[IPython-dev] client connection in shared filesystem for a farm of machines

[Johann Cohen-Tanugi]

Hello,
I am using a farm of several machines, and I log in to it using ssh and 
a generic farm name, ending up on one specific machine depending on 
loads etc.... All the machines of the farm see the AFS filesystem, on 
which a json file was created when I fired ipcluster after a first login 
to the farm.
Then I start another terminal and log in again to the farm, ending up on 
another machine than the one the ipcluster is running on.
If I then do :
from IPython.parallel import Client
c = Client()

it hangs.... If I do:
c = 
Client('/u/ec/cohen/.config/ipython/profile_default/security/ipcontroller-client.json')
it returns :
---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
/a/wain006/g.glast.u54/cohen/IPYDEV/test_directory/<ipython-input-3-9325a79c5ee0> 
in <module>()
----> 1 c = 
Client('/u/ec/cohen/.config/ipython/profile_default/security/ipcontroller-client.json')

TypeError: __new__() takes exactly 1 argument (2 given)

so I guess the doc in 
http://ipython.org/ipython-doc/dev/parallel/parallel_intro.html#getting-started 
needs a patch.

Finally if I do :
c = 
Client(url_or_file='/afs/slac/u/ec/cohen/.config/ipython/profile_default/security/ipcontroller-client.json')
it also hangs, while on the same ipython session I can immediately check :
In [8]: ls -ltr 
/afs/slac/u/ec/cohen/.config/ipython/profile_default/security/ipcontroller-client.json
-rw------- 1 cohen ec 130 Jun 22 08:06 
/afs/slac/u/ec/cohen/.config/ipython/profile_default/security/ipcontroller-client.json

that indeed the JSON file is accessible via the AFS file sharing.


I checked that if I forced connecting to the same machine instead of 
using the generic farm name,
c=Client() immediately returns with the engines attached and I can 
proceed normally.

Thanks in advance for the help,
johann