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asp.netexceptioniisviewstatemachinekey
eozcan
eozcan

Reputation: 115

Getting ViewStateException: Invalid viewstate while Machine keys are the same

I have 8 host behind LB and all of them are single process(not web garden). Despite setting all of them with the same machine key from iis as shown below, I'm still getting Invalid viewstate exception rarely.

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There similar questions but none of them helped me(I've no server with pending updates or restart as in the other questions or i'm not using server.execute etc). So please don't flag as duplicate. Are there any alternative ways to prevent this exception?

Thx

Upvotes: 0

Views: 758

Answers (1)

Jalpa Panchal
Jalpa Panchal

Reputation: 12749

Normally, This is because of the difference in Machine keys in different servers. We use Web Farm for High availability. In this case, if a Client sends a request then the Load balancer decides, which webserver to serve the request. It happens several times that another request might be served by another server. So here is the issue.

As we know, view stat is Client-side state management techniques and the data travels with the request and response. So if the view state is encrypted with some machine key and in other requests if handled by another server and that has different machine key, it would not be able to decrypt it and will through the error.

Every server generates a new key when it is set auto. and even sometimes any recycle of the app domain will generate a new key when it is set to auto. It means we cannot use the default auto-generated key. So here the solution is to use a specific key in the machine.config to prevent automatic key generation on each process start.

One another flexible approach, however, would be to add a MachineKey section to the web.config file of your web site. This would not require to make the changes on every web server.

another way is you could try to set below code in machine.config:

enableViewStateMac="false"

Upvotes: 0

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