I was reading Nginx documentation
persistence session using cookie and below is from documentation
A request that comes from a client not yet bound to a particular server
passed to the server selected by the configured balancing method.
requests with this cookie will be passed to the designated server. If
designated server cannot process a request, the new server is selected
if the client has not been bound yet.
The last line says that
If the designated server cannot process a request.
What does it mean to say “the server cannot process a request.”
Does it mean the server was down ?
or does it mean server responded with some error code ?
or does it mean that it did not responded in a certain time interval ?
or does it mean that max number of connection limit is reached on that
Let say there were 3 backend-server and we are using session persistence
Now assume that 2 of the backed server goes down so niginx will route
request to 3rd server
Now 2 other server came back online, will niginx use the other 2 server
route the request even if request have the persistence cookie for 3rd