oracle 10g慢慢退出了,但用的地方也还有。这里再记一下案例:
数据库16:58出现大量4031,导致数据库无法使用,取对应时段的AWR@H_301_2@
发现shared_pool一直在收缩;
查看日志:
** 2018-07-26 16:58:09.868
ORA-00604: 递归 sql 级别 1 出现错误
ORA-04031: 无法分配 32 字节的共享内存 ("shared pool","select count() from sys.job...","sql area","tmp")@H_301_2@
查看对应的trc:@H_301_2@
LIBRARY CACHE STATISTICS: namespace gets hit ratio pins hit ratio reloads invalids -------------- --------- --------- --------- --------- ---------- ---------- CRSR 889957320 0.245 2974322326 0.877 6674225 3570108
出现大量的cursor无法共享;
并伴随出现:@H_301_2@
last wait for 'SGA: allocation forcing component growth' blocking sess=0x0000000000000000 seq=62360 wait_time=7064 seconds since wait started=0 =0,=0,=0 Dumping Session Wait History for 'SGA: allocation forcing component growth' count=1 wait_time=7064 =0,=0
现察subpool:@H_301_2@
Memory Utilization of Subpool 2 Allocation Name Size _________________________ __________ "free memory " -2020262480
由于系统已重启,只能检查现在的resize情况:@H_301_2@
set linesize 1000; SELECT start_time,component,oper_type,oper_mode,initial_size/1048576 "INITIAL MB",final_size/1048576 "FINAL MB",end_time FROM v$sga_resize_ops WHERE component IN ( 'DEFAULT buffer cache','shared pool' ) AND status = 'COMPLETE' ORDER BY start_time,component;
发现调整还是很频繁;@H_301_2@
检查历史的sga分配情况:发现故障时段大量的内存分配了kgh:no accessselect * from DBA_HIST_SGASTAT where name in ('buffer_cache','sql area','KGH: NO ACCESS') and snap_id>40630
@H_301_2@
解决办法:
1 打补丁
Patch 7189722: APPSST GSI 10G : VERY FREQUENT GROW/SHRINK SGA RESIZE OPERATION HAPPENING
2 禁用ASMM功能;
参见MOS:
How To Prevent The Growth Of The Component 'KGH: NO ACCESS' In The Shared Pool When ASMM Is Enabled (Doc ID 451960.1)
Common Cause for ORA-4031 in 10gR2,Excess "KGH: NO ACCESS" Memory Allocation [Video] (Doc ID 801787.1)
3 依旧启用ASMM,但设置buffer cache/shared pool的最小值.@H_301_2@
4 调整_memory_broker_stat_interval的值,减少sga 的auto resize频率;@H_301_2@ 原文链接:https://www.f2er.com/oracle/205755.html