Hi, > I could not find anything at Google. May somebody give me tips how to > resolve this issue?
If you have many connections to your loadbalancer, a slow backend and a low cache hitrate the number of connection hold open may cause problems. My first step would be to check if the number of syn-connections fits to the number of connections so if netstat -nap | grep SYN | wc -l is high compared to the number of requests per second maybe this is a real SYN flood attack after all. I checked on a system of my own serving about 70 req/s the number of open syn requests is always below 10. If there is no attack and you cannot speed up your backend or increase the cache hitrate, maybe you can use dns round robin to split the requests between more than one load balancer. Sincerely, Tobias -- LAMP solutions GmbH Gostenhofer Hauptstrasse 35 90443 Nuernberg Amtsgericht Nuernberg: HRB 22366 Geschaeftsfuehrer: Heiko Schubert Es gelten unsere allgemeinen Geschaeftsbedingungen. http://www.lamp-solutions.de/agbs/ Telefon : 0911 / 376 516 0 Fax : 0911 / 376 516 11 E-Mail : [email protected] Web : www.lamp-solutions.de Facebook : http://www.facebook.com/LAMPsolutions Twitter : http://twitter.com/#!/lampsolutions _______________________________________________ varnish-misc mailing list [email protected] https://www.varnish-cache.org/lists/mailman/listinfo/varnish-misc
