Lock Table Overflow

[Former Member]

SAP 4.7 6.20 - Windows Server 2008 - Oracle 10g

I have many error messages in tx sm21 :

GEG Lock Table Overflow

GEA Internal lock administration error

GZZ EqSetCluster() ; rsc=16 enxxmenq1905

The error happens countinuasly for 8-9-10 minutes and then everything returns to normal.

No dumps in st22, but some jobs lose the schedule. I need to reschedule some of them.

I was informed by some consultants that the transaction VT02N is using an average of 28500 lock entries by user.

The value of the parameter enque/table_size is 30000.

But the consultants say that we should not increase this value.

Because VT02N has a lot of customizations here, we should investigate the program.

I had never seen this error before, so I need some help to understand the situation better.

I've already read a lot of ducumentation and the more I read the more I get confused.

1) What kind of lock is that ? There is not so many lock messages in tx sm12. And there is nothing in tx db01.

2) What kind of mistake could someone do in a program / exit / include to produce these errors ?

3) How could I discover if a program is really producing so many locks ?

Thanks in advance,

Eduardo

[sunny_pahuja2 · Accepted solution]

Hi,

Lock table overflow generally occurs because of following reasons:

The maximum number of locks in the lock table is subject to an upper limit that is set by the profile parameter enque/table_size. The profile parameter enque/table_size determines the size of the lock table in KBs. You can use transaction SM12 -> "Extras" -> "Statistics" to determine both the maximum number and current number of entries.

The lock table may overflow if:

• the lock table configuration is too small

• an application sets lots of locks

• the update hangs and, as a result, numerous locks inherited by the update task exist

So, now you have to troubleshoot why this is getting overflow so frequently.

Thanks

Sunny

[Former Member · Accepted solution]

Hi Sunny,

My problem seems to be the transaction VT02N which has a lot of customization...

When a transaction has performance problems I go to ST05 in order to check the SQL commands.

But I don't have any reference about how to check lots of locks generated by a transaction...

Could you please give me some clues about how to troubleshoot locks ?

Thanks in advance,

Eduardo

[sunny_pahuja2 · Accepted solution]

Hi,

When you face this problem, then you can go to SM12 and then go to Extras --> Top Capacity used. There you can find out which user is trying to lock which table and have maximum locks. And then you can troubleshoot more.

You can check SAP note 746138 for troubleshooting on lock table overflow. Also, check below thread:

Thanks

Sunny