cons and pros of installing LiveCache on SCM server

[Former Member]

Hi All,

Currently we installed LiveCache on our SAP SCM server (AIX).

I know lots of companies have a separated alone LC server to make sure the performance, so here I would like to consult you, what's the cons and pros of installing LC on SCM server ? I would like to know if there's any tool or suggestion on the LC/APO landscape design.

I am not sure if or how much will this structure impact the performance of APO peak time, I think the APO and LC will both take lots of CPU/Memory during peak time.

Thank you very much.

BR,

Eric

[former_member188883 · Accepted solution]

Hi Eric,

Customers having LiveCache on separate server or partition have followed distributed SAP installation where we can install Livecache on different server partition.

This will depend on volume of data processing which Livecache needs to perform.

You may have Livecache and SCM system on single server partition with appropriate sizing done for both the applications.

Hope this helps.

Regards,

Deepak Kori

[Former Member · Accepted solution]

Hi Kori,

thanks a lot for your reply, and I would like to know where could I know which volume of data processing with Livecache is worth us to move LC to another separated server?

Thank you very much.

BR,

Eric

[Former Member · Accepted solution]

hey Eric - take some simple numbers - how much memory is assigned to liveCache today?

How much in comparison is generally taken up by SAP? (primarily by D+W procs)

How much is assigned to your RDBMS (e.g. ORACLE)?

What is the driver for this consideration? Are you having performance issues? If so is the OS showing signs of a bottleneck with CPU, RAM or disk ios?

I don't see a need for a separate server unless you are constrained on the hardware. It adds extra complexity (and an extra OS to manage/patch) and these days servers tend to come with a lot of processing power and memory. The way I see it, in the past when memory was very much a constraint per server/instance this was more prevalent as way to get around system limitations.

[Former Member · Accepted solution]

Thanks a lot Jamie.

Our APO has around 650G physical memory and around 430g physical memory been assigned to LiveCache... we have 60 CPUs and 15 of them been assigned to Livecache.

currently we don't have any performance issue but I was told the workload probably 2-3 times increased in next 2 years so I start to considering if it's necessary to separate into 2 servers for better performance.

for now our bottleneck of LC only be very high collision rate, around 400% to 4000% for several region.

[former_member229109 · Accepted solution]

Hello Eric,

I recommend you to have the Early Watch report & http://service.sap.com/quicksizing service.

You could use the DB analyzer to check the liveCache parameters & find the bottleneck in the liveCache.

If you have the OS resources to run the applications & liveCache on the same server, there are no issues. Just check the memory, CPU, SWAP settings/configuration/availability before to set the liveCache memory parameters & MAXCPUs.

Please review the information in the SAP notes:

1972803 - SAP on AIX: Recommendations

1128916 - FAQ: SAP MaxDB/liveCache heap management

Regards, Natalia Khlopina