ACE without a probe configured

Unanswered Question
May 18th, 2008
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Can someone please tell me how the ACE handles connections to a farm/rservers when there is no probe configured in a context?

For example, if a rserver was to drop off the network how would the ACE handle this situation in respect to current connections and new connections?

How would the ACE realise a rserver has died? What about if a specific port didnt respond and yet the rserver itself was ok?

Is there some default timeout and/or behavior that is different to when a context has a probe configured?



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ciscocsoc Mon, 05/19/2008 - 00:05
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Hello Cameron,

If there isn't an active probe then the ACE will not be able to make reliable LB decisions. Without a probe current connections would hang and some new connections would be attempted subject to the predictor algorithm.

The ACE would not realise the server had died . If a specific port is used then your probe needs to test for it. Just using PING tells you you have a basic IP stack but not that a service is running.

I've heard about passive probes but haven't seen any documentation for them.

Use a probe and decide on the correct failaction for your service.




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