Memory Error dump "SYSTEM_NO_SHM_MEMORY'

[former_member425874]

Hello,

Our new Web Dypro ABAP application in production is generating a memory error short dump. Since this is our 1st Web Dynpro ABAP application, we are not really familiar with the system tuning that may be necessary. Our basis group would like us to explore alternatives to increasing the shared abap memory allocation.

OSS note 972757 talks about how ABAP programmers can release shared objects locks with methods DETACH_COMMIT / DETACH_ROLLBACK .

Has anyone tried this? I am having trouble using these methods since the class u201CCL_SHM_AREAu201D is abstract. I seem to be a bit weak in the ABAP objects area.

Any suggestions will be appreciated.

[Former Member]

Go to transaction SHMA >Monitor>Select the all the area and click on Delete icon.

[Former Member]

Hello,

What's the consequence of deleting all the areas? Beside loosing the current shared memory for people who are currently using them.

I'm facing this problem when people are using SRM shopping carts and other portal iViews.

The available memory becomes to short to allow new shared memory to be allocated.

Thanks for your help,

Regards,

Thomas

[thomas_jung]

>What's the consequence of deleting all the areas?

That really depends upon the particular shared memory area and what the application is using it for. Generally shared memory is used to cache commonly used data and avoid duplicate calculations or database retrevals. This is how it is used in the WDA framework. Clearing the areas or turning off shared memory in the WDA framework can lead to performance problems, especially during startup.

However other applications might be using shared memory for temporary storage or cross session communication. Clearing areas in these cases can lead to short dumps or data inconsistencies.

[thomas_jung]

Are you actually using Shared Memory in your application or is it just the little bit of the WD Framwork that is using Shared Memory?

If it is just the framework, then this should need very much Shared Memory. I would say that if you are getting this message for just the framework then you should allocate a little bit more shared memory as your total allocation must be very small. What is your total shared memory size? The framework usage of shared memory can have a very positive impact on performance as the most commonly used functionality can be place in shared memory and reduce a large number of repetative processing. You can dispable the usage of Shared Memory with the Application Parameter WDSHAREDREPOSITORY - although I wouldn't suggest that unless absolutely necessary.

[alejandro_bindi]

In my case, it's been always the standard CL_WDR_GLOBAL_TASK_AREA giving problems.

I think they may've fixed it now as I'm not finding anymore dumps.

[former_member425874]

Thomas,

Thanks for the feedback. My application is calling some RFC's but is not intentionally using shared memory.

I am not with basis so I am note sure of my answer....but for area "CL_WDR_GLOBAL_TASK_AREA" we have an allocation of 8,192. When I checked, 2,896 was occupied before my application ran. The memory in this area seems to accumulate without releasing right away.

[former_member425874]

Thanks. Did you apply note 1107298?

[alejandro_bindi]

Not sure what Basis did. But the note didn't apply to our system as it was for 710 systems.

However it describes the same issue so it may have been downported or related to a 700 fix, that's why i've mentioned it.

Regards

[former_member425874]

in our 7.0 system, I don't see WDSHAREDREPOSITORY as a possible application parameter using the drop down list in SE80. I would like to disable shared memory for my application. Is this a 7.1 feature?

[thomas_jung]

That application parameter is available to 7.0. It is listed in the 7.0 online help:

http://help.sap.com/saphelp_nw70/helpdata/EN/7b/fb57412df8091de10000000a155106/frameset.htm

What SP level are you? Maybe your SP level is too low to list this application parameter.

However you should strongly consider the implications of using this parameter. The WD Shared Repostory doesn't require all that much space. In my system the total shared memory to WD is less than 1Mb. You can view available and allocated Shared Memory in transaction SHMM.

[former_member425874]

We are at SAP_BASIS SAPKB70012. I understand that performance may be conpromised, but we are at the point of abandoning this application. We are not prepared at this time change the allocation of shared memory.

[alejandro_bindi]

Check note 1107298, see if that applies to you.

We're on a 7.0 system though and had exactly the same issues, I've not been told how (and if) the Basis team found a definitive solution.

What I've noticed is that the problem increases if you just reload applications with F5 instead of closing the browser and reopening.

Hope this helps.

Regards