Hi list, I've a strange behaviour on a cluster of lighttpd which I can't explain.
Here are the facts: Xeon CPUs (2x Quad Core) Gentoo Linux Kernel 2.6.27.7 Glibc 2.6.1 Lighttpd 1.4.20 Cluster using LVS-DR What happens: Lighttpd simply doesn't accept connections. In the tcpdump on the realserver I can see the SYN packets arrive but the connection isn't accepted on the server socket. There's no SYN-ACK travelling out, neither a RST or something else. After 3 SYN retries, the browser shows a timeout error. The strange thing is: If I try to connect again after the timeout, the connection is established and further connects work as well! At least most of the time - sometimes it starts working not until the 2nd or 3rd timeout/reload. After some moments without new connections, lighty again refrains from accepting new connections... I have a huge installation of Apache webservers working well with the very same LVM-DR setup. The only notable difference between these two server types is that Apache uses traditional blocking I/O with forking processes and lighttpd uses non-blocking I/O with select()/epoll based multiplexing. While doing some investigation on this issue, I found a very similar problem reported on this list, titled "problems with ipvsadm - 3 seconds delay", dated from February 2008 (http://lists.graemef.net/pipermail/lvs-users/2008-February/020541.html). I think it describes the very same problem, especially with the problems occurring on Quad Core Xeons, which makes me think about a timing problem or race condition in kernel or glibc. Any ideas 'round here which may help me to track this issue down? Regards, Jan -- Psssst! Schon vom neuen GMX MultiMessenger gehört? Der kann`s mit allen: http://www.gmx.net/de/go/multimessenger _______________________________________________ Please read the documentation before posting - it's available at: http://www.linuxvirtualserver.org/ LinuxVirtualServer.org mailing list - [email protected] Send requests to [email protected] or go to http://lists.graemef.net/mailman/listinfo/lvs-users
