Lots of connection failures in the last hour.... Are you working on the pool Clipse ?
Not sure why it happened but occasionally some of the miners connected are opening thousands of connections and its hard to get that under control since it doesnt happen regulary or at specific timeframes.
All I know it seems to be related to cgminers aggressive way of opening new connections, right now not much I can do other than letting it pass by for now.
EDIT: Ive throttled getworks and established connection spamming even more from a few IPs (not sure if its deliberate or faulty setup) and will have to monitor if it helped.
EDIT: Taking pool down for few minutes to figure out what is causing the latest issues, its a set of ips spamming new connections if I cant work around them I will simply block them and the users can contact me afterwards.
EDIT: Im off to bed, rejects should be dropping again. Think I got hold of most of the "nastys", will look at whatever havoc that may occur once I wake up. Planning to redo most of the networking asap and also implement some realtime throttling on offending connections.