Hi all,<div><br></div><div>After turning on keepalives, we've been seeing one crash pretty consistently.</div><div>We're running nginx 1.1.5 and here is the backtrace :</div><div><br></div><div><div>(gdb) bt</div><div>

#0  ngx_write_chain_to_file (file=0x173dbd0, cl=0x0, offset=26779, pool=0x162b850) at src/os/unix/ngx_files.c:162</div><div>#1  0x000000000040ea3e in ngx_write_chain_to_temp_file (tf=0x173dbd0, chain=0x0) at src/core/ngx_file.c:35</div>

<div>#2  0x000000000041c534 in ngx_event_pipe_write_chain_to_temp_file (p=0x173d048) at src/event/ngx_event_pipe.c:771</div><div>#3  0x000000000041cd3d in ngx_event_pipe_read_upstream (p=0x173d048, do_write=0) at src/event/ngx_event_pipe.c:234</div>

<div>#4  ngx_event_pipe (p=0x173d048, do_write=0) at src/event/ngx_event_pipe.c:50</div><div>#5  0x000000000043e1b6 in ngx_http_upstream_process_upstream (r=0x1ae4bb0, u=0x1afb4f8) at src/http/ngx_http_upstream.c:2704</div>

<div>#6  0x000000000043e612 in ngx_http_upstream_handler (ev=0x689b) at src/http/ngx_http_upstream.c:936</div><div>#7  0x000000000041b1f6 in ngx_event_process_posted (cycle=<value optimized out>, posted=0x0) at src/event/ngx_event_posted.c:39</div>

<div>#8  0x000000000041b0c6 in ngx_process_events_and_timers (cycle=0x151bbf0) at src/event/ngx_event.c:272</div><div>#9  0x0000000000420bc3 in ngx_worker_process_cycle (cycle=0x151bbf0, data=<value optimized out>) at src/os/unix/ngx_process_cycle.c:801</div>

<div>#10 0x000000000041f4cc in ngx_spawn_process (cycle=0x151bbf0, proc=0x420aeb <ngx_worker_process_cycle>, data=<value optimized out>, name=0x470dc9 "worker process", respawn=5) at src/os/unix/ngx_process.c:196</div>

<div>#11 0x0000000000421359 in ngx_reap_children (cycle=0x151bbf0) at src/os/unix/ngx_process_cycle.c:617</div><div>#12 ngx_master_process_cycle (cycle=0x151bbf0) at src/os/unix/ngx_process_cycle.c:180</div><div>#13 0x000000000040700a in main (argc=<value optimized out>, argv=<value optimized out>) at src/core/nginx.c:405</div>

</div><div><br></div><div>It seems that p->in is NULL in ngx_event_pipe_write_chain_to_temp_file() but I can't figure out why.</div><div>It's using the proxy module as an upstream. </div><div><br></div><div>Let me know I could provide more info to help!</div>

<div><br></div><div>Matthieu.</div><div><br></div><div><br></div>