Como um complemento curto ao artigo .
Tarefa
É necessário vincular o histórico das visualizações pg_stat_statements e pg_stat_activity. Como resultado, usando o histórico dos planos de execução da tabela de serviço log_query, pode-se obter muitas informações úteis para serem utilizadas no processo de resolução de incidentes de desempenho e otimização de consultas.
Aviso.
Devido à continuidade dos testes e do desenvolvimento, o artigo não pode ser considerado uma descrição de uma solução industrial pronta.
Críticas e comentários sobre a implementação são bem-vindos e esperados.
Dados de entrada
Tabela history_pg_stat_activity
--ACTIVITY_HIST.HISTORY_PG_STAT_ACTIVITY
DROP TABLE IF EXISTS activity_hist.history_pg_stat_activity;
CREATE TABLE activity_hist.history_pg_stat_activity
(
timepoint timestamp without time zone ,
datid oid ,
datname name ,
pid integer,
usesysid oid ,
usename name ,
application_name text ,
client_addr inet ,
client_hostname text ,
client_port integer,
backend_start timestamp without time zone ,
xact_start timestamp without time zone ,
query_start timestamp without time zone ,
state_change timestamp without time zone ,
wait_event_type text ,
wait_event text ,
state text ,
backend_xid xid ,
backend_xmin xid ,
query text ,
backend_type text ,
queryid bigint
);Tabela pg_stat_db_queries
CREATE TABLE pg_stat_db_queries
(
database_id integer ,
queryid bigint ,
query text ,
max_time double precision
);Visão materializada mvw_pg_stat_queries
CREATE MATERIALIZED VIEW public.mvw_pg_stat_queries AS
SELECT t.queryid,
t.max_time,
t.query
FROM public.dblink('LINK1'::text, 'SELECT queryid , max_time , query FROM pg_stat_statements WHERE dbid=(SELECT oid FROM pg_database WHERE datname=current_database() ) AND max_time >= 0 '::text) t(queryid bigint, max_time double precision, query text)
WITH NO DATA;
Tabela log_query
CREATE TABLE log_query
(
id integer ,
queryid bigint ,
query_md5hash text ,
database_id integer ,
timepoint timestamp without time zone ,
query text ,
explained_plan text[] ,
plan_md5hash text ,
explained_plan_wo_costs text[] ,
plan_hash_value text ,
ip text,
port text ,
pid integer
);Algoritmo geral
Atualizar a tabela pg_stat_db_queries
Atualizar a visão materializada mvw_pg_stat_queries
CRIE OU SUBSTITUA A FUNÇÃO refresh_pg_stat_queries_list( database_id int) RETORNA BOOLEAN AS $$
DECLARE
result BOOLEAN ;
database_rec record ;
BEGIN
SELECIONE *
INTO database_rec
DE endpoint e JUNTE database d ON e.id = d.endpoint_id
ONDE d.id = database_id ;
SE NÃO database_rec.is_need_monitoring ENTÃO RAISE NOTICE 'NÃO HÁ NECESSIDADE DE MONITORAMENTO PARA database_id=%',database_id; retornará TRUE ; FIM SE ;
EXECUTE 'SELECT dblink_connect(''LINK1'',''host='||database_rec.host||' port=5432 dbname='||database_rec.name||
' user='||database_rec.s_name||' password='||database_rec.s_pass|| ' '')';
ATUALIZAR MATERIALIZED VIEW mvw_pg_stat_queries ;
PERFORM dblink_disconnect('LINK1');
RETORNAR result;
FIM
$$ LINGUAGEM plpgsql;Preencher a tabela pg_stat_db_queries
CRIE OU SUBSTITUA A FUNÇÃO refresh_pg_stat_db_queries( ) RETORNA BOOLEAN AS $$
DECLARE
result BOOLEAN ;
database_rec record ;
pg_stat_rec record ;
BEGIN
TRUNCAR pg_stat_db_queries;
PARA database_rec EM
SELECIONE *
DE database d
LOOP
SE NÃO database_rec.is_need_monitoring ENTÃO RAISE NOTICE 'NÃO HÁ NECESSIDADE DE MONITORAMENTO PARA database_id=%',database_rec.id; CONTINUAR ; FIM SE ;
PERFORM refresh_pg_stat_queries_list( database_rec.id ) ;
PARA pg_stat_rec EM
SELECIONE *
DE mvw_pg_stat_queries
LOOP
INSERIR EM pg_stat_db_queries
( database_id , queryid , query , max_time )
VALORES
( database_rec.id , pg_stat_rec.queryid , pg_stat_rec.query , pg_stat_rec.max_time);
FIM LOOP;
FIM LOOP;
RETORNAR TRUE;
FIM
$$ LINGUAGEM plpgsql;Como resultado, a tabela contém textos normalizados de consultas, queryid, tempo máximo de execução da consulta no momento atual (usado para monitoramento).
Preenchendo log_query e formando o histórico dos planos de execução.
O texto atual da consulta é obtido do arquivo de log. O arquivo de log do host de destino para o host de monitoramento é transferido em partes, via script bash, através de cron. Para economizar espaço e devido à trivialidade da tarefa de copiar um pedaço de arquivo de texto de um host para outro, o script não é fornecido.
Análise do arquivo de log e extração do texto da consulta
#!/bin/bash
#########################################################
# upload_log_query.sh
# Upload table table from dowloaded aws file
# version 12.0
###########################################################
echo 'TIMESTAMP:'$(date +%c)' Upload log_query table '
source_file=$1
echo 'source_file='$source_file
database_id=$2
echo 'database_id='$database_id
database_name=$3
echo 'database_name='$database_name
beginer=' '
first_line='1'
let "line_count=0"
sql_line=' '
sql_flag=' '
space=' '
cat $source_file | while read line
do
#first line will be passed
if [[ $line_count == '0' ]]; then
let "line_count++"
continue
fi
line="$space$line"
#echo 'line='$line
if [[ $first_line == "1" ]]; then
beginer=`echo $line | awk -F" " '{ print $1}' `
first_line='0'
fi
current_beginer=`echo $line | awk -F" " '{ print $1}' `
#echo 'current_beginer='$current_beginer
#echo 'beginer='$beginer
if [[ $current_beginer == $beginer ]]; then
if [[ $sql_flag == '1' ]]; then
sql_flag='0'
#echo 'TIMESTAMP:'$(date +%c)' Upload log_query table : SQL STATEMENT ='"$sql_line"
log_date=`echo $sql_line | awk -F" " '{ print $1}' `
#echo 'log_date='$log_date
log_time=`echo $sql_line | awk -F" " '{ print $2}' `
#echo 'log_time='$log_time
duration=`echo $sql_line | awk -F" " '{ print $5}' `
#echo 'duration='$duration
connect=`echo $sql_line | awk -F" " '{ print $3}' `
userdb=`echo $connect | awk -F":" '{ print $3}' `
userdb2=$userdb'@'
db_port_log=`echo $connect | awk -F"@" '{ print $2}' `
log_database_name=`echo $db_port_log | awk -F":" '{ print $1}' `
#echo 'connect='$connect
#echo 'userdb='$userdb
#echo 'userdb2='$userdb2
#echo 'db_port_log='$db_port_log
#echo 'log_database_name='$log_database_name
if [[ "$log_database_name" != "$database_name" ]];
then
echo '*** database_name '$log_database_name' from log is not equal '$database_name' CONTINUE '
continue;
fi
#replace ' to ''
sql_modline=`echo "$sql_line" | sed 's/'''/''''''/g'`
sql_line=' '
#echo '*********************************log_query start'
#echo 'pid_str='$pid_str
#echo 'ip_port='$ip_port
#echo 'database_id='$database_id
#echo 'log_date='$log_date
#echo 'log_time='$log_time
#echo 'duration='$duration
#echo 'sql_modline='$sql_modline
if ! psql -U monitor -d monitor -v ON_ERROR_STOP=1 -A -t -q -c "select log_query( '$pid_str' , '$ip_port' , $database_id , '$log_date' , '$log_time' , '$duration' , '$sql_modline' )"
then
echo 'FATAL_ERROR - log_query '
exit 1
fi
#echo '**********************************log_query finish'
fi #if [[ $sql_flag == '1' ]]; then
let "line_count=line_count+1"
#echo 'line_count= '$line_count
#echo $line
#check=`echo $line | awk -F" " '{ print $8}' `
#check_sql=${check^^}
#echo 'check_sql='$check_sql
if [[ ${line^^} =~ "SELECT" ]];
then
if [[ $line =~ "duration:" ]];
then
test_statement=`echo $line | awk -F" " '{ print $8}'`
is_select=${test_statement^^}
#echo 'test_statement='$test_statement
#echo 'is_select='$is_select
if [[ $is_select == 'SELECT' ]];
then
sql_flag='1'
sql_line="$sql_line$line"
ip_port=`echo $sql_line | awk -F":" '{ print $4}' `
pid_str=`echo $sql_line | awk -F":" '{ print $6}' `
fi
fi
fi
else
#echo $line
#echo 'sql_flag ='$sql_flag
if [[ $sql_flag == '1' ]]; then
sql_line="$sql_line$line"
fi
fi #if [[ $current_beginer == $beginer ]]; then
donePreencher a tabela log_query
--log_query.sql
--inserir nova consulta na tabela log_query
CREATE OR REPLACE FUNCTION log_query( pid_str text , 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 ;
metric_rec record;
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 ;
current_pid_str text ;
current_pid integer;
pid_start_pos integer ;
pid_finish_pos integer ;
BEGIN
result = TRUE ;
IF ip_port != '[local]' THEN
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 );
ELSE
client_ip = 'local';
client_port = 'local';
END IF;
pid_start_pos = position('[' in pid_str);
pid_finish_pos = position(']' in pid_str);
current_pid_str=substring( pid_str from 2 for pid_finish_pos - pid_start_pos -1 );
current_pid = to_number(current_pid_str , '999999999999');
SELECT e.host , d.name , d.owner_pwd , d.owner_user
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 );
--Explicar plano de execução--
EXECUTE 'SELECT dblink_connect(''LINK1'',''host='||database_rec.host||' port=5432 dbname='||database_rec.name||' user='||database_rec.owner_user||' 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 ,
pid
)
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 ,
current_pid
);
activity_string = 'Nova consulta registrada '||
' database_id = '|| log_database_id ||
' query_md5hash='||log_md5hash||
' , timepoint = '||to_char(log_timepoint,'YYYYMMDD HH24:MI:SS');
PERFORM pg_log( log_database_id , 'log_query' , activity_string);
EXCEPTION
WHEN unique_violation THEN
activity_string = 'EXCEÇÃO *** consulta já registrada '||
' database_id = '|| log_database_id ||
' query_md5hash='||log_md5hash||n ' , timepoint = '||to_char(log_timepoint,'YYYYMMDD HH24:MI:SS');
PERFORM pg_log( log_database_id , 'log_query' , activity_string);
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
RETURN result;
END IF;
------------------------------------------------
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;
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 = ' queryid atualizado = '||pg_stat_history_rec.queryid||
' para log_query com id = '||log_query_rec.id;
EXIT ;
END IF ;
END LOOP ;
RETURN result ;
END
$$ LANGUAGE plpgsql;Como resultado, a tabela contém o texto de consulta atual, os planos de execução, o valor hash do plano de execução e o valor hash do texto da consulta.
Preencher o valor queryid na tabela history_pg_stat_activity
update_history_pg_stat_activity_by_queryid.sql
--update_history_pg_stat_activity_by_queryid.sql
CREATE OR REPLACE FUNCTION update_history_pg_stat_activity_by_queryid() RETURNS boolean AS $$
DECLARE
result boolean ;
history_pg_stat_activity_rec record ;
pg_stat_query text ;
pg_stat_query_text text ;
pg_stat_history_rec record;
found_flag boolean;
history_pg_stat_activity_query text ;
query_text text ;
activity_string text ;
BEGIN
RAISE NOTICE '***update_history_pg_stat_activity_by_queryid';
result = TRUE ;
FOR history_pg_stat_activity_rec IN
SELECT DISTINCT(query) AS query
FROM activity_hist.history_pg_stat_activity
WHERE queryid IS NULL
LOOP
history_pg_stat_activity_query = regexp_replace(history_pg_stat_activity_rec.query,'n+',' ','g');
history_pg_stat_activity_query = regexp_replace(history_pg_stat_activity_query,'t+',' ','g');
history_pg_stat_activity_query = regexp_replace(history_pg_stat_activity_query,' +',' ','g');
history_pg_stat_activity_query = regexp_replace(history_pg_stat_activity_query,';','','g');
query_text = trim(trailing ' ' from history_pg_stat_activity_query);
FOR pg_stat_history_rec IN
SELECT
queryid ,
query
FROM
--pg_stat_history
pg_stat_db_queries
WHERE
queryid is not null
GROUP BY queryid , query
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');
pg_stat_query_text = pg_stat_query;
IF (query_text LIKE pg_stat_query_text) THEN
found_flag = TRUE ;
ELSE
found_flag = FALSE ;
END IF;
IF found_flag
THEN
UPDATE activity_hist.history_pg_stat_activity
SET queryid = pg_stat_history_rec.queryid
WHERE regexp_replace(regexp_replace(regexp_replace(regexp_replace(query,'n+',' ','g'),'t+',' ','g'),' +',' ','g'),';','','g')
LIKE query_text||'%' ;
activity_string = 'history_pg_stat_activity foi atualizado por queryid = '||pg_stat_history_rec.queryid;
RAISE NOTICE '%',activity_string;
PERFORM pg_log( 999 , 'update_history_pg_stat_activity_by_queryid' , activity_string);
EXIT ;
END IF ;
END LOOP ;
IF NOT found_flag
THEN
activity_string = 'AVISO : Não ENCONTRADO queryid para a consulta : '||query_text ;
RAISE NOTICE '%',activity_string;
PERFORM pg_log( 999 , 'update_history_pg_stat_activity_by_queryid' , activity_string);
END IF ;
RAISE NOTICE 'ATUALIZAR log_query se a consulta não estiver registrada no log-file';
END LOOP;
RETURN result ;
END
$$ LANGUAGE plpgsql;Como resultado, a tabela contém o valor queryid correspondente ao valor queryid da consulta.
Resultado
Vinculando pg_stat_activity, pg_stat_statements, log_query, é possível obter muitas informações úteis sobre a consulta, em particular:
- Histórico dos planos de execução.
- Histórico do tempo de CPU da consulta.
- Histórico das esperas da consulta.
Os dados e muitos relatórios adicionais serão descritos no próximo artigo.
Desenvolvimento
Ao correlacionar as informações disponíveis com o histórico da representação pg_locks, é possível obter informações sobre qual bloqueio específico a consulta estava aguardando e, o mais importante, qual processo (consulta) detinha esse bloqueio.
A solução para esta tarefa será descrita no próximo artigo. Atualmente, está em fase de testes e aprimoramentos.
Fonte: habr.com
