Streams AQ: qmn coordinator waiting for slave to start, streamsqmn

Streams AQ: qmn coordinator waiting for slave to start, streamsqmn

This wait event is reported in the Top 5 Timed events of Node2 with a set of 10g RAC (10.2.0.5) today.

Top 5 Timed Events

Event	Waits	Time (s)	Avg Wait (MS)	% Total Call Time	Wait Class
CPU time		78		123.5
Streams AQ: qmn coordinator waiting for slave to start	1	6	6,326	10.0	Other
Gc cr block 2-way	11,434	3	0	4.3	Cluster
Control file sequential read	5,090	2	0	2.8	System I/O
Db file sequential read	238	1	4	1.5	User I/O

According to the actual situation, NOde2 is mainly used for WEB queries and is the owner of the DMS master. The Stream function is not deployed, which is a bit strange.

Analysis Method:

1. check the parameter AQ_TM_PROCESSES related to Stream and find that the value is 0. According to the 10g official documentation, AQ_TM_PROCESSES = 0 and the qmn monitoring process is not started, it can be started only when it is SET to 1 to 10, that is, alter system set AQ_TM_PROCESSES = 1. You can SET it according to the actual situation.

2. As the online master said, "The database load is very low." We have a very low Node2.

Note:

The default value and maximum setting range of this parameter are different for 10g and 11g.

The default value of 10g is 0, the range is 1-10, the default value of 11g is 1, and the range is 1-40.

Spam:

The 10g Official documentation really requires the Search function to find the parameter definitions. The 11g clearly put the initialization parameter file in a document.

 

Q: What is KSV master wait? What did he do? detailed points, high scores?

That is, the so-called latency MasterCard server/
This is a credit consumption system, like a POS machine used in China. When you swipe your card for consumption, the consumption is sent to the server. No money can be deducted. The reservation will be successfully transferred tomorrow. For example, it will be delayed, and a manual operation is required to complete the transfer.