[IPython-dev] Debugging parallel engines

[Dave Hirschfeld]

MinRK <benjaminrk <at> gmail.com> writes:

> 
> You can do this on an engine as well, you just have to tell the engine(s) 
to listen for connections by calling `parallel.bind_kernel()` on them
> 
> http://nbviewer.ipython.org/5672387
> 
> Is it possible to connect a qtconsole to a currently running parallel 
engine
> instance?
> Thanks,
> Dave


Brilliant, thanks - that's *extremely* useful for debugging!

%qtconsole doesn't appear to work on windows - is this a known issue?

>>> res = rc[0].execute("%qtconsole")
>>> res.display_outputs()
ERROR: Could not start qtconsole: ValueError('close_fds is not supported on 
Windows platforms if you redirect stdin/stdout/stderr',)
>>>

It's not a problem because when you call `bind_kernel` the engine tells you 
the name of the json file to connect to in the logs and you can then start a 
qtconsole from the command line with the --existing switch

2013-05-30 09:26:10.615 [IPEngineApp] Opening ports for direct connections 
as an IPython kernel
2013-05-30 09:26:10.638 [IPEngineApp] To connect another client to this 
kernel, use:
2013-05-30 09:26:10.638 [IPEngineApp]     --existing kernel-9248.json
To connect another client to this kernel, use:
    --existing kernel-9248.json


Thanks for your help!...

-Dave