It's a fairly vanilla install of nginx (with the exception of the SPDY patch). We are seeing roughly 1 segfault every hour or so on each web server... I didn't generate a debugging log, because I wasn't sure how big something like that would be for an entire hour, but I can if needed.

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nginx -V
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nginx version: nginx/1.3.12
built by gcc 4.5.1 20101208 [gcc-4_5-branch revision 167585] (SUSE Linux)
TLS SNI support enabled
configure arguments: --prefix=/etc/nginx --sbin-path=/usr/sbin/nginx --pid-path=/var/run/nginx.pid --error-log-path=/usr/log/ngnix/error.log --http-log-path=/usr/log/ngnix/access.log --with-openssl=/home/software_source/openssl-1.0.1c --with-cc-opt='-I /usr/local/ssl/include' --with-ld-opt='-L /usr/local/ssl/lib' --without-http_proxy_module --without-http_ssi_module --with-http_ssl_module --with-http_stub_status_module --with-http_spdy_module


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backtrace from core dump:
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#0 0x00000000004514ea in ngx_http_spdy_send_output_queue (sc=0xd77610) at src/http/ngx_http_spdy.c:713
cl = <value optimized out>
c = 0x7fe9a5436f90
clcf = <value optimized out>
out = <value optimized out>
frame = 0xa250d0
fn = <value optimized out>
#1 0x00000000004520b2 in ngx_http_spdy_write_handler (wev=<value optimized out>) at src/http/ngx_http_spdy.c:644
rc = <value optimized out>
c = <value optimized out>
fc = <value optimized out>
ctx = <value optimized out>
r = <value optimized out>
stream = <value optimized out>
s = <value optimized out>
sn = <value optimized out>
sc = 0xd77610
#2 0x000000000041a5ba in ngx_event_process_posted (cycle=<value optimized out>, posted=0x854a88) at src/event/ngx_event_posted.c:40
ev = <value optimized out>
#3 0x000000000041a1d5 in ngx_process_events_and_timers (cycle=0x885a90) at src/event/ngx_event.c:276
flags = 3
timer = <value optimized out>
delta = 81
#4 0x0000000000420038 in ngx_worker_process_cycle (cycle=0x885a90, data=<value optimized out>) at src/os/unix/ngx_process_cycle.c:807
worker = <value optimized out>
i = <value optimized out>
c = <value optimized out>
#5 0x000000000041e9a3 in ngx_spawn_process (cycle=0x885a90, proc=0x41ff6c <ngx_worker_process_cycle>, data=0x2, name=0x59b51a "worker process", respawn=-3) at src/os/unix/ngx_process.c:198
on = 1
pid = 0
s = 2
#6 0x000000000041f5f6 in ngx_start_worker_processes (cycle=0x885a90, n=4, type=-3) at src/os/unix/ngx_process_cycle.c:362
i = <value optimized out>
ch = {command = 1, pid = 6348, slot = 1, fd = 19}
#7 0x00000000004206d1 in ngx_master_process_cycle (cycle=0x885a90) at src/os/unix/ngx_process_cycle.c:136
title = 0x973f74 "master process /usr/sbin/nginx"
p = <value optimized out>
size = 31
i = 1
n = <value optimized out>
sigio = <value optimized out>
set = {__val = {0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0}}
itv = {it_interval = {tv_sec = 0, tv_usec = 0}, it_value = {tv_sec = 0, tv_usec = 0}}
live = <value optimized out>
delay = <value optimized out>
ls = <value optimized out>
ccf = 0x0
#8 0x000000000040546c in main (argc=<value optimized out>, argv=<value optimized out>) at src/core/nginx.c:412
i = <value optimized out>
log = 0x84d7a0
cycle = 0x0
init_cycle = {conf_ctx = 0x0, pool = 0x884fa0, log = 0x84d7a0, new_log = {log_level = 0, file = 0x0, connection = 0, handler = 0, data = 0x0, action = 0x0}, files = 0x1, free_connections = 0x0, free_connection_n = 0, reusable_connections_queue = {
prev = 0x0, next = 0x0}, listening = {elts = 0x0, nelts = 0, size = 0, nalloc = 0, pool = 0x0}, paths = {elts = 0x0, nelts = 0, size = 0, nalloc = 1, pool = 0x0}, open_files = {last = 0x0, part = {elts = 0x0, nelts = 0, next = 0x0}, size = 0,
nalloc = 0, pool = 0x0}, shared_memory = {last = 0x0, part = {elts = 0x0, nelts = 0, next = 0x0}, size = 1, nalloc = 0, pool = 0x0}, connection_n = 0, files_n = 0, connections = 0x0, read_events = 0x0, write_events = 0x0, old_cycle = 0x0, conf_file = {
len = 0, data = 0x0}, conf_param = {len = 0, data = 0x0}, conf_prefix = {len = 1, data = 0x0}, prefix = {len = 0, data = 0x0}, lock_file = {len = 0, data = 0x0}, hostname = {len = 0, data = 0x0}}
ccf = <value optimized out>