Excel Service Application - SharePoint 2010 (Performance Management)

Question

I have a SharePoint 2010 farm with three servers :-
Server 1 - WFE
Server 2 - CA + WFE
Server 3 - DB Cluster + WFE

I have Excel Calculation Services Started on all the servers.These are my questions

a) Do I need to configure any alternate access mappings to ensure that excel services is used evenly across all three servers?

b) What happens when excel services consumes maximum amount of permitted memory in a server ? Does the application pool automatically recycles in that case or the system crashes ?

c) The farm's user base is around 3500 average daily unique visitors.50% of them open large excel files in their browsers and does a lot of calculation. From performance standpoint what should be my correct approach towards capacity planning for the same. Do I need to add more application servers or do I need to increase the RAM in the web front end servers ?

d) Is there a way to determine the number of excel sessions created across the entire SharePoint sites in a farm at any given time ?

e) What really happens when I manually recycle the application pool in IIS that runs excel calculation services ? I have done that sometimes to prevent excessive consumption of memory however Im not really sure whether is it a good practice. Please suggest here.

Answer 1

a.) AAM has nothing to do with load balancing other than determining the URL that should be used. You need to configure NLB independent of SharePoint - e.g. using Windows NLB, round robin DNS, a proxy server or a hardware load balancer.

b.) This question is related to IIS, not SharePoint specifically. The app pool shouldn't crash as such, assuming you have configured the max memory settings correctly for the pool. As a rule of thumb the total max memory assigned to all app pools shouldn't exceed your total server memory (configure the pools to recycle when they reach a certain limit).

c.) You haven't told us how much RAM each Web server has, or the CPU/disk configuration. I suggest testing the given scenario using a tool such as Visual Studio 2010 Ultimate and using the results to determine if you need more resource (don't forget to watch your SQL servers).

d.) I don't think there is an out of the box means of determining concurrent usage. You could however use your IIS logs along with a tool such as LogParser to get a good idea.

e.) Recycling an app pool will unload the application from memory meaning you have a "clean" slate to work with. For SharePoint content app pools we tend to do this once per night - your results may vary. You don't want to recycle in the day unless you have to as it will cause a temporary performance hit for end users.

I hope that is of some use, let us know if you have any more queries.