
dispynetrelay
*************

dispynetrelay relays information about nodes on its network to dispy
scheduler(s).

If dispy scheduler and nodes are on same network, dispynetrelay is not
needed. If they are not, then there are two choices to use nodes on a
different network:

* When cluster is created with dispy, 'nodes' option must specify
  all the nodes (either IP addresses or host names) explicitly. This
  can be cumbersome if there are many nodes on different network(s).

* dispynetrelay is running on one node per network. In this case,
  dispynetrelay recognizes nodes on its network and relays that
  information to dispy scheduler. In this case, 'nodes' option to
  dispy client need to specify only the node(s) running dispynetrelay
  - all the nodes in that network can then be used by dispy. Note that
  'nodes' option is also used to filter matching nodes, so '*' may be
  added to the 'nodes' option to use all nodes.

Below are various options to invoking dispynetrelay:

* "--ip_addr addr" directs dispynetrelay to use given *addr* for
  communication, instead of the IP address associated with the host
  name.

* "--scheduler_node addr" sets dispynetrelay to direct nodes on its
  network to handshake with scheduler running at *addr*. If this
  option is not used, the IP address where dispynetrelay is running
  should be added to the 'nodes' argument when creating cluster (with
  JobCluster or SharedJobCluster).

* "--scheduler_port n" directs dispynetrelay to communicate with
  scheduler with given port *n* instead of default port 51349.

* "--node_port n" directs dispynetrelay to communicate with nodes in
  its network with port *n* instead of default port 51348.

* "-d" enables debug messages that show trace of execution. This may
  not be very useful to end users.
