Session losses (Cookie)

Hi.

 

We are encountering a strange problem since we upgraded from 9.x to 10.x.

 

Once in a while, let's say, once in a week, we have a large amount of users not being recognized with their Cookie.

 

The problem looks like this:

 

 

We have about 70 Webservers in one pool and users get sticky on one of these servers. Persistence is done by BIGIP-Cookie.

 

But sometimes the Loadbalancer has problems with the persistence. Usually the requests go to i.e. Webserver1, but then one single request goes to i.e. Webserver55, the next request again returns to Webserver1. When we have this problem, it goes for a whole day, or night, sometimes even for two or tree days, then it disappears again.

 

 

Is this a problem someone has noted before? Or maybe someone has an idea if it would be possible to do some logging on such behaviour? Or what could be done to find out more? We are quite idealess, as it follows just no logic.

 

 

Regards.

 

 

Markus