Sizing Limits to Web Intelligence Report Server Maximum Simultaneous Connections

In Business Objects XI R2 newly created Web Intelligence Report Servers default to 50 “Maximum Simultaneous Connections” (editable in the Central Management Console, or CMC). In Business Objects XI 3.X the “Maximum Simultaneous Connections” setting is defaulted to 100! Can we read anything in to these changes in default settings? Do the default settings mean anything at all with regards to the settings you should have on your system?

Sizing Limits to Maximum Simultaneous Connections

General consensus of our sources tell us that XI 3.X is better coded and can handle more connections than XIR2, with regards to WebI Report Servers. Nevertheless, it would be quite a leap to say that all other things as equal as possible that XI 3.X WebI Report Servers can handle twice as much traffic. Seriously, don’t count on it.

I feel I should add personal experience and best practice here. I see the default setting for “Maximum Simultaneous Connections” on the WebI Report Server as a maximum setting. I have personally never exceeded it nor witness it exceeded by anyone. It is generally held that if you need more Simultaneous Connections then you ought to add another WebI Report Server to your environment. Of course, keep in mind that SAP Business Objects’ general guideline is that you have no more than 1 Web Intelligence Report Server per available CPU core (for example, a server with 4 quad-core CPUs has 16 CPU cores); so there is a limit there too.

Real-World Web Intelligence Report Server Sizing

A production system will generally run better having more Web Intelligence Report Servers with lower Maximum Simultaneous Connections. For example, a server with 4 dual-core CPUs would run better having 8 WebI Rpt Servers each set at 30 Maximum Simultaneous Connections than it would having 4 WebI Rpt Servers each set at 60 Maximum Simultaneous Connections in CMC. In the real-world tuning and balancing usually are based on observed performance within configuration guidelines.

To get your sizing in the right place you should know what you maximum concurrent users are (logged-in users plus concurrent schedule jobs). This number is essentially how many Maximum Simultaneous Connections you will need. So let’s say you never have more than 100 concurrent users, but you can at those peak times also have 25 scheduled jobs. Keep in mind that most users will only do one process at a time, but some like me will be refreshing one report while editing another simultaneously. A scheduled job will always only be one connection. So you can safely say that you require only 150 simultaneous connections (with some wiggle room).

Now your server had only 4 CPU cores in it. So this one is easy 150 divided by 4 will give you 37.5. Round that up, because I suggest you have at least 150 and that you keep the same number on each WebI Report Server. So you can set each one’s “Maximum Simultaneous Connections” to 38 using the CMC. In XIR2 this might be pushing the limits, but in Business Objects XI 3.X this should be a comfortable setting.