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Ittella’ log PostgreSQL mill-sħaba tal-AWS

Jew tetrisology ftit applikat.
Kollox ġdid huwa minsi sew qodma.
Epigrafi.
Ittella’ log PostgreSQL mill-sħaba tal-AWS

Dikjarazzjoni tal-problema

Għandek bżonn perjodikament tniżżel il-fajl tal-log PostgreSQL attwali mill-sħaba tal-AWS għall-host Linux lokali tiegħek. Mhux fil-ħin reali, iżda, ejja ngħidu, b'dewmien żgħir.
Il-perjodu tat-tniżżil tal-aġġornament tal-log file huwa ta' 5 minuti.
Il-log file fl-AWS jiddawwar kull siegħa.

Għodda wżata

Biex tniżżel il-fajl log lill-host, jintuża script bash li jsejjaħ l-AWS API "aws rds download-db-log-file-portion".

Parametri:

  • —db-instance-identifier: isem tal-istanza AWS;
  • --log-file-name: isem il-log file iġġenerat bħalissa
  • --max-item: In-numru totali ta 'oġġetti rritornati fl-output tal-kmand.Id-daqs tal-porzjon tal-fajl imniżżel.
  • --starting-token: Token tal-bidu

F'dan il-każ partikolari, il-kompitu tat-tagħbija zkuk qamet waqt ix-xogħol fuq monitoraġġ tal-prestazzjoni tal-mistoqsijiet PostgreSQL.

U huwa sempliċi - kompitu interessanti għat-taħriġ u l-varjetà matul il-ħinijiet tax-xogħol.
Se nassumi li l-problema diġà ġiet solvuta minħabba l-ħajja ta 'kuljum. Iżda Google mgħaġġla ma ssuġġeriet l-ebda soluzzjonijiet, u ma kellix ħafna xewqa li nfittex f'aktar fond. Jew il-mod, huwa workout tajjeb.

Formalizzazzjoni tal-kompitu

Il-fajl tar-reġistru finali jikkonsisti f'ħafna linji ta' tul varjabbli. Grafikament, il-log file jista 'jiġi rappreżentat xi ħaġa bħal din:
Ittella’ log PostgreSQL mill-sħaba tal-AWS

Diġà tfakkarkom f'xi ħaġa? X'għandu x'jaqsam miegħu Tetris? U hawn x'għandha x'taqsam magħha.
Jekk nimmaġinaw l-għażliet possibbli li jinqalgħu meta tgħabbi l-fajl li jmiss b'mod grafiku (għal sempliċità, f'dan il-każ, ħalli l-linji jkollhom l-istess tul), inġibu Biċċiet Tetris standard:

1) Il-fajl jitniżżel fl-intier tiegħu u huwa finali. Id-daqs tal-porzjon huwa akbar mid-daqs finali tal-fajl:
Ittella’ log PostgreSQL mill-sħaba tal-AWS

2) Il-fajl ikompli. Id-daqs tal-biċċa huwa iżgħar mid-daqs finali tal-fajl:
Ittella’ log PostgreSQL mill-sħaba tal-AWS

3) Il-fajl huwa kontinwazzjoni tal-fajl preċedenti u għandu kontinwazzjoni. Id-daqs tal-biċċa huwa iżgħar mid-daqs tal-bqija tal-fajl finali:
Ittella’ log PostgreSQL mill-sħaba tal-AWS

4) Il-fajl huwa kontinwazzjoni tal-fajl preċedenti u huwa dak finali. Id-daqs tal-biċċa huwa akbar mid-daqs tal-bqija tal-fajl finali:
Ittella’ log PostgreSQL mill-sħaba tal-AWS

Il-kompitu huwa li tiġbor rettangolu jew tilgħab Tetris fuq livell ġdid.
Ittella’ log PostgreSQL mill-sħaba tal-AWS

Problemi li jinqalgħu waqt li tissolva problema

1) Kolla spaga ta '2 biċċiet

Ittella’ log PostgreSQL mill-sħaba tal-AWS
B'mod ġenerali, ma kienx hemm problemi speċjali. Problema standard minn kors inizjali ta 'programmazzjoni.

Daqs ottimali tas-servizz

Iżda dan huwa ftit aktar interessanti.
Sfortunatament, m'hemm l-ebda mod kif tuża offset wara t-tikketta tal-porzjon tal-bidu:

Kif diġà taf l-għażla —starting-token tintuża biex tispeċifika fejn tibda l-paġnar. Din l-għażla tieħu valuri String li jkun ifisser li jekk tipprova żżid valur ta 'offset quddiem is-sekwenza ta' Token Next, l-għażla ma titqiesx bħala offset.

U għalhekk, trid taqrah f'biċċiet.
Jekk taqra f'porzjonijiet kbar, in-numru ta 'qari jkun minimu, iżda l-volum ikun massimu.
Jekk taqra f'porzjonijiet żgħar, allura għall-kuntrarju, in-numru ta 'qari se jkun massimu, iżda l-volum se jkun minimu.
Għalhekk, biex inaqqas it-traffiku u għas-sbuħija ġenerali tas-soluzzjoni, kelli noħroġ b'soluzzjoni, li, sfortunatament, tidher xi ftit qisha crutch.

Għall-illustrazzjoni, ejja nikkunsidraw il-proċess tat-tniżżil ta 'log file f'2 verżjonijiet simplifikati ħafna. In-numru ta 'qari fiż-żewġ każijiet jiddependi mid-daqs tal-porzjon.

1) Tagħbija f'porzjonijiet żgħar:
Ittella’ log PostgreSQL mill-sħaba tal-AWS

2) Tagħbija f'porzjonijiet kbar:
Ittella’ log PostgreSQL mill-sħaba tal-AWS

Bħas-soltu, l-aħjar soluzzjoni hija fin-nofs.
Id-daqs tas-servizz huwa minimu, iżda matul il-proċess tal-qari, id-daqs jista 'jiżdied biex jitnaqqas in-numru ta' qari.

Għandu jiġi nnutat li l-problema tal-għażla tad-daqs ottimali tal-porzjon li jinqara għadha ma ġietx solvuta u teħtieġ studju u analiżi aktar fil-fond. Forsi ftit wara.

Deskrizzjoni ġenerali tal-implimentazzjoni

Tabelli tas-servizz użati

CREATE TABLE endpoint
(
id SERIAL ,
host text 
);

TABLE database
(
id SERIAL , 
…
last_aws_log_time text ,
last_aws_nexttoken text ,
aws_max_item_size integer 
);
last_aws_log_time — временная метка последнего загруженного лог-файла в формате YYYY-MM-DD-HH24.
last_aws_nexttoken — текстовая метка последней загруженной порции.
aws_max_item_size- эмпирическим путем, подобранный начальный размер порции.

Test b'kitba sħiħa

download_aws_piece.sh

#!/bin/bash
#########################################################
# download_aws_piece.sh
# downloan piece of log from AWS
# version HABR
 let min_item_size=1024
 let max_item_size=1048576
 let growth_factor=3
 let growth_counter=1
 let growth_counter_max=3

 echo $(date +%Y%m%d%H%M)':    download_aws_piece.sh:''STARTED'
 
 AWS_LOG_TIME=$1
 echo $(date +%Y%m%d%H%M)':    download_aws_piece.sh:AWS_LOG_TIME='$AWS_LOG_TIME
  
 database_id=$2
 echo $(date +%Y%m%d%H%M)':    download_aws_piece.sh:database_id='$database_id
 RESULT_FILE=$3 
  
 endpoint=`psql -h MONITOR_ENDPOINT.rds.amazonaws.com -U USER -d MONITOR_DATABASE_DATABASE -A -t -c "select e.host from endpoint e join database d on e.id = d.endpoint_id where d.id = $database_id "`
 echo $(date +%Y%m%d%H%M)':    download_aws_piece.sh:endpoint='$endpoint
  
 db_instance=`echo $endpoint | awk -F"." '{print toupper($1)}'`
 
 echo $(date +%Y%m%d%H%M)':    download_aws_piece.sh:db_instance='$db_instance

 LOG_FILE=$RESULT_FILE'.tmp_log'
 TMP_FILE=$LOG_FILE'.tmp'
 TMP_MIDDLE=$LOG_FILE'.tmp_mid'  
 TMP_MIDDLE2=$LOG_FILE'.tmp_mid2'  
  
 current_aws_log_time=`psql -h MONITOR_ENDPOINT.rds.amazonaws.com -U USER -d MONITOR_DATABASE -A -t -c "select last_aws_log_time from database where id = $database_id "`

 echo $(date +%Y%m%d%H%M)':      download_aws_piece.sh:current_aws_log_time='$current_aws_log_time
  
  if [[ $current_aws_log_time != $AWS_LOG_TIME  ]];
  then
    is_new_log='1'
	if ! psql -h MONITOR_ENDPOINT.rds.amazonaws.com -U USER -d MONITOR_DATABASE -v ON_ERROR_STOP=1 -A -t -q -c "update database set last_aws_log_time = '$AWS_LOG_TIME' where id = $database_id "
	then
	  echo $(date +%Y%m%d%H%M)':    download_aws_piece.sh: FATAL_ERROR - update database set last_aws_log_time .'
	  exit 1
	fi
  else
    is_new_log='0'
  fi
  
  echo $(date +%Y%m%d%H%M)':    download_aws_piece.sh:is_new_log='$is_new_log
  
  let last_aws_max_item_size=`psql -h MONITOR_ENDPOINT.rds.amazonaws.com -U USER -d MONITOR_DATABASE -A -t -c "select aws_max_item_size from database where id = $database_id "`
  echo $(date +%Y%m%d%H%M)':    download_aws_piece.sh: last_aws_max_item_size='$last_aws_max_item_size
  
  let count=1
  if [[ $is_new_log == '1' ]];
  then    
	echo $(date +%Y%m%d%H%M)':    download_aws_piece.sh: START DOWNLOADING OF NEW AWS LOG'
	if ! aws rds download-db-log-file-portion 
		--max-items $last_aws_max_item_size 
		--region REGION 
		--db-instance-identifier  $db_instance 
		--log-file-name error/postgresql.log.$AWS_LOG_TIME > $LOG_FILE
	then
		echo $(date +%Y%m%d%H%M)':    download_aws_piece.sh: FATAL_ERROR - Could not get log from AWS .'
		exit 2
	fi  	
  else
    next_token=`psql -h MONITOR_ENDPOINT.rds.amazonaws.com -U USER -d MONITOR_DATABASE -v ON_ERROR_STOP=1 -A -t -c "select last_aws_nexttoken from database where id = $database_id "`
	
	if [[ $next_token == '' ]];
	then
	  next_token='0'	  
	fi
	
	echo $(date +%Y%m%d%H%M)':    download_aws_piece.sh: CONTINUE DOWNLOADING OF AWS LOG'
	if ! aws rds download-db-log-file-portion 
	    --max-items $last_aws_max_item_size 
		--starting-token $next_token 
		--region REGION 
		--db-instance-identifier  $db_instance 
		--log-file-name error/postgresql.log.$AWS_LOG_TIME > $LOG_FILE
	then
		echo $(date +%Y%m%d%H%M)':    download_aws_piece.sh: FATAL_ERROR - Could not get log from AWS .'
		exit 3
	fi       
	
	line_count=`cat  $LOG_FILE | wc -l`
	let lines=$line_count-1
	  
	tail -$lines $LOG_FILE > $TMP_MIDDLE 
	mv -f $TMP_MIDDLE $LOG_FILE
  fi
  
  next_token_str=`cat $LOG_FILE | grep NEXTTOKEN` 
  next_token=`echo $next_token_str | awk -F" " '{ print $2}' `
  
  grep -v NEXTTOKEN $LOG_FILE  > $TMP_FILE 
  
  if [[ $next_token == '' ]];
  then
	  cp $TMP_FILE $RESULT_FILE
	  
	  echo $(date +%Y%m%d%H%M)':    download_aws_piece.sh:  NEXTTOKEN NOT FOUND - FINISH '
	  rm $LOG_FILE 
	  rm $TMP_FILE
	  rm $TMP_MIDDLE
          rm $TMP_MIDDLE2	  
	  exit 0  
  else
	psql -h MONITOR_ENDPOINT.rds.amazonaws.com -U USER -d MONITOR_DATABASE -v ON_ERROR_STOP=1 -A -t -q -c "update database set last_aws_nexttoken = '$next_token' where id = $database_id "
  fi
  
  first_str=`tail -1 $TMP_FILE`
  
  line_count=`cat  $TMP_FILE | wc -l`
  let lines=$line_count-1    
  
  head -$lines $TMP_FILE  > $RESULT_FILE

###############################################
# MAIN CIRCLE
  let count=2
  while [[ $next_token != '' ]];
  do 
    echo $(date +%Y%m%d%H%M)':    download_aws_piece.sh: count='$count
	
	echo $(date +%Y%m%d%H%M)':    download_aws_piece.sh: START DOWNLOADING OF AWS LOG'
	if ! aws rds download-db-log-file-portion 
             --max-items $last_aws_max_item_size 
             --starting-token $next_token 
             --region REGION 
             --db-instance-identifier  $db_instance 
             --log-file-name error/postgresql.log.$AWS_LOG_TIME > $LOG_FILE
	then
		echo $(date +%Y%m%d%H%M)':    download_aws_piece.sh: FATAL_ERROR - Could not get log from AWS .'
		exit 4
	fi

	next_token_str=`cat $LOG_FILE | grep NEXTTOKEN` 
	next_token=`echo $next_token_str | awk -F" " '{ print $2}' `

	TMP_FILE=$LOG_FILE'.tmp'
	grep -v NEXTTOKEN $LOG_FILE  > $TMP_FILE  
	
	last_str=`head -1 $TMP_FILE`
  
    if [[ $next_token == '' ]];
	then
	  concat_str=$first_str$last_str
	  	  
	  echo $concat_str >> $RESULT_FILE
		 
	  line_count=`cat  $TMP_FILE | wc -l`
	  let lines=$line_count-1
	  
	  tail -$lines $TMP_FILE >> $RESULT_FILE
	  
	  echo $(date +%Y%m%d%H%M)':    download_aws_piece.sh:  NEXTTOKEN NOT FOUND - FINISH '
	  rm $LOG_FILE 
	  rm $TMP_FILE
	  rm $TMP_MIDDLE
          rm $TMP_MIDDLE2	  
	  exit 0  
	fi
	
    if [[ $next_token != '' ]];
	then
		let growth_counter=$growth_counter+1
		if [[ $growth_counter -gt $growth_counter_max ]];
		then
			let last_aws_max_item_size=$last_aws_max_item_size*$growth_factor
			let growth_counter=1
		fi
	
		if [[ $last_aws_max_item_size -gt $max_item_size ]]; 
		then
			let last_aws_max_item_size=$max_item_size
		fi 

	  psql -h MONITOR_ENDPOINT.rds.amazonaws.com -U USER -d MONITOR_DATABASE -A -t -q -c "update database set last_aws_nexttoken = '$next_token' where id = $database_id "
	  
	  concat_str=$first_str$last_str
	  	  
	  echo $concat_str >> $RESULT_FILE
		 
	  line_count=`cat  $TMP_FILE | wc -l`
	  let lines=$line_count-1
	  
	  #############################
	  #Get middle of file
	  head -$lines $TMP_FILE > $TMP_MIDDLE
	  
	  line_count=`cat  $TMP_MIDDLE | wc -l`
	  let lines=$line_count-1
	  tail -$lines $TMP_MIDDLE > $TMP_MIDDLE2
	  
	  cat $TMP_MIDDLE2 >> $RESULT_FILE	  
	  
	  first_str=`tail -1 $TMP_FILE`	  
	fi
	  
    let count=$count+1

  done
#
#################################################################

exit 0

Frammenti tal-kitba b'xi spjegazzjonijiet:

Parametri tad-dħul tal-iskript:

  • Timestamp tal-isem tal-fajl log fil-format SSSS-MM-JJ-HH24: AWS_LOG_TIME=$1
  • ID tad-database: database_id=$2
  • Isem tal-log file miġbur: RESULT_FILE=$3

Ikseb it-timestamp tal-aħħar log file mgħobbi:

current_aws_log_time=`psql -h MONITOR_ENDPOINT.rds.amazonaws.com -U USER -d MONITOR_DATABASE -A -t -c "select last_aws_log_time from database where id = $database_id "`

Jekk il-timestamp tal-aħħar log file mgħobbi ma jaqbilx mal-parametru tal-input, jitgħabba log fajl ġdid:

if [[ $current_aws_log_time != $AWS_LOG_TIME  ]];
  then
    is_new_log='1'
	if ! psql -h ENDPOINT.rds.amazonaws.com -U USER -d MONITOR_DATABASE -v ON_ERROR_STOP=1 -A -t -c "update database set last_aws_log_time = '$AWS_LOG_TIME' where id = $database_id "
	then
	  echo '***download_aws_piece.sh -FATAL_ERROR - update database set last_aws_log_time .'
	  exit 1
	fi
  else
    is_new_log='0'
  fi

Nieħdu l-valur tat-tikketta nexttoken mill-fajl imniżżel:

  next_token_str=`cat $LOG_FILE | grep NEXTTOKEN` 
  next_token=`echo $next_token_str | awk -F" " '{ print $2}' `

Valur nexttoken vojt iservi bħala sinjal tat-tmiem tat-tniżżil.

F'linja, ngħoddu porzjonijiet tal-fajl, nikkonkatenaw il-linji tul it-triq u nżidu d-daqs tal-porzjon:
Loop prinċipali

# MAIN CIRCLE
  let count=2
  while [[ $next_token != '' ]];
  do 
    echo $(date +%Y%m%d%H%M)':    download_aws_piece.sh: count='$count
	
	echo $(date +%Y%m%d%H%M)':    download_aws_piece.sh: START DOWNLOADING OF AWS LOG'
	if ! aws rds download-db-log-file-portion 
     --max-items $last_aws_max_item_size 
	 --starting-token $next_token 
     --region REGION 
     --db-instance-identifier  $db_instance 
     --log-file-name error/postgresql.log.$AWS_LOG_TIME > $LOG_FILE
	then
		echo $(date +%Y%m%d%H%M)':    download_aws_piece.sh: FATAL_ERROR - Could not get log from AWS .'
		exit 4
	fi

	next_token_str=`cat $LOG_FILE | grep NEXTTOKEN` 
	next_token=`echo $next_token_str | awk -F" " '{ print $2}' `

	TMP_FILE=$LOG_FILE'.tmp'
	grep -v NEXTTOKEN $LOG_FILE  > $TMP_FILE  
	
	last_str=`head -1 $TMP_FILE`
  
    if [[ $next_token == '' ]];
	then
	  concat_str=$first_str$last_str
	  	  
	  echo $concat_str >> $RESULT_FILE
		 
	  line_count=`cat  $TMP_FILE | wc -l`
	  let lines=$line_count-1
	  
	  tail -$lines $TMP_FILE >> $RESULT_FILE
	  
	  echo $(date +%Y%m%d%H%M)':    download_aws_piece.sh:  NEXTTOKEN NOT FOUND - FINISH '
	  rm $LOG_FILE 
	  rm $TMP_FILE
	  rm $TMP_MIDDLE
         rm $TMP_MIDDLE2	  
	  exit 0  
	fi
	
    if [[ $next_token != '' ]];
	then
		let growth_counter=$growth_counter+1
		if [[ $growth_counter -gt $growth_counter_max ]];
		then
			let last_aws_max_item_size=$last_aws_max_item_size*$growth_factor
			let growth_counter=1
		fi
	
		if [[ $last_aws_max_item_size -gt $max_item_size ]]; 
		then
			let last_aws_max_item_size=$max_item_size
		fi 

	  psql -h MONITOR_ENDPOINT.rds.amazonaws.com -U USER -d MONITOR_DATABASE -A -t -q -c "update database set last_aws_nexttoken = '$next_token' where id = $database_id "
	  
	  concat_str=$first_str$last_str
	  	  
	  echo $concat_str >> $RESULT_FILE
		 
	  line_count=`cat  $TMP_FILE | wc -l`
	  let lines=$line_count-1
	  
	  #############################
	  #Get middle of file
	  head -$lines $TMP_FILE > $TMP_MIDDLE
	  
	  line_count=`cat  $TMP_MIDDLE | wc -l`
	  let lines=$line_count-1
	  tail -$lines $TMP_MIDDLE > $TMP_MIDDLE2
	  
	  cat $TMP_MIDDLE2 >> $RESULT_FILE	  
	  
	  first_str=`tail -1 $TMP_FILE`	  
	fi
	  
    let count=$count+1

  done

X'inhu jmiss?

Għalhekk, l-ewwel kompitu intermedju - "niżżel fajl tal-ġurnal mis-sħaba" ġie solvut. X'għandek tagħmel bil-log imniżżel?
L-ewwel, għandek bżonn teżamina l-fajl tal-ġurnal u tiġbed it-talbiet attwali minnu.
Il-kompitu mhuwiex diffiċli ħafna. L-iskript bash l-aktar sempliċi jagħmel ix-xogħol pjuttost tajjeb.
upload_log_query.sh

#!/bin/bash
#########################################################
# upload_log_query.sh
# Upload table table from dowloaded aws file 
# version HABR
###########################################################  
echo 'TIMESTAMP:'$(date +%c)' Upload log_query table '
source_file=$1
echo 'source_file='$source_file
database_id=$2
echo 'database_id='$database_id

beginer=' '
first_line='1'
let "line_count=0"
sql_line=' '
sql_flag=' '    
space=' '
cat $source_file | while read line
do
  line="$space$line"

  if [[ $first_line == "1" ]]; then
    beginer=`echo $line | awk -F" " '{ print $1}' `
    first_line='0'
  fi

  current_beginer=`echo $line | awk -F" " '{ print $1}' `

  if [[ $current_beginer == $beginer ]]; then
    if [[ $sql_flag == '1' ]]; then
     sql_flag='0' 
     log_date=`echo $sql_line | awk -F" " '{ print $1}' `
     log_time=`echo $sql_line | awk -F" " '{ print $2}' `
     duration=`echo $sql_line | awk -F" " '{ print $5}' `

     #replace ' to ''
     sql_modline=`echo "$sql_line" | sed 's/'''/''''''/g'`
     sql_line=' '

	 ################
	 #PROCESSING OF THE SQL-SELECT IS HERE
     if ! psql -h ENDPOINT.rds.amazonaws.com -U USER -d DATABASE -v ON_ERROR_STOP=1 -A -t -c "select log_query('$ip_port',$database_id , '$log_date' , '$log_time' , '$duration' , '$sql_modline' )" 
     then
        echo 'FATAL_ERROR - log_query '
        exit 1
     fi
	 ################

    fi #if [[ $sql_flag == '1' ]]; then

    let "line_count=line_count+1"

    check=`echo $line | awk -F" " '{ print $8}' `
    check_sql=${check^^}    

    #echo 'check_sql='$check_sql
    
    if [[ $check_sql == 'SELECT' ]]; then
     sql_flag='1'    
     sql_line="$sql_line$line"
	 ip_port=`echo $sql_line | awk -F":" '{ print $4}' `
    fi
  else       

    if [[ $sql_flag == '1' ]]; then
      sql_line="$sql_line$line"
    fi   
    
  fi #if [[ $current_beginer == $beginer ]]; then

done

Issa tista 'taħdem bit-talba magħżula mill-fajl log.

U jinfetħu diversi opportunitajiet utli.

Mistoqsijiet parsed jeħtieġ li jinħażnu x'imkien. Għal dan tintuża tabella tas-servizz log_query

CREATE TABLE log_query
(
   id SERIAL ,
   queryid bigint ,
   query_md5hash text not null ,
   database_id integer not null ,  
   timepoint timestamp without time zone not null,
   duration double precision not null ,
   query text not null ,
   explained_plan text[],
   plan_md5hash text  , 
   explained_plan_wo_costs text[],
   plan_hash_value text  ,
   baseline_id integer ,
   ip text ,
   port text 
);
ALTER TABLE log_query ADD PRIMARY KEY (id);
ALTER TABLE log_query ADD CONSTRAINT queryid_timepoint_unique_key UNIQUE (queryid, timepoint );
ALTER TABLE log_query ADD CONSTRAINT query_md5hash_timepoint_unique_key UNIQUE (query_md5hash, timepoint );

CREATE INDEX log_query_timepoint_idx ON log_query (timepoint);
CREATE INDEX log_query_queryid_idx ON log_query (queryid);
ALTER TABLE log_query ADD CONSTRAINT database_id_fk FOREIGN KEY (database_id) REFERENCES database (id) ON DELETE CASCADE ;

It-talba parsed tiġi pproċessata fi plpgsql funzjonijiet "log_query".
log_query.sql

--log_query.sql
--verison HABR
CREATE OR REPLACE FUNCTION log_query( ip_port text ,log_database_id integer , log_date text , log_time text , duration text , sql_line text   ) RETURNS boolean AS $$
DECLARE
  result boolean ;
  log_timepoint timestamp without time zone ;
  log_duration double precision ; 
  pos integer ;
  log_query text ;
  activity_string text ;
  log_md5hash text ;
  log_explain_plan text[] ;
  
  log_planhash text ;
  log_plan_wo_costs text[] ; 
  
  database_rec record ;
  
  pg_stat_query text ; 
  test_log_query text ;
  log_query_rec record;
  found_flag boolean;
  
  pg_stat_history_rec record ;
  port_start integer ;
  port_end integer ;
  client_ip text ;
  client_port text ;
  log_queryid bigint ;
  log_query_text text ;
  pg_stat_query_text text ; 
BEGIN
  result = TRUE ;

  RAISE NOTICE '***log_query';
  
  port_start = position('(' in ip_port);
  port_end = position(')' in ip_port);
  client_ip = substring( ip_port from 1 for port_start-1 );
  client_port = substring( ip_port from port_start+1 for port_end-port_start-1 );

  SELECT e.host , d.name , d.owner_pwd 
  INTO database_rec
  FROM database d JOIN endpoint e ON e.id = d.endpoint_id
  WHERE d.id = log_database_id ;
  
  log_timepoint = to_timestamp(log_date||' '||log_time,'YYYY-MM-DD HH24-MI-SS');
  log_duration = duration:: double precision; 

  
  pos = position ('SELECT' in UPPER(sql_line) );
  log_query = substring( sql_line from pos for LENGTH(sql_line));
  log_query = regexp_replace(log_query,' +',' ','g');
  log_query = regexp_replace(log_query,';+','','g');
  log_query = trim(trailing ' ' from log_query);
 

  log_md5hash = md5( log_query::text );
  
  --Explain execution plan--
  EXECUTE 'SELECT dblink_connect(''LINK1'',''host='||database_rec.host||' dbname='||database_rec.name||' user=DATABASE password='||database_rec.owner_pwd||' '')'; 
  
  log_explain_plan = ARRAY ( SELECT * FROM dblink('LINK1', 'EXPLAIN '||log_query ) AS t (plan text) );
  log_plan_wo_costs = ARRAY ( SELECT * FROM dblink('LINK1', 'EXPLAIN ( COSTS FALSE ) '||log_query ) AS t (plan text) );
    
  PERFORM dblink_disconnect('LINK1');
  --------------------------
  BEGIN
	INSERT INTO log_query
	(
		query_md5hash ,
		database_id , 
		timepoint ,
		duration ,
		query ,
		explained_plan ,
		plan_md5hash , 
		explained_plan_wo_costs , 
		plan_hash_value , 
		ip , 
		port
	) 
	VALUES 
	(
		log_md5hash ,
		log_database_id , 
		log_timepoint , 
		log_duration , 
		log_query ,
		log_explain_plan , 
		md5(log_explain_plan::text) ,
		log_plan_wo_costs , 
		md5(log_plan_wo_costs::text),
		client_ip , 
		client_port		
	);
	activity_string = 	'New query has logged '||
						' database_id = '|| log_database_id ||
						' query_md5hash='||log_md5hash||
						' , timepoint = '||to_char(log_timepoint,'YYYYMMDD HH24:MI:SS');
					
	RAISE NOTICE '%',activity_string;					
					 
	PERFORM pg_log( log_database_id , 'log_query' , activity_string);  

	EXCEPTION
	  WHEN unique_violation THEN
		RAISE NOTICE '*** unique_violation *** query already has logged';
	END;

	SELECT 	queryid
	INTO   	log_queryid
	FROM 	log_query 
	WHERE 	query_md5hash = log_md5hash AND
			timepoint = log_timepoint;

	IF log_queryid IS NOT NULL 
	THEN 
	  RAISE NOTICE 'log_query with query_md5hash = % and timepoint = % has already has a QUERYID = %',log_md5hash,log_timepoint , log_queryid ;
	  RETURN result;
	END IF;
	
	------------------------------------------------
	RAISE NOTICE 'Update queryid';	
	
	SELECT * 
	INTO log_query_rec
	FROM log_query
	WHERE query_md5hash = log_md5hash AND timepoint = log_timepoint ; 
	
	log_query_rec.query=regexp_replace(log_query_rec.query,';+','','g');
	
	FOR pg_stat_history_rec IN
	 SELECT 
         queryid ,
	  query 
	 FROM 
         pg_stat_db_queries 
     WHERE  
      database_id = log_database_id AND
       queryid is not null 
	LOOP
	  pg_stat_query = pg_stat_history_rec.query ; 
	  pg_stat_query=regexp_replace(pg_stat_query,'n+',' ','g');
	  pg_stat_query=regexp_replace(pg_stat_query,'t+',' ','g');
	  pg_stat_query=regexp_replace(pg_stat_query,' +',' ','g');
	  pg_stat_query=regexp_replace(pg_stat_query,'$.','%','g');
	
	  log_query_text = trim(trailing ' ' from log_query_rec.query);
	  pg_stat_query_text = pg_stat_query; 
	
	  
	  --SELECT log_query_rec.query like pg_stat_query INTO found_flag ; 
	  IF (log_query_text LIKE pg_stat_query_text) THEN
		found_flag = TRUE ;
	  ELSE
		found_flag = FALSE ;
	  END IF;	  
	  
	  
	  IF found_flag THEN
	    
		UPDATE log_query SET queryid = pg_stat_history_rec.queryid WHERE query_md5hash = log_md5hash AND timepoint = log_timepoint ;
		activity_string = 	' updated queryid = '||pg_stat_history_rec.queryid||
		                    ' for log_query with id = '||log_query_rec.id               
		   				    ;						
	    RAISE NOTICE '%',activity_string;	
		EXIT ;
	  END IF ;
	  
	END LOOP ;
	
  RETURN result ;
END
$$ LANGUAGE plpgsql;

Tabella tas-servizz tintuża waqt l-ipproċessar pg_stat_db_queries, li fih stampa ta' mistoqsijiet kurrenti mit-tabella pg_stat_history (L-użu tat-tabella huwa deskritt hawn − Monitoraġġ tal-prestazzjoni tal-mistoqsijiet PostgreSQL. Parti 1 - rappurtar)

TABLE pg_stat_db_queries
(
   database_id integer,  
   queryid bigint ,  
   query text , 
   max_time double precision 
);


TABLE pg_stat_history 
(
…
database_id integer ,
…
queryid bigint ,
…
max_time double precision	 , 	
…
);

Il-funzjoni tippermettilek li timplimenta numru ta 'kapaċitajiet utli għall-ipproċessar ta' talbiet minn fajl log. Jiġifieri:

Opportunità #1 - Mistoqsija l-istorja tal-eżekuzzjoni

Utli ħafna biex tibda ssolvi inċident ta' prestazzjoni. L-ewwel, jiffamiljarizzaw ruħhom mal-istorja - meta beda t-tnaqqis?
Imbagħad, skond il-klassiċi, tfittex raġunijiet esterni. Forsi t-tagħbija tad-database sempliċement żdiedet drastikament u t-talba speċifika m'għandha x'taqsam xejn magħha.
Żid dħul ġdid fit-tabella log_query

  port_start = position('(' in ip_port);
  port_end = position(')' in ip_port);
  client_ip = substring( ip_port from 1 for port_start-1 );
  client_port = substring( ip_port from port_start+1 for port_end-port_start-1 );

  SELECT e.host , d.name , d.owner_pwd 
  INTO database_rec
  FROM database d JOIN endpoint e ON e.id = d.endpoint_id
  WHERE d.id = log_database_id ;
  
  log_timepoint = to_timestamp(log_date||' '||log_time,'YYYY-MM-DD HH24-MI-SS');
  log_duration = to_number(duration,'99999999999999999999D9999999999'); 

  
  pos = position ('SELECT' in UPPER(sql_line) );
  log_query = substring( sql_line from pos for LENGTH(sql_line));
  log_query = regexp_replace(log_query,' +',' ','g');
  log_query = regexp_replace(log_query,';+','','g');
  log_query = trim(trailing ' ' from log_query);
 
  RAISE NOTICE 'log_query=%',log_query ;   

  log_md5hash = md5( log_query::text );
  
  --Explain execution plan--
  EXECUTE 'SELECT dblink_connect(''LINK1'',''host='||database_rec.host||' dbname='||database_rec.name||' user=DATABASE password='||database_rec.owner_pwd||' '')'; 
  
  log_explain_plan = ARRAY ( SELECT * FROM dblink('LINK1', 'EXPLAIN '||log_query ) AS t (plan text) );
  log_plan_wo_costs = ARRAY ( SELECT * FROM dblink('LINK1', 'EXPLAIN ( COSTS FALSE ) '||log_query ) AS t (plan text) );
    
  PERFORM dblink_disconnect('LINK1');
  --------------------------
  BEGIN
	INSERT INTO log_query
	(
		query_md5hash ,
		database_id , 
		timepoint ,
		duration ,
		query ,
		explained_plan ,
		plan_md5hash , 
		explained_plan_wo_costs , 
		plan_hash_value , 
		ip , 
		port
	) 
	VALUES 
	(
		log_md5hash ,
		log_database_id , 
		log_timepoint , 
		log_duration , 
		log_query ,
		log_explain_plan , 
		md5(log_explain_plan::text) ,
		log_plan_wo_costs , 
		md5(log_plan_wo_costs::text),
		client_ip , 
		client_port		
	);

Possibbiltà #2 - Issejvja l-pjanijiet ta 'eżekuzzjoni tal-mistoqsijiet

F’dan il-punt jista’ jqum oġġezzjoni-kjarifika-kumment: “Imma diġà hemm autoexplain" Iva, qiegħed hemm, imma x'inhu l-punt jekk il-pjan ta 'eżekuzzjoni jinħażen fl-istess fajl tal-ġurnal u sabiex issalvah għal aktar analiżi, għandek teżamina l-fajl tal-ġurnal?

Dak li kelli bżonn kien:
l-ewwel: aħżen il-pjan ta 'eżekuzzjoni fit-tabella tas-servizz tad-database ta' monitoraġġ;
it-tieni: biex tkun tista 'tqabbel il-pjanijiet ta' eżekuzzjoni ma 'xulxin sabiex immedjatament tara li l-pjan ta' eżekuzzjoni tal-mistoqsijiet inbidel.

Hemm talba b'parametri ta' eżekuzzjoni speċifiċi. Il-ksib u l-iffrankar tal-pjan ta 'eżekuzzjoni tiegħu bl-użu ta' EXPLAIN huwa kompitu elementari.
Barra minn hekk, billi tuża l-espressjoni SPJEGA (SPEJJEŻ FALZI), tista 'tikseb skeletru tal-pjan, li se jintuża biex jikseb il-valur hash tal-pjan, li jgħin fl-analiżi sussegwenti tal-istorja tal-bidliet fil-pjan ta' eżekuzzjoni.
Ikseb il-mudell tal-pjan ta 'eżekuzzjoni

  --Explain execution plan--
  EXECUTE 'SELECT dblink_connect(''LINK1'',''host='||database_rec.host||' dbname='||database_rec.name||' user=DATABASE password='||database_rec.owner_pwd||' '')'; 
  
  log_explain_plan = ARRAY ( SELECT * FROM dblink('LINK1', 'EXPLAIN '||log_query ) AS t (plan text) );
  log_plan_wo_costs = ARRAY ( SELECT * FROM dblink('LINK1', 'EXPLAIN ( COSTS FALSE ) '||log_query ) AS t (plan text) );
    
  PERFORM dblink_disconnect('LINK1');

Possibbiltà #3 - L-użu tar-reġistru tal-mistoqsijiet għall-monitoraġġ

Peress li l-metriċi tal-prestazzjoni huma kkonfigurati mhux fuq it-test tat-talba, iżda fuq l-ID tagħha, għandek bżonn tassoċja talbiet mill-fajl log ma 'talbiet li għalihom il-metriċi tal-prestazzjoni huma kkonfigurati.
Ukoll, għall-inqas sabiex ikun hemm il-ħin eżatt ta 'okkorrenza ta' inċident ta 'prestazzjoni.

Dan il-mod, meta jseħħ inċident ta’ prestazzjoni għal ID ta’ talba, ikun hemm link għal talba speċifika b’valuri ta’ parametri speċifiċi u l-ħin eżatt ta’ eżekuzzjoni u t-tul tat-talba. Ikseb din l-informazzjoni billi tuża biss il-veduta pg_stat_statements - huwa pprojbit.
Sib il-queryid tat-talba u aġġorna l-entrata fit-tabella log_query

SELECT * 
	INTO log_query_rec
	FROM log_query
	WHERE query_md5hash = log_md5hash AND timepoint = log_timepoint ; 
	
	log_query_rec.query=regexp_replace(log_query_rec.query,';+','','g');
	
	FOR pg_stat_history_rec IN
	 SELECT 
      queryid ,
	  query 
	 FROM 
       pg_stat_db_queries 
     WHERE  
	   database_id = log_database_id AND
       queryid is not null 
	LOOP
	  pg_stat_query = pg_stat_history_rec.query ; 
	  pg_stat_query=regexp_replace(pg_stat_query,'n+',' ','g');
	  pg_stat_query=regexp_replace(pg_stat_query,'t+',' ','g');
	  pg_stat_query=regexp_replace(pg_stat_query,' +',' ','g');
	  pg_stat_query=regexp_replace(pg_stat_query,'$.','%','g');
	
	  log_query_text = trim(trailing ' ' from log_query_rec.query);
	  pg_stat_query_text = pg_stat_query; 
	  
	  --SELECT log_query_rec.query like pg_stat_query INTO found_flag ; 
	  IF (log_query_text LIKE pg_stat_query_text) THEN
		found_flag = TRUE ;
	  ELSE
		found_flag = FALSE ;
	  END IF;	  
	  
	  
	  IF found_flag THEN
	    
		UPDATE log_query SET queryid = pg_stat_history_rec.queryid WHERE query_md5hash = log_md5hash AND timepoint = log_timepoint ;
		activity_string = 	' updated queryid = '||pg_stat_history_rec.queryid||
		                    ' for log_query with id = '||log_query_rec.id		                    
		   				    ;						
					
	    RAISE NOTICE '%',activity_string;	
		EXIT ;
	  END IF ;
	  
	END LOOP ;

Wara kelma

It-teknika deskritta eventwalment sabet applikazzjoni fi is-sistema ta' monitoraġġ tal-prestazzjoni tal-mistoqsijiet PostgreSQL żviluppata, li jippermettilek li jkollok aktar informazzjoni biex tanalizza meta ssolvi inċidenti emerġenti tal-prestazzjoni tal-mistoqsijiet.

Għalkemm, ovvjament, fl-opinjoni personali tiegħi, ikun meħtieġ li taħdem aktar fuq l-algoritmu għall-għażla u l-bidla tad-daqs tal-porzjon imniżżel. Il-problema għadha ma ġietx solvuta fil-każ ġenerali. Probabbilment se jkun interessanti.

Imma dik hija storja kompletament differenti...

Sors: www.habr.com

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