Comment 11 for bug 509015

Revision history for this message
Vishal Vatsa (vvatsa) wrote : Re: [Bug 509015] Re: ipcluster does not start all the engines

Would you mind sending me a copy of your script.
Also, is the setup like:
ipcontroller is on windows and ipengines are on linux

-v

2010/1/19 Toby Burnett <email address hidden>:
> About ssh on windows, we use the cygwin version, but not in the cygwin bash shell.
> C:\Users\burnett>ssh -V
> OpenSSH_3.8.1p1, OpenSSL 0.9.7d 17 Mar 2004
>
> I tried a version of my script that starts an ipcontroller, then 16
> ipengines on each of the 4 machines. It I delay after the ipcontroller,
> I have the same problem: 2-3 engines don't get started per machine.
> However, a 100 ms delay in that loop that creates the engines works just
> fine.
>
> This seems inconsistent with an assertion about how the engines connect
> to a controller.
>
> --
> ipcluster does not start all the engines
> https://bugs.launchpad.net/bugs/509015
> You received this bug notification because you are a bug assignee.
>
> Status in IPython - Enhanced Interactive Python: New
>
> Bug description:
> As reported on the mailing list...
>
>
> ---------- Forwarded message ----------
> From: Toby Burnett <tburnett@EMAIL-REMOVED>
> Date: Sat, Jan 16, 2010 at 8:58 AM
> Subject: [IPython-user] ipcluster does not start all the engines
> To: "<email address hidden>" <email address hidden>
>
>
> Hi,
> I did not find any previous notes on this.
> I have a cluster of 4 machines, each with 8 hyperthreaded cores, so I can run 16 engines per machine, or 64 in all. It is amazingly easy and useful, thanks so much for providing this.
>
> However, when using ipcluster on one of these machines in ssh mode, with this clusterfile,
> send_furl = False
> engines = { 'tev1' : 16,
>           'tev2' : 16,
>           'tev3' : 16,
>           'tev4' : 16
> }
>
> I typically get about 50 engines to actually start. Since there seems to be no log file for ipcluster (in spite of code that seems like it should record which engines it tried to start), I can't send that. The ipcontroller log file looks fine, except for recording fewer than the 64 engines that I expected.
>
> I have an alternative, very klugy method that starts a controller, then executes 64 ssh commands to the respective machines to simply run ipengine. I found the same problem, which went away when I introduced a 1 second delay after each ssh call, which of course takes more than a minute to run, and leaves all those ssh processes running.
>
> So I suspect that the same thing would work in the loop in this method of ipcluster.SSHEngineSet
>
>   def _ssh_engine(self, hostname, count):
>       exec_engine = "ssh %s sh %s/%s-sshx.sh %s" % (
>           hostname, self.temp_dir,
>           os.environ['USER'], self.engine_command
>       )
>       cmds = exec_engine.split()
>       dlist = []
>       log.msg("about to start engines...")
>       for i in range(count):
>           log.msg('Starting engines: %s' % exec_engine)
>           d = getProcessOutput(cmds[0], cmds[1:], env=os.environ)
>           dlist.append(d)
>       return gatherBoth(dlist, consumeErrors=True)
>
> but that would be inelegant, given that the real problem is probably related to the controller not responding properly to multiple requests.
>
> Thanks for looking at this.
>
> --Toby Burnett
>
>
>