On Fri, Sep 07, 2012 at 02:13:42PM +0800, lzc6 wrote: > > hi.guys... > > We use the haproxy with 10 tomcat server at the backend, the request > probably about 500 million every day, > > Recently we found haproxy there are a lot of 503 erros.... > > after the analysis of the log, probably a total of 50 000 503 errors daily, > which the CC type accounted for 80% > > through View document we get the CC explanation: > > CC > The client aborted before the connection could be established to the server. > This can happen when haproxy tries to connect to a recently dead (or > unchecked) server, > and the client aborts while haproxy is waiting for the server to respond or > for timeout connect to expire. > > > But the tomcat servers behind are all running well, > so i wanna to know if there are other reasons to cause so many 503 ? > with solution will better...
I think that you're experiencing connection storms or port scans. Basically an attacker is sending connections and closing immediately, before the server has the time to acknowledge the connection request. It's also possible that your tomcat server's backlog is too small and that clients close the connection while they're pending on the servers. Could you provide some of these lines with their timers and connection counts ? Regards, Willy
