Re: [naviserver-devel] ns_proxy hang

[David O. <da...@qc...>]

Not sure if this helps you - it may be entirely expected behaviour, but I
attached gbp to the nsproxy process and got a backtrace from the 2 test
cases I mentioned, immediately after the "ns_proxy eval...".

In the case with no hang the nsproxy process is waiting in RecvBuf:

#0  0x00007ffff6593250 in __libc_readv (fd=6,
vector=vector@entry=0x7fffffffe8a0,
count=count@entry=2)
    at ../sysdeps/unix/sysv/linux/readv.c:54
#1  0x00007ffff7bd717f in RecvBuf (slavePtr=0x7fffffffe930, ms=-1,
dsPtr=0x7fffffffe970) at nsproxylib.c:1319
#2  0x00007ffff7bd6391 in Ns_ProxyMain (argc=47, argv=0x7fffffffea50,
init=0x7fffffffe970) at nsproxylib.c:578
#3  0x00007ffff64d3b45 in __libc_start_main (main=0x400730 <main>, argc=4,
argv=0x7fffffffec48, init=<optimized out>, fini=<optimized out>,
    rtld_fini=<optimized out>, stack_end=0x7fffffffec38) at libc-start.c:287
#4  0x0000000000400765 in _start ()


The case which hangs, the nsproxy process is still waiting in SendBuf after
the "ns_proxy eval..." ends:


#0  0x00007ffff65932f0 in __libc_writev (fd=7,
vector=vector@entry=0x7fffffffe8b0,
count=count@entry=2)
    at ../sysdeps/unix/sysv/linux/writev.c:54
#1  0x00007ffff7bd6fcc in SendBuf (slavePtr=0x7fffffffe930, ms=-1,
dsPtr=<optimized out>) at nsproxylib.c:1245
#2  0x00007ffff7bd6365 in Ns_ProxyMain (argc=47, argv=0x7fffffffea50,
init=0x7fffffffe970) at nsproxylib.c:613
#3  0x00007ffff64d3b45 in __libc_start_main (main=0x400730 <main>, argc=4,
argv=0x7fffffffec48, init=<optimized out>, fini=<optimized out>,
    rtld_fini=<optimized out>, stack_end=0x7fffffffec38) at libc-start.c:287
#4  0x0000000000400765 in _start ()




On 10 May 2017 at 15:27, Gustaf Neumann <ne...@wu...> wrote:

> I'll look at it at the weekend - unless someone else can fix this before
> this.
>
> -g
> Am 10.05.17 um 16:00 schrieb David Osborne:
>
>  Increasing waittimeout doesn't seem to have any effect on this problem.
>
> I have backtraces of all threads at the point of the hang here:
> https://gist.github.com/davidqc/ebee38528b0a40a0b8d028981ad933e6
>
> Thread 19 I think is the culprit:
>
> Thread 19 (Thread 0x7fffaaffd700 (LWP 17652)):
> #0  0x00007ffff6322b89 in __libc_waitpid (pid=pid@entry=17651, stat_loc=stat_loc@entry=0x7fffaaffcde4, options=options@entry=0)
>     at ../sysdeps/unix/sysv/linux/waitpid.c:40
> #1  0x00007ffff7b5aa4c in Ns_WaitForProcess (pid=17651, exitcodePtr=0x0) at exec.c:178
> #2  0x00007ffff1b68615 in ReaperThread (UNUSED_arg=0x44f3) at nsproxylib.c:2935
> #3  0x00007ffff74b886d in NsThreadMain (arg=<optimized out>) at thread.c:232
> #4  0x00007ffff74b98a9 in ThreadMain (arg=<optimized out>) at pthread.c:830
> #5  0x00007ffff5e500a4 in start_thread (arg=0x7fffaaffd700) at pthread_create.c:309
> #6  0x00007ffff635162d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:111
>
>