IIRC it's not about backend slowness, it's about dropped backend connections. (i.e. Tcp doesn't respond or connection refused) It might only take 2 or 3 of these to cause the backend to be "dead". Anything more complicated than that would be relegated to a custom health check script.
-- Joe Confidentiality Notice: This e-mail transmission may contain confidential and legally privileged information that is intended only for the individual named in the e-mail address. If you are not the intended recipient, you are hereby notified that any disclosure, copying, distribution, or reliance upon the contents of this e-mail message is strictly prohibited. If you have received this e-mail transmission in error, please reply to the sender, so that proper delivery can be arranged, and please delete the message from your mail box. From: Brad Allison <[email protected]<mailto:[email protected]>> Reply-To: "[email protected]<mailto:[email protected]>" <[email protected]<mailto:[email protected]>> Date: Tuesday, October 20, 2015 at 1:31 PM To: "[email protected]<mailto:[email protected]>" <[email protected]<mailto:[email protected]>> Subject: [Pound Mailing List] When does pound decide to that the backend is "dead"? I was doing a test of removing web servers from my backend to force the load of the remaining web servers to go up and I noticed that I hit a point where the remaining web servers were so overloaded that they fell out of the load balancer. These web servers were up and still capable of taking more load. But pound had removed them and put them right back in. This is a problem because I use sticky sessions based on JsessionID, so if pound removes a web server and puts it right back in, load does not go back to that web server because the JsessionID has already been assigned to another web server. My question is: How does pound determine that a backend web server is "dead" (enough to remove it from the list and then add it right back in). I have "TimeOut" set to 120. And according to my logs the requests were not hitting a 2 minute limit, so that's not it. So how slow does the backend web server have to be before pound says that's it's "dead" and removes it? -brad
