[mpich-discuss] Race condition when accessing ~/.smpd during startup

[Jayesh Krishna]

 Hi,
  Please set the environment variable "SMPD_OPTION_NO_DYNAMIC_HOSTS" to 1
before starting smpd to prevent smpd from updating the dynamic_hosts in
smpd config file. 
  Let us know if it works for you.

(PS: As you mentioned in your email there is a race condition when
updating dynamic hosts in the smpd config file - this is not handled
correctly in the current code base. We set the above environment variable
in our nightly tests.)

Regards,
Jayesh

-----Original Message-----
From: mpich-discuss-bounces at mcs.anl.gov
[mailto:mpich-discuss-bounces at mcs.anl.gov] On Behalf Of Reuti
Sent: Tuesday, November 25, 2008 6:38 AM
To: mpich-discuss at mcs.anl.gov
Subject: [mpich-discuss] Race condition when accessing ~/.smpd during
startup

Hi,

to implement  a daemon based smpd startup method for MPICH2 (1.0.8) I use
a loop across all elected machines which a chosen port. The shutdown takes
the same list in reverse order. I.e. the daemon on the master node of the
parallel job is shutdown of last, so that for a shutdown no ssh or alike
is necessary as I use "smpd -port $port - shutdown $host".

This works fine, but from time to time I see a message in the logfile of
the script: "Please specify an authentication passphrase for this
smpd: Would you like to save this passphrase in '/home/ reuti/.smpd'?",
either during startup or shutdown of the daemons.  
Well, there is of course a passphrase in ~/.smpd.

I put now a "sleep 1" in the loops and this seems to avoid the problem.

As the dynamic_hosts="node001 node002" are also memorized in ~/.smpd:  
can it be a race condition, when the daemons are started/shutdown too
fast? Can the modification of this file be switched off?

-- Reuti
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.mcs.anl.gov/pipermail/mpich-discuss/attachments/20081125/a4831fcd/attachment.htm>