[Condor-users] Flocking - remote nodes matching, but not executing

["Peter Myerscough-Jackopson" <peter.myerscough-jackopson@xxxxxxxxxx>]

Dear all,

 

I am having a problem with joining two pools via flocking, and I suspect it is mainly my assumptions that are wrong.

 

Background

--------------------------

 

Pool A has 10 machines

Pool B has 10 machines

All machines are running WinXP 64-bit on private networks without domain controllers.

The cluster heads on pool A and B are connected via a VPN, but none of the other nodes of each cluster are connected, nor is IP traffic forwarded.

 

I am running these pools in collaboration with someone else and I don't have direct access to pool B.

 

To join the two pools together both master(cluster heads) have BIND_ALL_INTERFACES = true so that they can operate on their internal network interface, and the VPN interface.

 

We have also added the name of the opposing pool's cluster head into our "hosts" file eg. 192.168.1.10 clusterhead_A

 

We have then added that name (not the ip address) to the condor_config file in the condor FLOCK_TO and FLOCK_FROM macros.

 

Our HOSTALLOW_READ and HOSTALLOW_WRITE are both *, which I know is bad, but the clusters are behind firewalls and VPNs and so only accessible by trusted parties. I was hoping to reduce the number of hoops flocking had to jump through and hope to bring this back up to some more secure settings.

 

I can run "condor_q -name clusterhead_A"  and see the opposing pools queue, but if I use the IP address, ie "condor_q -name 192.168.1.15" I get the error message:

"Error: Collector has no record of schedd/submitter"

 

"condor_q -global" also successfully returns the queue from the other pool.

 

I have not changed the NO_DNS macro nor the DEFAULT_DOMAIN_NAME macro in the condor_config file, both are commented out. If I do this and run condor_reconfig, then I get the following error message :

 

ERROR "gethostname failed, errno = 0" at line 266 in file ..\src\condor_c++_util\my_hostname.C

 

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The problem I get is as the subject line reads, and as you can see I've tried a few things.

 

What should I do to get condor flocking working such that jobs migrate and run on the other pool, without requiring a direct connection from my head to their execute nodes?

 

I was under the impression that jobs would migrate to the opposing pool's queue and then be submitted and managed by the opposing pool with the results being passed back. Am I wrong about this?

 

From my log files I can see my cluster head is trying to directly connect to the remote cluster's nodes, which it can't do. It is also seeming to have trouble connecting to itself on its VPN IP address even though I have BIND_ALL_INTERFACE=true.

 

If anyone has any ideas/solutions please do reply,

 

Peter

 

Ps. I can ping the remote cluster head across the VPN and also the VPN IP address of my own machine.

 

Dr Peter Myerscough-Jackopson
Engineer, MAC Ltd

phone: +44 (0) 23 8076 7808  fax: +44 (0) 23 8076 0602
email: peter.myerscough-jackopson@xxxxxxxxxx  web: www.macltd.com

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