Setting “NSPI max sessions per user” to a hex value of 0xffffffff
Hi,
As EV recommended value for “NSPI max sessions per user” is 0xffffffff, our customer is unwilling to set this to maximum for the following reason
As stated in the Microsoft kb article,
Note While the upper limit of this setting is 0xffffffff (or 4294967295), configuring the server with a value larger than the default will consume additional memory on the server – one new page per connection. If the value is set too high and too many connections are created for each user application instance, the server will run low on memory or become completely unresponsive. The lower default NSPI connection limit in Windows Server 2008 was based on customer experience, where previous operating systems would allow themselves to be overwhelmed by third party products in what amounts to a denial of service attack. Use a common sense approach to increasing beyond the default value; for example, start with decimal 250 (hex 0x000000FA), then test to see the memory overhead created and that the errors have ceased. Your long-term solution must be to contact the vendor of your NSPI product and ask them to change their behavior; the registry value is only as a workaround to provide error relief.
Now, if there any optimum recommendation for this to work better with EV 10.0.1? Can we start with a minimum value or any recommended value lower than the max 0xffffffff?
Number of mailboxes 3000, spread across 4 Exchange servers.
Many Thanks
I worked for a large enterprise when this issue came up, and MS said do NOT set this past 10,000, and they actually refused to set it any higher than that, and we never had any issues what so ever in regards to NSPI connections.
All the issues we saw were regarding throttling policies on Exch2010, and on an EV Server the errors are the exact same as NSPI exhaustion