–ื™ื ื’ ืคืึธืจืฉื˜ืขืœื•ื ื’ ื™ื ืกืึทื“ืึทื ืฅ.

  1. ื ืึธื ืคึฟืจืขื’ ืžื™ื˜ queryid=389015618226997618 ืขืงืกืึทืงื™ื•ื˜ืึทื“ ื“ื•ืจืš ืึท ืคึผืจืึธืฆืขืก ืžื™ื˜ pid=11288 ื”ืื˜ ืฉื•ื™ืŸ ื•ื•ืืจื˜ืŸ ืคึฟืึทืจ ืึท ืฉืœืึธืก ื–ื™ื ื˜ 2019-09-17 10:00:00 ืคึฟืึทืจ 3 ืžื™ื ื•ื˜.
  2. ื“ื™ ืฉืœืึธืก ืื™ื– ื’ืขื”ืืœื˜ืŸ ื“ื•ืจืš ืึท ืคึผืจืึธืฆืขืก ืžื™ื˜ ืคึผื™ื“=11092
  3. ื ืคึผืจืึธืฆืขืก ืžื™ื˜ pid=11092 ืขืงืกืึทืงื™ื•ื˜ื™ื ื’ ืึท ืึธื ืคึฟืจืขื’ ืžื™ื˜ queryid=389015618226997618 ื–ื™ื ื˜ 2019-09-17 10:00:00 ื’ืขื”ืืœื˜ืŸ ื“ื™ ืฉืœืึธืก ืคึฟืึทืจ 3 ืžื™ื ื•ื˜.

ื’ืึทื ืฅ

ืื™ืฆื˜, ืื™ืš ื”ืึธืคึฟืŸ, ื“ื™ ืžืขืจืกื˜ ื˜ืฉื™ืงืึทื•ื•ืข ืื•ืŸ ื ื•ืฆื™ืง ื–ืึทืš ื•ื•ืขื˜ ืึธื ื”ื™ื™ื‘ืŸ - ืงืึทืœืขืงื˜ื™ื ื’ ืกื˜ืึทื˜ื™ืกื˜ื™ืง ืื•ืŸ ืึทื ืึทืœื™ื™ื–ื™ื ื’ ืงืึทืกืขืก ืื•ื™ืฃ ื“ืขืจ ื’ืขืฉื™ื›ื˜ืข ืคื•ืŸ โ€‹โ€‹ืขืงืกืคึผืขืงื˜ื™ื™ืฉืึทื ื– ืื•ืŸ ื‘ืœืึทืงื™ื ื’.

ืื™ืŸ ื“ืขืจ ืฆื•ืงื•ื ืคึฟื˜, ืื™ืš ื•ื•ืึธืœื˜ ื•ื•ื™ ืฆื• ื’ืœื•ื™ื‘ืŸ, ืื™ืจ ื•ื•ืขื˜ ื‘ืึทืงื•ืžืขืŸ ืึท ืกื›ื•ื ืคื•ืŸ ืึท ืžื™ืŸ ืคื•ืŸ ื˜ืึธืŸ (ืขื ืœืขืš ืฆื• ืึธืจืึทืงืœืข ืก ืžืขื˜ืึทืœืœื™ื ืง).

ืื™ืŸ ืึทืœื’ืขืžื™ื™ืŸ, ืขืก ืื™ื– ืคึฟืึทืจ ื“ืขื ืกื™ื‘ื” ืึทื– ื“ื™ ืžืขื˜ืึทื“ืึทืœืึทื“ื–ืฉื™ ื’ืขื ื™ืฆื˜ ืื™ื– ื’ืขื•ื•ื™ื–ืŸ ื•ื•ื™ ื’ืขืฉื•ื•ื™ื ื“ ื•ื•ื™ ืžืขื’ืœืขืš ืคึฟืึทืจ ืฆื™ื‘ื•ืจ ืคืึทืžื™ืœื™ืึทืจื™ื–ืึทื˜ื™ืึธืŸ.

ืื™ืŸ ื“ืขืจ ื ืึธืขื ื˜ ืฆื•ืงื•ื ืคื˜ ืื™ืš ื•ื•ืขืœ ืคึผืจื•ื‘ื™ืจืŸ ืฆื• ืฉื˜ืขืœืŸ ื“ื™ ืคึผืจื•ื™ืขืงื˜ ืื•ื™ืฃ ื’ื™ื˜ื”ื•ื‘.

ืžืงื•ืจ: www.habr.com

ืœื™ื™ื’ืŸ ืึท ื‘ืึทืžืขืจืงื•ื ื’