topic Re: Is there a Shared objects memory consumption history? in Application Development and Automation Discussions

Is there a Shared objects memory consumption history?

Ruediger_Plantiko — Wed, 04 Aug 2010 08:07:01 GMT

Dear ABAP performance experts,

is there a history for memory consumption of shared objects? Transaction ST02 allows a history view for many other buffer types, but apparently not for Shared Objects.

Why do I ask this?

In one of our production systems, the 20MB limit for Shared Objects is about to be touched. From the SHMM transaction, the following shared objects participate.


Class Name                   Allocated bytes
CL_SOAP_SHM_ENQUEUE_AREA               1,960 
CL_ICF_SHM_AREA                   11,661,896 
ZCL_TAGLIB_TEMPLATE_AREA              41,536 
CL_SANA_SHM_AREA                   2,138,320 
ZCL_STATUS_AREA                       38,432 
CL_QRFC_SHM_AREA_QUEUE_TO_DEST         2,504 
CL_UGMD_ROLE_SHM                   1,012,296

I found two notes concerning the by far fattest of these objects, CL_ICF_SHM_AREA (it holds an internal table ICF_SHMRUNT with only 653 entries in our system which looks harmless. But the internal table has a deep structure: It has a component which is again an internal table, and that internal table again has a component which is an internal table! This may explain the high memory consumption).

https://service.sap.com/sap/support/notes/986790

https://service.sap.com/sap/support/notes/1071924

But before deciding about an action (like changing the buffering method with the system parameter icf/shared_memory_cache_off), I would like to know wether the allocated memory is continually growing (as could be possible if there are many incoming requests with dynamical path components, see note 986790) or wether it remains more or less fixed at this value.

Kind regards,

Rüdiger

Re: Is there a Shared objects memory consumption history?

Former Member — Wed, 04 Aug 2010 08:14:52 GMT

Hallo Rüdiger,

shared objcts will be visible in the ST02 with the very new releases, but even there no history is shown as for the other buffered objects. There is no history at other places as far as I know.

Siegfried

Re: Is there a Shared objects memory consumption history?

Ruediger_Plantiko — Wed, 04 Aug 2010 08:23:03 GMT

Hallo Siegfried,

thank you for the answer. As we are on SAP_BASIS 700, I therefor have to observe the SHMM figures daily to get the history.

Regards,

Rüdiger

Re: Is there a Shared objects memory consumption history?

HermannGahm — Wed, 04 Aug 2010 10:31:36 GMT

Hi Rüdiger,

As we are on SAP_BASIS 700, I therefor have to observe the SHMM figures daily to get the history.

this is probably the easiest thing to do.

There is a "Trace" Option in SHMM availabe which is more a "Log" than a "Trace".

With this you can write an own class that hooks in predefined cases (e.g. detach commit)

and then logs some information. This might be oversized for your task but in principle

it should be possible doing it this way. I've done this once to check how it works (the hooks,

not the size) but lost this example since i haven't done a backup (yes that happens).

Now i would have to figure it out again...

Kind regards,

Hermann

Re: Is there a Shared objects memory consumption history?

Ruediger_Plantiko — Wed, 04 Aug 2010 12:55:52 GMT

Thank you Hermann,

interesting info. I'll keep this in mind for my next shared object class!

Regards,

Rüdiger