How many CMS in a BusinessObjects Business Intelligence Cluster Platform

[marino_pagot]

Hi everybody,

first of all, happy new year!

I have to set up a BusinessObjects Business Intelligence Platform (4.2 or 4.3 version) in cluster mode.

The main question is: how many CMS (Central Management Servers) should I created in a cluster to obtain the best performances (regardless of availability and failover)?

Are there SAP best practices regarding this specific aspect?

For example only one CMS (regardless of the number of nodes) because more than one can create slowdowns due to communication and synchronization between them?

Othwerwise, in the reverse, one CMS per node (regardless of the number of nodes) becasuse there is a load balancing between them?

Or a middle ground between the 2 previous options?

Other options?

And does it depend on the number of nodes?

I want to point out that I'm not interesting to achieve the availability but the performances. So if the best choice is only one CMS and the node with this CMS is down, for me is not a problem.

I've searched in SAP notes (for example SAP note 1795810), in the SAP help documentation, etc. but unfortunately I didn't find anything interesting.

Thanks in advance

Best Regards

Marino

Methode Support

[JohnClark]

I'm not sure there is a best practice for how many CMS services to run. There is a lot to take into account.

We have had environments, and actually do currently have environments that utilize both scenarios that you are asking about.

In the past, we have had some four node clusters with a CMS running on each node. This was primarily because each node was primarily a single stack server, just clustered with some other single stack servers.
Currently we are running an 8 node cluster with 2 CMS services. The 2 nodes that run the CMS are primarily dedicated to running the CMS, that is, no scheduling services, no Crystal Reports, no Web Intelligence.

We run 2 CMS services for failover redundancy. This is our primary consideration for how many to run.

There have been any noticeable performance differences related to the CMS between these configurations. There was some tweaking done to the CMS in the 8 node cluster that are supposed to improve throughput but that was not in response to any specific issue with the CMS.

We did implement the recommendations from 1981894 - "Number of Objects in CMS System Cache" Metric.

Check out the various solutions in this KBA and see if there are any that you can benefit from: 2232733 - Error: CMS system database is overloaded, general performance issues, and/or deadlock issu....

[Joe_Peters]

I'd suggest starting with this article: 1570271 - How to find sizing information for SAP BI Platform 4.x - SAP for Me

It has links to the BI4.2 and BI4.3 sizing guides.

As with most sizing questions, there's not a single answer - it'll depend on your specific implementation. But in general a single CMS can support 500 concurrent sessions.