Mmon Process Manual Start

Manual Start Mmon Process

1. Failure Phenomena

# Some hot guy gets business people to reflect system slowness,RAC Environment

# Generate AWR Report found node 1 no data

# Query Snapshot view, found that only node 1 does not have snapshot records , node 2 has a normal snapshot record

SYS > select Instance_number,count (*) from Dba_hist_snapshot GROUP by Instance_number;

#思考: If two nodes do not have a snapshot, the direction of consideration may be the cause: the snapshot is off

"#查询视图

SYS > select * from Dba_hist_wr_control;

DBID Snap_interval RETENTION Topnsql
---------- -------------------- -------------------- ----------
754170409 +40150 00:00:00.0 +00008 00:00:00.0 DEFAULT

#关闭awr快照命令

SYS > Begin dbms_workload_repository. Modify_snapshot_settings (11520,0); End

#调整快照间隔30分钟及保留5天

EXEC dbms_workload_repository.modify_snapshot_settings (interval=>30,retention=>5*24*60); 】

# by querying the mmon process, it is found that on the system of node one, there is no mmon process Service, so judging, because the mmon process does not start properly , causing the AWR snapshot to fail to generate, missing snapshot information

Ps-ef|grep Mmon |grep-v grep

2. What is the mmon process

managing the monitoring process mmon| | MMOL

Mmon The view information to the snapshot via the AWR interval time

Mmil fill in the buffer with ASH , written to disk, via AWR interval Time

3. Simulation mmon process missing

[Email protected] ~]# ps-ef|grep Mmon |grep-v grep

Oracle 16947 1 0 Apr13? 00:00:08 Ora_mmon_enmo

#KILL Mmon Process

[Email protected] ~]# kill-9 16947

[Email protected] ~]# ps-ef|grep Mmon |grep-v grep

# Create a snapshot manually

SYS > Begin

Dbms_workload_repository.create_snapshot ();

End

/

PL/SQL procedure successfully completed.

# Query the process again

[[email protected] ~]# ps-ef|grep Mmon |grep-v grep-- not started

4. manually start the Mmon process

SYS > ALTER system enable restricted session;

[Email protected] ~]# ps-ef|grep Mmon |grep-v grep

Oracle 21960 1 0 20:18? 00:00:00 Ora_mmon_enmo

SYS > Alter system disable restricted session;

[Email protected] ~]# ps-ef|grep Mmon |grep-v grep

Oracle 21960 1 0 20:18? 00:00:00 Ora_mmon_enmo

# If you can restart the database, restart the cluster, restart the system can be implemented, but the operation is minimal, perform the above operation

Mmon Process Manual Start