Oracle体系结构及备份（十三）bg-pmon
一 什么是PMON进程 The process monitor performs processrecovery when a user process fails. PMON is responsible for cleaning up thecache and freeing resources that the process was using. PMON also checks on thedispatcher processes (described
一 什么是PMON进程
The process monitor performs processrecovery when a user process fails. PMON is responsible for cleaning up thecache and freeing resources that the process was using. PMON also checks on thedispatcher processes (described later in this table) and server processes andrestarts them if they have failed.
PMON，进程监控进程（动态注册监听器）
作用：
清除失败的进程
回滚事务
释放锁
释放其他资源
重启死掉的Dispatchers
二 操作示例
oracle@localhost 桌面]$ ps -ef | grep ora_ | grep pmon oracle 2889 1 0 17:01 ? 00:00:00 ora_pmon_orcl [oracle@localhost 桌面]$ kill -9 2889 [oracle@localhost 桌面]$ ps -ef | grep ora_ | grep pmon [oracle@localhost 桌面]$ ps -ef | grep ora_ oracle 2950 2597 0 17:05 pts/0 00:00:00 grep ora_ [oracle@localhost 桌面]$ ps -ef | grep ora_ | grep pmon [oracle@localhost 桌面]$ sqlplus / as sysdba; SQL*Plus: Release 10.2.0.1.0 - Production on Tue Jun 4 17:05:59 2013 Copyright (c) 1982, 2005, Oracle. All rights reserved. Connected to an idle instance. SQL> conn scott/tiger; ERROR: ORA-01034: ORACLE not available ORA-27101: shared memory realm does not exist Linux Error: 2: No such file or directory Warning: You are no longer connected to ORACLE. SQL> conn / as sysdba; Connected to an idle instance. SQL> exit; Disconnected [oracle@localhost 桌面]$ ps -ef | grep ora_ oracle 2963 2597 0 17:06 pts/0 00:00:00 grep ora_ [oracle@localhost 桌面]$ startup bash: startup: command not found [oracle@localhost 桌面]$ sqlplus / as sysdba; SQL*Plus: Release 10.2.0.1.0 - Production on Tue Jun 4 17:07:01 2013 Copyright (c) 1982, 2005, Oracle. All rights reserved. Connected to an idle instance. SQL> startup ORACLE instance started. Total System Global Area 838860800 bytes Fixed Size 1222192 bytes Variable Size 775948752 bytes Database Buffers 58720256 bytes Redo Buffers 2969600 bytes Database mounted. Database opened. SQL> conn scott/tiger; Connected. SQL> exit; Disconnected from Oracle Database 10g Enterprise Edition Release 10.2.0.1.0 - Production With the Partitioning, OLAP and Data Mining options [oracle@localhost 桌面]$ ps -ef | grep ora_ oracle 2968 1 0 17:07 ? 00:00:00 ora_pmon_orcl oracle 2970 1 0 17:07 ? 00:00:00 ora_psp0_orcl oracle 2972 1 0 17:07 ? 00:00:00 ora_mman_orcl oracle 2974 1 0 17:07 ? 00:00:00 ora_dbw0_orcl oracle 2976 1 0 17:07 ? 00:00:00 ora_lgwr_orcl oracle 2978 1 0 17:07 ? 00:00:00 ora_ckpt_orcl oracle 2980 1 0 17:07 ? 00:00:00 ora_smon_orcl oracle 2982 1 0 17:07 ? 00:00:00 ora_reco_orcl oracle 2984 1 0 17:07 ? 00:00:00 ora_cjq0_orcl oracle 2986 1 1 17:07 ? 00:00:00 ora_mmon_orcl oracle 2988 1 0 17:07 ? 00:00:00 ora_mmnl_orcl oracle 2990 1 0 17:07 ? 00:00:00 ora_d000_orcl oracle 2992 1 0 17:07 ? 00:00:00 ora_s000_orcl oracle 2996 1 0 17:07 ? 00:00:00 ora_qmnc_orcl oracle 2998 1 2 17:07 ? 00:00:00 ora_j000_orcl oracle 3004 1 0 17:07 ? 00:00:00 ora_q000_orcl oracle 3006 1 0 17:07 ? 00:00:00 ora_q001_orcl oracle 3009 2597 0 17:07 pts/0 00:00:00 grep ora_ [oracle@localhost 桌面]$ ps -ef | grep ora_ | grep pmon oracle 2968 1 0 17:07 ? 00:00:00 ora_pmon_orcl
三 总结
1. PMON，进程监控进程，动态注册监听器。
2.作用：清除失败的进程、回滚事务、释放锁、释放其他资源、重启死掉的Dispatchers。
3.Linux下仍然采用ps命令查看。
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