I found a way that causes the 1.4.10 (and probably 1.4.11) releases to crash with a segfault. The message in /var/log/messages is
Mar 3 12:44:34 host kernel: haproxy[16392]: segfault at 0000000000000000 rip 0000000000000000 rsp 00007fff7402a9d8 error 14 host:~$ /usr/sbin/haproxy -vv HA-Proxy version 1.4.10 2010/11/28 Copyright 2000-2010 Willy Tarreau <[email protected]> Build options : TARGET = linux26 CPU = generic CC = gcc CFLAGS = -O2 -g -fno-strict-aliasing OPTIONS = USE_LINUX_TPROXY=1 USE_REGPARM=1 USE_PCRE=1 Default settings : maxconn = 2000, bufsize = 16384, maxrewrite = 8192, maxpollevents = 200 Encrypted password support via crypt(3): yes Available polling systems : sepoll : pref=400, test result OK epoll : pref=300, test result OK poll : pref=200, test result OK select : pref=150, test result OK Total: 4 (4 usable), will use sepoll. The segfault occurs if a server in disabled backend is put into maintenance mode using the socket. For example: backend foo disabled server 1.2.3.4 1.2.3.4 server 1.2.3.5 1.2.3.5 $> echo "disable server foo/1.2.3.4" | socat stdio /var/lib/haproxy/stats Unfortunately I had a script that would disable a particular server for all backends the server was in. The script didn't check that a backend wasn't already disabled and so crashed a production server. I've been able to reproduce this on other instances so I don't think it was a one-time coincidence. -Bryan
