[Pgpool-general] seemingly hung pgpool process consuming 100% CPU

[Lonni J Friedman]

No one else has experienced this or has suggestions how to debug it?

On Wed, Sep 7, 2011 at 12:49 PM, Lonni J Friedman <netllama at gmail.com> wrote:
> Greetings,
> I'm running pgpool-3.0.4 on a Linux-x86_64 server serving as a load
> balancer for a three server postgresql-9.0.4 cluster (1 master, 2
> standby).  I'm seeing strange behavior where a single pgpool process
> seems to hang after some period of time, and then consume 100% of the
> CPU.  I've seen this behavior happen twice since last Friday (when
> pgpool was brought online in my production environment).  At the
> moment the current hung process looks like this in 'ps auxww' output:
>
> postgres 19838 98.7  0.0  68856  2904 ?        R    Sep06 1027:36
> pgpool: lfriedman nightly 10.31.45.20(58277) idle
>
>
> In top, I see:
>  PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND
> 19838 postgres  20   0 68856 2904 1072 R 100.0  0.0   1027:29 pgpool
>
>
> When to connect to the process with strace, there is no output, so I'm
> guessing the process is stuck spinning somewhere:
> # strace -p 19838
> Process 19838 attached - interrupt to quit
> ...
> ^CProcess 19838 detached
>
> One thing that i'm certain of is that the client IP (10.31.45.20)
> associated with the hung process has rebooted at least once since that
> process was spawned.  So pgpool seems to be in some confused state, as
> the client definitely severed the connection already.  I checked the
> pgpool log and there are no explicit references to PID 19838.  I'm at
> a loss how to debug this further, but clearly something is wrong
> somewhere, and this isn't normal/expected behavior.
>
> Help?!
>
> thanks