在做苍穹性能测试或者分析数据库问题的时候可以采用以下一些内容作为衡量数据库性能的指标。

指标分类	指标项	值	获取值方法
主机	数据库机器cpu使用率	<80%	top,sar 命令
	数据库机器负载	<cpu核数*0.7	top,uptime 命令
	数据库机器磁盘IO使用率	<80%	iostat命令
	数据库机器内存使用率	<90%	top,free命令,/proc/meminfo
	数据库机器磁盘空间	使用率<90%	df
	数据库机器网卡流量	<100%	iftop,sar
	网络延迟	<0.5ms	ping，hping3
数据库	表大小	核心单表<10G	select table_catalog, tablename, pg_size_pretty(tablesize) as table_size from ( select table_catalog, ( table_schema\|\|'.'\|\| table_name ) as tablename, pg_table_size( table_schema\|\|'.'\|\| table_name ) as tablesize from information_schema.tables where pg_table_size( table_schema\|\|'.'\|\| table_name ) > 10737418240 order by pg_table_size(table_schema\|\|'.'\|\| table_name ) desc ) as all_tables ;
	最大连接数	<=5000	select count(1) from pg_stat_activity;
	活跃连接数	<=1000	select count(1) from pg_stat_activity where state ='active';
	实时慢SQL	不能有大量>60s	查看后台慢日志记录
	错误日志	不能出现有error的日志	查看数据库pg_log错误日志
	wal日志	产生wal日志<1min	查看pg_wal目录的wal日志生成情况
	阻塞事务	不能出现大量阻塞SQL	with t_wait as ( select a.mode,a.locktype,a.database,a.relation,a.page,a.tuple,a.classid,a.granted, a.objid,a.objsubid,a.pid,a.virtualtransaction,a.virtualxid,a.transactionid,a.fastpath, b.state,b.query,b.xact_start,b.query_start,b.usename,b.datname,b.client_addr,b.client_port,b.application_name from pg_locks a,pg_stat_activity b where a.pid=b.pid and not a.granted ), t_run as ( select a.mode,a.locktype,a.database,a.relation,a.page,a.tuple,a.classid,a.granted, a.objid,a.objsubid,a.pid,a.virtualtransaction,a.virtualxid,a.transactionid,a.fastpath, b.state,b.query,b.xact_start,b.query_start,b.usename,b.datname,b.client_addr,b.client_port,b.application_name from pg_locks a,pg_stat_activity b where a.pid=b.pid and a.granted ), t_overlap as ( select r.* from t_wait w join t_run r on ( r.locktype is not distinct from w.locktype and r.database is not distinct from w.database and r.relation is not distinct from w.relation and r.page is not distinct from w.page and r.tuple is not distinct from w.tuple and r.virtualxid is not distinct from w.virtualxid and r.transactionid is not distinct from w.transactionid and r.classid is not distinct from w.classid and r.objid is not distinct from w.objid and r.objsubid is not distinct from w.objsubid and r.pid <> w.pid ) ), t_unionall as ( select r.* from t_overlap r union all select w.* from t_wait w ) select locktype,datname,relation::regclass,page,tuple,virtualxid,transactionid::text,classid::regclass,objid,objsubid, string_agg( 'Pid: '\|\|case when pid is null then 'NULL' else pid::text end\|\|chr(10)\|\| 'Lock_Granted: '\|\|case when granted is null then 'NULL' else granted::text end\|\|' , Mode: '\|\|case when mode is null then 'NULL' else mode::text end\|\|' , FastPath: '\|\|case when fastpath is null then 'NULL' else fastpath::text end\|\|' , VirtualTransaction: '\|\|case when virtualtransaction is null then 'NULL' else virtualtransaction::text end\|\|' , Session_State: '\|\|case when state is null then 'NULL' else state::text end\|\|chr(10)\|\| 'Username: '\|\|case when usename is null then 'NULL' else usename::text end\|\|' , Database: '\|\|case when datname is null then 'NULL' else datname::text end\|\|' , Client_Addr: '\|\|case when client_addr is null then 'NULL' else client_addr::text end\|\|' , Client_Port: '\|\|case when client_port is null then 'NULL' else client_port::text end\|\|' , Application_Name: '\|\|case when application_name is null then 'NULL' else application_name::text end\|\|chr(10)\|\| 'Xact_Start: '\|\|case when xact_start is null then 'NULL' else xact_start::text end\|\|' , Query_Start: '\|\|case when query_start is null then 'NULL' else query_start::text end\|\|' , Xact_Elapse: '\|\|case when (now()-xact_start) is null then 'NULL' else (now()-xact_start)::text end\|\|' , Query_Elapse: '\|\|case when (now()-query_start) is null then 'NULL' else (now()-query_start)::text end\|\|chr(10)\|\| 'SQL (Current SQL in Transaction): '\|\|chr(10)\|\| case when query is null then 'NULL' else query::text end, chr(10)\|\|'--------'\|\|chr(10) order by ( case mode when 'INVALID' then 0 when 'AccessShareLock' then 1 when 'RowShareLock' then 2 when 'RowExclusiveLock' then 3 when 'ShareUpdateExclusiveLock' then 4 when 'ShareLock' then 5 when 'ShareRowExclusiveLock' then 6 when 'ExclusiveLock' then 7 when 'AccessExclusiveLock' then 8 else 0 end ) desc, (case when granted then 0 else 1 end) ) as lock_conflict from t_unionall group by locktype,datname,relation,page,tuple,virtualxid,transactionid::text,classid,objid,objsubid ;











	未提交事务	不能出现大量没有提交的事务	select count(1) from pg_stat_activity where state ='idle in transaction';









	死锁	不能出现大量死锁	查看日志文件
	死锁	不能出现大量死锁	查看日志文件
	QPS	单机实例QPS<1w	一般情况QPS不能出现大的波动 with a as (select sum(calls) s from pg_stat_statements), b as (select sum(calls) s from pg_stat_statements , pg_sleep(1)) select b.s-a.s qps from a,b;
	TPS	<QPS*0.5	create or replace procedure dba.tps() as $$ declare v1 int8; v2 int8; begin select txid_snapshot_xmax(txid_current_snapshot()) into v1; commit; perform pg_sleep(1); select txid_snapshot_xmax(txid_current_snapshot()) into v2; commit; raise notice 'tps: %', v2-v1; end; $$ language plpgsql ;


	主从延迟	主从延迟<5min	pg_autoctl show state/select application_name,client_addr,client_hostname,client_port,state,sync_priority,sync_state,pg_size_pretty(pg_wal_lsn_diff(pg_current_wal_lsn(), replay_lag)) from pg_stat_replication;

苍穹性能测试-- PostgreSQL性能指标

苍穹性能测试-- PostgreSQL性能指标

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