Enque backup file grows - why?

[Former Member]

Greetings.

Enque backup file(ENQBCK) has enormous size (aprox. 700Mb) and continues to grow.

Even there are no canceled or current updates in the system this file doesnt clean itself after system restart so the system starts half an hour.

Have any clue?

R/3 4.7/200

kernel 6.40 patch level 247.

Thanks in advance,

Mihail Groshev.

[Former Member]

hii

are you using a seprate enqueue server,in that case the server will write to that file.

what you can do is stop the enqueue server and delete the log file and start it again

This is a problem that occurs in kernel 640 and can be removed by updating the kernel

Rohit

[Former Member]

Im not using standalone enque server - two enque processes are working on CI.

Yes, i can delete this file, and i did it before - but its not an option, i want to solve the problem.

And PL of the kernel is rather high, i doubt the problem is solved in future releases - do u have any sap note about it? I couldn find any, just for old PL of 640 kernel.

Thank you for your reply.

[Former Member]

refer to Note 857439,it might be of use

Rohit

[Former Member]

Yes, ive read this one.

Unfortunately it says the following:

"This problem is corrected with the CST Patch Collection 28 2005, which is contained in Kernel Release 640 as of Patch 81"

And I have patch 247.

Mikhail.

[Former Member]

Hi

I did some tests and they show:

- the ENQBCK file size is relative to the enqueue table size, ENQBCK is approx. 1/3 of enque/table_size

- if you shrink enque/table_size the file does not shrink until you stop SAP and delete the file

- only enqueues with the backup flag set, will be written to the ENQBCK file

What is your enque/table_size?

You already mentioned that you found no problem in your update system, but if the ENQBCK file grows, this points to a problem with update. Can you please double check SM12 (look for entries with the backup flag and also look at Extras -> statistics -> "to the backup file"), SM13 (try older from date's as well), and the dev_wX files of your enqueue and update work processes.

Best regards, Michael

[Former Member]

Hi, Michael, thank you for reply.

Enque table is rather big - 2Gb.

Updates are ok, no problems here.

Mihail.

[Former Member]

Ok, your enqueue table is WAY too big!

ENQBCK is approx. 1/3 of enque/table_size

This is why the ENQBCK file is so large, i checked several systems and the file size was always at least 1/3 of the enqueue table size. I really don't see any reason to have such a large enqueue table. A enque/table_size of 200mb for example can support up to 250'000 enqueue entries, which is rather large already.

Best regards, Michael

[Former Member]

You're right, i've already shrink table size to 160Mb after analyzing enque statistics more attentive.

And I understand that max. size of the file is aprox. 1/3 of the table size.

But why entries in the file arent cleaned up?

According to SAP documentation, if there are no "to-be-started" updates in the system the file should not contain any records.

Im confused.

Mihail.

[Former Member]

As i said earlier, to shrink the file, you have to delete it, it will be recreated with the next SAP start (or more exact enqueue server start). If the file still contains entries, then be extra careful. You are right, usually there should be active update tasks in this case. If you cannot find any, it might be helpful to contact the user holding the locks and double check with him, if there are no transactions active anymore. Generally the same procedure of note 857439 can be used.

Good luck, Michael

[Former Member]

Hi Guys,

Can I know in what system do you set the enque size to 2GB. I've tried on R3 4.7 ext set 2 32 bits today, and the system had a problem with lock mechanism.

Now, I'm wondering how do you set the value bigger than the advice max size (100MB). Please clarify.

Edited by: Eida Hanafiah on May 5, 2009 2:19 PM

[Former Member]

Hi Gurus,

Is it possible to have two Enqueue process/Server? Please clarify.

Thanks

Ahamed

[Former Member]

@Ahamed: A system can have exactly one enqueue server. One often speaks of the central instance, or central services (message server + enqueue server). The enqueue server can have multiple processes, but this is not recommended unless you have good reason to do so.

Regards, Michael

Edit: for dual stack systems, java does have its own separate central services.