High rejected operation in SM12

[Former Member]

Hi, all.

We are having some performance issue with certain custom programs. The system is ERP 6.0 EHP5. Looking at the SM12 stats, I noticed really high reject ratio. However, I haven't found any potential solution for it. Can you please advise what we can do in the situation? The lock table is set to 200000 and I don't see we are anywhere close to lock table overflow.

Thx

Jonathan.

[isaias_freitas · Accepted solution]

Hello Jonathan,

The application causing the high number of rejections has to be fixed.

These rejections mean that a report tried to lock an object that was already locked by a different session. This is application logic. The application has to deal with this (e.g., verify whether the object is already locked before trying to lock it; if it could not lock it, wait for some time before trying to lock it again instead of using an infinite loop without any pause; ...).

Regards,

Isaías

[Former Member · Accepted solution]

Hi, Isaias

Thanks for your input. The attitude of the ABAP team is that this is a Basis issue. Is there a way to pinpoint the application that keeps getting enqueue rejects? I tried to turn on the sm12 trace but it severely impacts system performance. I also don't see the reject entry in the trace either.

Thanks,

Jonathan.

[isaias_freitas · Accepted solution]

Hello Jonathan,

You are welcome!

The following WIKI page can help you determine the application:

http://wiki.sdn.sap.com/wiki/x/oQKGEQ

The only way is to collect and analyze the enqueue log, or to already know which is the report/job/task that causes the issue .

From the basis / enqueue perspective, that is normal enqueue operation.

The application that is misbehaving.

The enqueue job is not to let already locked objects be locked again .

Regards,

Isaías

[Former Member · Accepted solution]

Hi Jonathan,

Rejected count is an accumulated data. It records since last time the system was restarted.

You need to check for a give time period to see if rejection is really a problem

Check below link on this...

http://www.sap-perf.ca/sap-lock-monitoring-and-issues-analysis/

Regards,

Prithviraj.

[Former Member · Accepted solution]

Thank you for your links, Isaias.

After turning on the SM12, the main problem was coming from SCOV, coverage analyzer. That accounts for 70% of the rejects. The rest are coming from a couple of other enqueue objects although it isn't easy to pinpoint them. They are standard SAP HR related objects. I guess we will need to investigate more.