数据库服务器不正常的跑高
当前session等待cursor: mutex S，SQL是
SQL ID:az33m61ym46y4
SELECT NULL AS table_cat,
o.owner AS table_schem,
o.object_name AS table_name,
o.object_type AS table_type,
NULL AS remarks
FROM all_objects o
WHERE o.owner LIKE :1 ESCAPE '/'
AND o.object_name LIKE :2 ESCAPE '/'
AND o.object_type IN ('xxx', 'TABLE')
ORDER BY table_type, table_schem, table_name
对这些会话进行trace
WAIT #1: nam='cursor: mutex S' ela= 36 idn=0 value=6549825126405 where=4993644290 obj#=-1 tim=1550147900582216 WAIT #1: nam='cursor: mutex S' ela= 154 idn=0 value=8220567404550 where=4993644307 obj#=-1 tim=1550147900582874 WAIT #1: nam='cursor: mutex S' ela= 196 idn=0 value=7133940678660 where=4993644351 obj#=-1 tim=1550147900583996 WAIT #1: nam='cursor: mutex S' ela= 53 idn=0 value=10900626997258 where=4993644426 obj#=-1 tim=1550147900585612 WAIT #1: nam='cursor: mutex S' ela= 167 idn=0 value=2272037699589 where=4993644467 obj#=-1 tim=1550147900586830 WAIT #1: nam='cursor: mutex S' ela= 158 idn=0 value=10900626997252 where=4993644635 obj#=-1 tim=1550147900590761 WAIT #1: nam='cursor: mutex S' ela= 91 idn=0 value=9216999817220 where=4993644677 obj#=-1 tim=1550147900591656 WAIT #1: nam='cursor: mutex S' ela= 24 idn=0 value=7142530613252 where=4993644728 obj#=-1 tim=1550147900592860 WAIT #1: nam='cursor: mutex S' ela= 63 idn=0 value=2808908611588 where=4993644884 obj#=-1 tim=1550147900597255 WAIT #1: nam='cursor: mutex S' ela= 24 idn=0 value=10900626997255 where=4993644898 obj#=-1 tim=1550147900597579 WAIT #1: nam='cursor: mutex S' ela= 16 idn=0 value=7133940678660 where=4993644910 obj#=-1 tim=1550147900597916 WAIT #1: nam='cursor: mutex S' ela= 192 idn=0 value=5510443040772 where=4993645004 obj#=-1 tim=1550147900600663
AWR和ASH报告中
该SQL是HTTP服务上的一个测试数据库连接功能，需要开发配合改写。
MOS文档上可以用 flush shared_pool缓解，经测试，无效
怀疑和buffer cache 有关系，一个大胆的想法不知道当讲不当讲：flush buffer_cache
执行后，实例崩溃
ALTER SYSTEM: Flushing buffer cache Errors in file /u01/app/oracle/diag/rdbms/ahdb1/ahdb1/trace/ahdb1_ckpt_38170.trc (incident=256146): ORA-00600: internal error code, arguments: [kcbo_unlink_q_bg_3], [0xCE4DBE200], [1], [1], [0], [0], [0], [0], [], [], [], [] Incident details in: /u01/app/oracle/diag/rdbms/ahdb1/ahdb1/incident/incdir_256146/ahdb1_ckpt_38170_i256146.trc Errors in file /u01/app/oracle/diag/rdbms/ahdb1/ahdb1/trace/ahdb1_ckpt_38170.trc: ORA-00600: internal error code, arguments: [kcbo_unlink_q_bg_3], [0xCE4DBE200], [1], [1], [0], [0], [0], [0], [], [], [], [] CKPT (ospid: 38170): terminating the instance due to error 469 Instance terminated by CKPT, pid = 38170
再次启动实例后，CPU回到正常，数据库等待回到正常。