Sessions / Clustered Servers?

[Rob Meade]

Hi all,

At work we have 2 servers in a cluster for our web apps.

One problem we have experienced (along with many others!) - is that if a
user is logged into one of the applications on server a for example and it
goes offline or fails their session is lost also - even though the
application becomes available on server b.

I have heard that it is possible to either exchange the sessions between
clustered servers or store them in a SQL Server database (probably
preferred) so that we could then restore them if such a failure should
occur.

Can anyone shed any light on this for me? Or give me some URL's to check out
and read.

Sorry this isn't a 100% pure IIS question - its obviously partly ASP also.

Thanks in advance for any help you can offer.

Regards

Robb

PS: Windows 2000 servers, SP3, Application Center 2000 SP1 (sp2 about to be
applied), SQL Server 2000 SP2 (sp3 about to be applied).

 

[Sean Bogan]

Rob,

Your application needs to be 'cluster aware', which is a loosely defined
term. Often, applications will use dynamic thread pools for users, which
means the sessions you are referring to have already been assigned to the
node that fails, which is why the session won't failover with the
application.

Talk to your developers about introducing code into their application that
periodically looks for a hearbeat from the server and set the application to
reestablish the session to the virtual server if the heartbeat fails.

Hope that helps,

Sean Bogan
Microsoft Consultant
Collective Technologies
www.collectivetech.com

 

[Rob Meade]

...

Your application needs to be 'cluster aware', which is a loosely defined
term. Often, applications will use dynamic thread pools for users, which
means the sessions you are referring to have already been assigned to the
node that fails, which is why the session won't failover with the
application.

? /

Talk to your developers about introducing code into their application that
periodically looks for a hearbeat from the server and set the application to
reestablish the session to the virtual server if the heartbeat fails.

hehe - I am one of the developers! )

How would one do that in ASP then? We are aleady checking for a Session
variable each time the pages load in our applications, this is to check that
the user is logged in etc....is this sufficient?

Any further help would be appreciated,

Regards

Rob