ODP Cleanup

[Former Member]

Hello,

in my productive system when I analize traces in my system for low transaction I see the execution of the statement ODP Cleanup and spent 1000.0000 ms.

I see in the sdn that the parameters to customizing this functionally are:

[original link is broken]

dbs/db4/odp_threshold '800' Number of ODP's to be left open

dbs/db4/odp_commit_threshold '810' Number of ODP's that should trigger an ODP cleanup at commit

dbs/db4/odp_open_threshold '850' Number of ODP's that should trigger an ODP cleanup at open

Can I increase this parameters? untill wihich values?

How affect this parameters to the performance?

Why does not this parameters appear in report rsparam ?

Thanks in advanced.

[JanStallkamp]

Hello Francisco.

> in my productive system when I analize traces in my system for low transaction I see the execution of the statement ODP Cleanup and spent 1000.0000 ms.

>

> I see in the sdn that the parameters to customizing this functionally are:

>

> [original link is broken]

>

> dbs/db4/odp_threshold '800' Number of ODP's to be left open

>

> dbs/db4/odp_commit_threshold '810' Number of ODP's that should trigger an ODP cleanup at commit

>

> dbs/db4/odp_open_threshold '850' Number of ODP's that should trigger an ODP cleanup at open

>

>

> Can I increase this parameters? untill wihich values?

Yes, you can increase this parameters. But that is not very common and not described in any documentation I am aware of. The default values should work in most situations.

> How affect this parameters to the performance?

With a higher value for the ODP threshold more files can be held open in memory. This will increase performance. As a drawback memory consumption will be increased. If you set this value to a very high value you will need too much memory and the system starts paging resulting in a severe performance decrease.

> Why does not this parameters appear in report rsparam ?

Not all profile parameters have been maintained in the transactions RSPFPAR and the other profile parameter maintanance transactions. We have introduced several parameters to these transactions recently but the ODP-parameters are not documented up to now as they were considered to be more 'internal' profile parameters.

I would suggest not to change this parameter unless you see very many cleanups in your traces and you are sure that you have sufficient memory.

Best regards,

Jan Stallkamp

[Former Member]

Hi,

exactly the last thing of Jan is the point here:

We typically ONLY see long ODP Cleanups, when the memory is exhausted ;-(

=> to increase the values in this case is not very helpful ...

(if you would see "too many" but fast cleanups, then it could help to increase the parameters)

Regards

Volker Gueldenpfennig, consolut international ag

http://www.consolut.net - http://www.4soi.de - http://www.easymarketplace.de

[jo_degraeve]

Hello there

I've been interested in the ODP cleanup (and the sometimes long responsetime caused by it) for quite some time now.

This morning I traced a user session (user was complaining) and ODP cleanup was reported as the majority of the time spent in the transaction.

I recall an older SAPNote (732079) where SAP at some point launched an experimental change to bring the ODP cleanup time outside of the user's response time by actually performing the ODP cleanup offline after the user transaction completes.

I'm wondering if SAP have progressed this experiment, and if not, why not ?

Jo

[former_member192743]

Greetings,

We haven't seen long ODP cleanup times in recent.

If wouldnu2019t mind, please open an OSS ticket to BC-DB-DB4 and attach the trace you have taken. The subject should read u201CLong ODP Cleanup Timesu201D.

u2026 Eric