parallel python not discovering worker nodes

Question

I am trying to implement a basic pp example as shown below (SCRIPT1).

import pp

ppservers = ("*",)  # autodiscovery mode on!

# create the job server
job_server = pp.Server(ppservers=ppservers)

for computer, cpu_count in job_server.get_active_nodes().iteritems():
    print "Found {} with CPU count {}!".format(computer, cpu_count)

Environment Details
OS : windows10
python version : 2.7 (on machine 1 and machine 2)
machine1 IP : 192.168.1.4
machine2 IP : 192.168.56.1

Steps followed till now :

1. machine1 and machine2 are connected in same network using wifi
2. SCRIPT1 is placed on machine1 (machine1 is job server)

3. installed pp in machine2(worker node) and started server on machine2 (port 60000) using

    python ppserver.py -a
   

4. triggered SCRIPT1 on machine1, machine 1 output is as shown below

Found local with CPU count 8!

But output at step4 is expected to also detect machine 2 and show output as

Found 192.168.56.1:60000 with CPU count 2!
Found local with CPU count 4!

A newbie to parrallel computing, how do i debug this ? Appreciate any kinda pointers for this.

Answer 1

Firewall and virtualBox was the issue.

Steps followed to get to the fix:

1. ping xxx.xxx.x.x. (machine1 IP)
2. run ppserver on same machine1 and see if jobserver can list the same machine1 as a worker node

if 1 and 2 is the issue, it is mostly caused by firewall, in this case add an inbound rule for the required port and continue.