oracle pmon 多长时间,oracle 11g pmon工作内容系列一

背景

熟悉PMON的含义及工作内容。

结论

1,pmon可以用10246 event进行跟踪PMON工作过程

2,pmon工作内容如下：

后经查询官方手册发现，PMON的工作内容如下：

1，监控后台进程运行状况

2，如果某些进程异常中断，PMON去释放会话资源以及占用的锁LOCK

3，更新事务表的标志以及清除事务XID的标记

4，清除异常中断会话在BUFFER CACHE占用的缓存

5，PMON也负责定期把数据库实例注册到监听器中

3，10246 EVENT产生的TRACE FILE分析摘录

--PMON接到通知

PMON posted from location=FILE:/ade/b/1640894963/oracle/rdbms/src/hdir/ksl2.h LINE:2160 ID:kslges, process=6c, post_num=5

*** 2015-11-01 21:49:30.646

PMON posted from location=FILE:/ade/b/1640894963/oracle/rdbms/src/hdir/ksl2.h LINE:2160 ID:kslges, process=39, post_num=6

PMON posted from location=FILE:/ade/b/1640894963/oracle/rdbms/src/hdir/ksu.h LINE:12751 ID:ksupsc, process=b8, post_num=7

*** 2015-11-01 22:03:02.812

deleting session 0xdc97f1b0 sid=201 serial=188 --PMON发现上述测试会话被人为KILL

*** 2015-11-01 22:03:03.382

deletion of killed session 0xdc97f1b0 successful

--这里就是ORACLE内核代码负责清理被KILL会话占用的资源

PMON posted from location=FILE:/ade/b/1640894963/oracle/rdbms/src/hdir/ksu.h LINE:12737 ID:ksuabt, process=0, post_num=8

PMON posted from location=FILE:/ade/b/1640894963/oracle/rdbms/src/hdir/ksu.h LINE:12763 ID:ksuxfd, process=2, post_num=9

PMON posted from location=FILE:/ade/b/1640894963/oracle/rdbms/src/hdir/ksu.h LINE:12763 ID:ksuxfd, process=2, post_num=10

PMON posted from location=FILE:/ade/b/1640894963/oracle/rdbms/src/hdir/ksu.h LINE:12763 ID:ksuxfd, process=2, post_num=11

PMON posted from location=FILE:/ade/b/1640894963/oracle/rdbms/src/hdir/ksu.h LINE:12763 ID:ksuxfd, process=2, post_num=12

PMON posted from location=FILE:/ade/b/1640894963/oracle/rdbms/src/hdir/ksu.h LINE:12763 ID:ksuxfd, process=2, post_num=13

PMON posted from location=FILE:/ade/b/1640894963/oracle/rdbms/src/hdir/ksu.h LINE:12763 ID:ksuxfd, process=2, post_num=14

PMON posted from location=FILE:/ade/b/1640894963/oracle/rdbms/src/hdir/ksu.h LINE:12763 ID:ksuxfd, process=2, post_num=15

PMON posted from location=FILE:/ade/b/1640894963/oracle/rdbms/src/hdir/ksu.h LINE:12763 ID:ksuxfd, process=2, post_num=16

PMON posted from location=FILE:/ade/b/1640894963/oracle/rdbms/src/hdir/ksu.h LINE:12763 ID:ksuxfd, process=2, post_num=17

PMON posted from location=FILE:/ade/b/1640894963/oracle/rdbms/src/hdir/ksu.h LINE:12763 ID:ksuxfd, process=2, post_num=18

PMON posted from location=FILE:/ade/b/1640894963/oracle/rdbms/src/hdir/ksu.h LINE:12763 ID:ksuxfd, process=2, post_num=19

PMON posted from location=FILE:/ade/b/1640894963/oracle/rdbms/src/hdir/ksu.h LINE:12763 ID:ksuxfd, process=2, post_num=20

PMON posted from location=FILE:/ade/b/1640894963/oracle/rdbms/src/hdir/ksu.h LINE:12763 ID:ksuxfd, process=2, post_num=21

PMON posted from location=FILE:/ade/b/1640894963/oracle/rdbms/src/hdir/ksu.h LINE:12763 ID:ksuxfd, process=2, post_num=22

PMON posted from location=FILE:/ade/b/1640894963/oracle/rdbms/src/hdir/ksu.h LINE:12763 ID:ksuxfd, process=2, post_num=23

PMON posted from location=FILE:/ade/b/1640894963/oracle/rdbms/src/hdir/ksu.h LINE:12763 ID:ksuxfd, process=2, post_num=24

PMON posted from location=FILE:/ade/b/1640894963/oracle/rdbms/src/hdir/ksu.h LINE:12763 ID:ksuxfd, process=2, post_num=25

PMON posted from location=FILE:/ade/b/1640894963/oracle/rdbms/src/hdir/ksu.h LINE:12763 ID:ksuxfd, process=2, post_num=26

PMON ignoring post from location=FILE:/ade/b/1640894963/oracle/rdbms/src/hdir/ksu.h LINE:12763 ID:ksuxfd, process=2

*** 2015-11-01 22:03:06.428

marked process 0xdd6589c0 pid=184 serial=2 ospid = 11635 dead --PMON清理完被KILL后，标记为DEAD

*** 2015-11-01 22:03:06.446

deleting process 0xdd6589c0 pid=184 serial=2 priority=0 --然后删除这个会话对应的操作系统进程资源

deletion of process dd6589c0 pid=184 seq=2 successful

测试

1,数据库版本

SQL> select * from v$version where rownum=1;

BANNER

--------------------------------------------------------------------------------

Oracle Database 11g Enterprise Edition Release 11.2.0.1.0 - 64bit Production

2，跟踪pmon

SQL> alter session set tracefile_identifier='pmon_test1';

Session altered.

SQL> alter system set events='10246 trace name context forever,level 1';

System altered.

3,用户测试会话

SQL> select sid from v$mystat where rownum=1;

SID

----------

201

SQL> select sid,serial# from v$session where sid=201;

SID SERIAL#

---------- ----------

201 188

SQL> create table t_pmon(a int,b int);

Table created.

SQL> insert into t_pmon select level,level from dual connect by level<=1000000;

insert into t_pmon select level,level from dual connect by level<=1000000

ERROR at line 1:

ORA-00028: your session has been killed

--另启会话杀掉正在插入记录的上述测试会话

SQL> alter system kill session '201,188';

System altered.

3,关闭pmon跟踪

SQL> alter system set events='10246 trace name context off';

System altered.

4,查看pmon的TRACE FILE