ReportServer Forum

msmith

Member

From: Canada

Registered: 2015-01-25

Server and JVM sizing

Hi,

Are there any sizing guidelines or data points for configuring JVM parameters for ReportServer installations?

I'm looking for something like - x concurrent users tested with y MB of heap and z MB of PermGen and ## CPU cores.

Thanks,
Mike

Thorsten J. Krause

Guest

Re: Server and JVM sizing

Hi Mike,

this very much depends on your data and the kind of reports you are running, so it's not easy to give a definite answer, but perhaps I can give some guidelines. Let's start with the PermGen space - that one is easy: PermGen space is a static thing, it mainly holds the application classes and once these are all loaded usage will not increase any more. We know 256mb are fine and providing more will not improve anything. As future ReportServer version might need more perhaps just go with 512mb, it's one thing less to worry about when updating.

As for the heap: The task that requires the most memory is generating the actual report documents (e.g. pdf or excel files) in a worst case scenario we have to keep the entire uncompressed document in memory (in most cases we don't but lets just look a this worst-case)
so we could do a calculation like this
(avg-report-size / compression-ratio) * concurrent-users
so lets fill in some numbers: (5mb avg-report-size / 1:20 ratio) * 50 = 5gb
Which sound about right: Medium size instals, with 250-500 users (non concurrent) we usually set up with 6gb heap.

cpu: As with memory, cpu is mostly used when generating report documents but usually the bottleneck is the underlying database and not the ReportServer server. If you are on a phyical server I'd say anything recent will be fine, in a virtual environment I probably wouldn't go with less than 4 vcpu-cores, but truth be told, I don't remember that cpu power on the ReportServer server ever was an issue. It's much more important the database can deliver the results fast enough.

One additional thing you might want to keep in mind is tmp space: When creating reports, especially in xlsx or docx format there are huge intermediate results that we offload to disk. For a 5mb excel document this can easily mean a 1gb tmp file. So make sure ample temporary space is available.

Cheers,
Thorsten