-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 Frederik,
On 3/18/14, 10:22 PM, Frederik Nosi wrote: > Each apache httpd talks with every tomcat. > > mod_jk is configured with load balancing by business, sticky > sessions, only one try for ajp worker (so if it's busy i dont add > more stuff to the poor worker) and only 1 retry for all load > balanced workers, in short, here's the interesting part of my > conf: > > worker.worker_lb.balance_workers = w1, w2, w3, w4 sticky session > on, sticky session force = off ecc Could you post the whole configuration without editing? > [...] > > > > Now, even with this settings, on peak times i have an > amplification effect, all tomcats are busy, mod_jk reaches atimeout > and retries again and again ... in a death spiral for the poor > cats. > > This behaviour brings me two problems: > > 1) Even if apache httpd / mod_jk timeouts (read_timeout) from his > side this does not stop the tomcat thread proccessing that request. > It goes sometimes on and on but after all finishes the request. > This seems a resource waste, is there a way to let tomcat know > that mod_jk droped the connection and stop proccessingthe dropped > request? I tried to find a way to get this behaviour without > success, so any suggestions are welcome. > > > 2) I noticed that the default behaviour of load balanced workers > and AJP workers is as follows: > > a) ajp worker reaches retry_timeout, at this point retries again > to the same worker once, thus amplifying load. This onewas easy to > solve, just add a "worker.w1.retries = 1" and this does not happen > anymore > > b) Load balancer worker goes to the next ajp worker.. till the > last one, than does another round of requests: > > lb -> w1 -> timeout [...] lb-> w4 -> timeout > > LB try 2 lb -> w1 -> timeout [...] request fails. > > The second round to the workers IMHO is wasteful, but easy solved > with: "worker.worker_lb.retries = 1" > > So at this point for every request all the busy tomcats get only > one request. I tryed finding a way to tell the LB worker to try > just once, only another worker for request but i didnt find an > option for doing this. Well, as i had an each to scratch i made a > patch that adds an option to a LB worker telling how much times to > retry before giving up, i'm glad to post it if somebody is > interested. Not sure it's perfect, but works for me. > > > Now, my questions: > > 1) Am i doing something wrong? 2) Is there a way to make a tomcat > thread stop proccessing when AJP timeouts? - -chris -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 Comment: GPGTools - http://gpgtools.org Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ iQIcBAEBCAAGBQJTKZ5iAAoJEBzwKT+lPKRYeowQAJ1XufNZe0mc/DFwGHiIPYFK 4mqyVX00hjSwMQTSwxsTuFygiTMyTTgezsbg+EkoiDdMFtMKVRt3QZpXzCAWOthr DWYSGcnnEONDcjWv4WMaPZ8cCnT4NCh/0FmAjbCAcVv+RiJBeoOEuNuIDX4DkS71 +4HmvUB9KwQGrSnAmtS17gA6Wauf4jW0QVe/yS642Kxv+1njFFp+n0Ezx8DnzJQr VyRaKC7ITQTiAMbgHoYUOq+7Nwy1wOfRiwkfvWY8WNdJ1xOZJsicu5wnU1i4RDkp rpUvhMvMJjvqO6waHO8HYcqoAhakOPBclTDpD24JuMlL5fJJVOMiFhD4iRp83tGr X+FxMHZBTMlVhsz7ve+gQniy9zAvsTMJi5JMSkMO04WHRuqzY6dd4Iw7vrSm+LIQ JfTUOS2Bv1NXv4MOwBCdwndQLftPDDmi1TVgFuoJH8BmeZPKqoLyGKbsOpIQkYFz aZHtSViccTcNXQwQLl0pk9UVbYzGiRT4LdLFqRGEtq1yRdU7X3H9wuKkbQmRVrFe Ou0xnx5/LF7RZ2cpeVnV5stZGTlTlnrlmkRX++78kplvoo7RRLP6J8A5Xmxk9zbN Z8d8JWkNkoy1lbQr9tPaSR5A77qjwBChl3L6Elq7Gc3B1JV8SNJs8Pxau0uSm3dI gSnf9kDocRm8ta6Ykgck =PCNV -----END PGP SIGNATURE----- --------------------------------------------------------------------- To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
