Setting “NSPI max sessions per user” to a hex value of 0xffffffff

[ia01]

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

[TonySterling]

Have a view of this:

Windows 2008 domain controllers restrict Name Service Provider Interface (NSPI) connections which can cause Enterprise Vault (EV) archiving tasks to fail

Article:TECH73507

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Created: 2009-01-13

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Updated: 2012-07-19

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Article URL http://www.symantec.com/docs/TECH73507

It has the following formula:

In some circumstance it may not be desirable to set the limit for NSPI connections to the maximum value.  As a guide, the formula below can be used to set the NSPI connection limit using the registry key above.  Please note that this is only a guide and it may be necessary to increase the limit further. In addition the below calculation does not take into account Discovery Accelerator, Compliance Accelerator and Custodian Manager.  The final value created will be a Decimal value which will then require conversion to a Hex value to apply to the registry key.  Windows Calculator can assist in this process.

Number of Mailbox Archiving tasks * Number of connection threads (per task) * 4          = A

Number of Journal Archiving tasks * Number of connection threads (per task) * 4            = B

Number of Public Folder Archiving tasks * Number of connection threads (per task) * 4 = C

Task Controller Service   = 20

Storage Service  = 32

Shopping Service  = 20

PST Migrations   = 20

Total      = 2 * (A+B+C+20+32+20+20)

[JesusWept3 · Accepted solution]

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

[Rob_Wilcox1]

To be fair I think Tony's calculations/estimates are spot on. And if you go against the Symantec recommendation then you will need to implement careful monitoring to ensure that resources don't get exhausted.

[JesusWept3]

well the thing is, i agree that its a good rule of thumb, however remember that you apply that to the 2008 DC controller.

So even in a large environment say you have 40 tasks at 5 threads, based on those calculations you would set the NSPI connections to 1,784 .... which may be great for EV, but considering you have many other applications hitting NSPI too (GOOD and BES etc)... you may end up no better off than you were etc