DB2服务器CPU使用率高，可以通过以下方式去分析。DB2 V9.5版本以前是多进程，想看哪个进程占用CPU和内存高分别使用ps aux --sort=-%cpu和ps aux --sort=-rss，V9.5版本以后是单进程多线程。
查看db2sysc进程的PID
[db2inst1]# ps -ef | grep db2sysc
查看db2sysc多线程
AIX：ps -emo THREAD -p <PID>
Linux：ps -lLfp <PID>
看下DB2 V9.5版本之前与之后多进程与多线程的区别（以主进程db2sysc为例）
DB2 V9.1：
[inst91]# ps -ef | grep db2sysc
inst91 21741 21740 0 12:48 pts/1 00:00:00 db2sysc 0
[inst91]# ps -lLfp 21741
F S UID PID PPID LWP C NLWP PRI NI ADDR SZ WCHAN STIME TTY TIME CMD
4 S inst91 21741 21740 21741 0 1 78 0 - 85875 msgrcv 12:48 pts/1 00:00:00 db2sysc 0DB2 V10.5：
[inst105]# ps -ef | grep db2sysc
inst105 5797 5795 0 Jan21 ? 00:01:02 db2sysc 0
[inst105]# ps -lLfp 5797
F S UID PID PPID LWP C NLWP PRI NI ADDR SZ WCHAN STIME TTY TIME CMD
4 S inst105 5797 5795 5797 0 11 80 0 - 276364 184466 Jan21 ? 00:00:00 db2sysc 0
1 S inst105 5797 5795 5798 0 11 78 0 - 276364 msgrcv Jan21 ? 00:00:11 db2sysc 0
1 S inst105 5797 5795 5799 0 11 75 0 - 276364 - Jan21 ? 00:00:08 db2sysc 0
1 S inst105 5797 5795 5800 0 11 75 0 - 276364 semtim Jan21 ? 00:00:00 db2sysc 0
1 S inst105 5797 5795 5801 0 11 78 0 - 276364 - Jan21 ? 00:00:00 db2sysc 0
1 S inst105 5797 5795 5802 0 11 58 - - 276364 - Jan21 ? 00:00:00 db2sysc 0
1 S inst105 5797 5795 5806 0 11 58 - - 276364 - Jan21 ? 00:00:00 db2sysc 0
1 S inst105 5797 5795 5808 0 11 75 0 - 276364 msgrcv Jan21 ? 00:00:00 db2sysc 0
1 S inst105 5797 5795 5809 0 11 78 0 - 276364 - Jan21 ? 00:00:13 db2sysc 0
1 S inst105 5797 5795 27824 0 11 75 0 - 276364 - Jan21 ? 00:00:00 db2sysc 0
1 S inst105 5797 5795 25718 0 11 75 0 - 276364 semtim Jan21 ? 00:00:01 db2sysc 0
以DB2 V10.5为例，V9.5之后db2pd才有edu参数，查看EDU（默认以CPU排序）
[inst105]# db2pd -edu
Database Member 0 -- Active -- Up 1 days 16:47:30 -- Date 2022-01-22-13.42.39.849120
List of all EDUs for database member 0
db2sysc PID: 5797
db2wdog PID: 5795
db2acd PID: 5811
EDU ID TID Kernel TID EDU Name USR (s) SYS (s)
========================================================================================================================================
234 47175950133568 25718 db2agent (idle) 0 0.470000 1.230000
170 47175883024704 27824 db2agent (idle) 0 0.130000 0.300000
17 47175992076608 5809 db2resync 0 0.430000 13.140000
16 47175996270912 5808 db2ipccm 0 0.040000 0.440000
15 47176000465216 5806 db2wlmtm 0 0.340000 0.160000
14 47176004659520 5802 db2wlmt 0 0.170000 0.050000
13 47176008853824 5801 db2licc 0 0.000000 0.000000
12 47176013048128 5800 db2thcln 0 0.000000 0.020000
11 47176017242432 5799 db2alarm 0 2.310000 6.240000
1 47175757195584 5798 db2sysc 0 2.420000 8.950000
根据EDUID找出对应的ApplHandl ID
[inst105]# db2pd -d dbname -app
查看对应ApplHand ID的快照信息
db2 get snapshot for application agentid <applHandl ID>
根据实际情况是否force掉正在执行的事务
db2 "force application(agentid)"
查看消耗CPU高的SQL
ORDER BY USER CPU
select
NUM_EXECUTIONS,
TOTAL_USR_CPU_TIME,
dec(double(TOTAL_USR_CPU_TIME)/double(case when NUM_EXECUTIONS=0 then 1 else NUM_EXECUTIONS end),20,2) as AVG_USR_CPU_TIME,
TOTAL_USR_CPU_TIME_MS,
dec(double(TOTAL_USR_CPU_TIME_MS)/double(case when NUM_EXECUTIONS=0 then 1 else NUM_EXECUTIONS end),20,2) as AVG_USR_CPU_TIME_MS,
TOTAL_SYS_CPU_TIME,
TOTAL_SYS_CPU_TIME_MS,
TOTAL_EXEC_TIME,
TOTAL_EXEC_TIME_MS,
ROWS_READ,
ROWS_WRITTEN,
STMT_SORTS,
SORT_OVERFLOWS,
TOTAL_SORT_TIME,
STMT_TEXT
from SYSIBMADM.SNAPDYN_SQL order by TOTAL_USR_CPU_TIME desc,TOTAL_USR_CPU_TIME_MS desc fetch first 30 rows only with ur
ORDER BY SYS USER
select
NUM_EXECUTIONS,
TOTAL_USR_CPU_TIME,
TOTAL_USR_CPU_TIME_MS,
TOTAL_SYS_CPU_TIME,
TOTAL_SYS_CPU_TIME_MS,
TOTAL_EXEC_TIME,
TOTAL_EXEC_TIME_MS,
ROWS_READ,
ROWS_WRITTEN,
STMT_SORTS,
SORT_OVERFLOWS,
TOTAL_SORT_TIME,
STMT_TEXT
from SYSIBMADM.SNAPDYN_SQL order by TOTAL_SYS_CPU_TIME desc,TOTAL_SYS_CPU_TIME_MS desc fetch first 30 rows only with ur
