Session State lost when NLB host crashes

Doug,

The only way to keep your session information in the
event of a server crash would be to set up a third server
to manage that info for both web servers. Since you are
using .Net, you can use either a State Server or SQL
Server to accomplish this task. See the following link
for more info:

<a style='text-decoration: underline;' href="http://www.microsoft.com/technet/treeview/default.asp?" target="_blank">http://www.microsoft.com/technet/treeview/default.asp?</a>
url=/technet/prodtechnol/windowsserver2003/proddocs/deploy
guide/iisdg_net_tezu.asp

Sincerely,
Invotion Engineering Team
Advanced Microsoft Hosting Solutions
<a style='text-decoration: underline;' href="http://www.Invotion.com" target="_blank">http://www.Invotion.com</a>
 >-----Original Message-----
 >What happens in the following scenario:
 >1) I have two Win2003 servers configured with NLB
 >2) They are both running an ASP.NET application
 >3) Affinity is set to single
 >4) The application is using Session vars and Cache vars
 >5) Server A crashes
 >
 >A) Users who were tied to Server A are redirected to
 >Server B AND Server B has all the same Session and Cache
 >information available to the users.
 >B) Users who were tied to Server A are redirected to
 >Server B BUT Server B does not have any of the Session
or
 >Cache information.
 >C) Users who were tied to Server A get a nasty message
 >and need to start over.
 >
 >NOTE: I'm hoping for A...expecting B...and would wonder
 >about the usefulness of NLB if it was C.
 >
 >TIA, Doug
 >.
 ><!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: Session State lost when NLB host crashes 

You can store the ASP.Net session state externally (eg in ASP.Net Session
State server). Then, when the user is redirected to server B, option A will
be what happens.

Otherwise, option B will probably happen, and option C may happen if you
have code that relies on certain session information being present and
doesn't check to make sure that it's there.

Cheers
Ken

"Doug" <anonymous.RemoveThis@discussions.microsoft.com> wrote in message
news:038d01c3afb2$eb2e5eb0$a401280a@phx.gbl...
: What happens in the following scenario:
: 1) I have two Win2003 servers configured with NLB
: 2) They are both running an ASP.NET application
: 3) Affinity is set to single
: 4) The application is using Session vars and Cache vars
: 5) Server A crashes
:
: A) Users who were tied to Server A are redirected to
: Server B AND Server B has all the same Session and Cache
: information available to the users.
: B) Users who were tied to Server A are redirected to
: Server B BUT Server B does not have any of the Session or
: Cache information.
: C) Users who were tied to Server A get a nasty message
: and need to start over.
:
: NOTE: I'm hoping for A...expecting B...and would wonder
: about the usefulness of NLB if it was C.
:
: TIA, Doug
 >> Stay informed about: Session State lost when NLB host crashes 

"Atanu Chatterjee" <atanuchatterjeecal DeleteThis @hotmail.com> wrote in message
news:2fc701c3b012$64c86360$a601280a@phx.gbl...
 > I think LB is implemented in ur DNS server and is done by
 > ISP, u can ask him if he can maintain LB keeping the
 > session state, What i mean is , a client request suppose
This is not possible.
What you mean is HTTP TCP/IP stickyness. But this does not keep the
application asp.net session

 > goes to server A for the 1st time , any subsequent request<!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: Session State lost when NLB host crashes