form on coldfusion page losing form variables

Report · Feb 13, 2009

OK, I am having a very strange problem. Several applications on our
production web servers have started manifesting the same symptom. On
the login page, you have a couple of fields for account name and
password. When you hit submit the action page says it can't find the
form variables. These are on a cluster. If you go to the servers
individually, then everything works as it should. Our network people
claim that we are not shifting from one server to the other. Has anyone
else ever seen this behavior before on a single server?

Report · Feb 13, 2009

I have.

Check your http logs. What we found was that the page request would be satisfied twice, once with the form and once without. We never figured out why or how to stop it.

Report · Feb 15, 2009

Hi,

I have not seen that specific behavior on clustered or single web-servers.

You did not write if you are using any cluster features of ColdFusion, but I assume you are using as stand-alone configured ColdFusion servers, and through LoadBalancer configuration (sticky cookie) you are making sure that users are always sent back to the same server.

I would not expect the problem you have to be caused by such a load balancer configuration, but companies who implement load balancers often also use Proxy-servers, and now well they can mess up a lot of things with caching.
(even Dan's problem could be caused by a proxy server: first request to verify if the requested page still has the same date, and then the request is actually sent to the server itself for execution).

A quick way to verify if a proxy is messing with you is to attach any URL parameter: "www.mysite.com/index.cfm" may be cached, but "www.mysite.com/index.cfm?user=12345" should not be served from the cache and instead get sent to an actual web-server to return a customized response.

Cheers,
fober

Report · Feb 19, 2009

These are stand-alone servers that being load-balanced. They are supposed to stuck on the same server until the session ends. If we go to the individual servers and run the applications, it works. Otherwise, it fails randomly.

quote:

Originally posted by: fober1
Hi,

I have not seen that specific behavior on clustered or single web-servers.

You did not write if you are using any cluster features of ColdFusion, but I assume you are using as stand-alone configured ColdFusion servers, and through LoadBalancer configuration (sticky cookie) you are making sure that users are always sent back to the same server.

I would not expect the problem you have to be caused by such a load balancer configuration, but companies who implement load balancers often also use Proxy-servers, and now well they can mess up a lot of things with caching.
(even Dan's problem could be caused by a proxy server: first request to verify if the requested page still has the same date, and then the request is actually sent to the server itself for execution).

A quick way to verify if a proxy is messing with you is to attach any URL parameter: "www.mysite.com/index.cfm" may be cached, but "www.mysite.com/index.cfm?user=12345" should not be served from the cache and instead get sent to an actual web-server to return a customized response.

Cheers,
fober