pool(3erl)						     Erlang Module Definition							pool(3erl)

NAME

       pool - Load Distribution Facility

DESCRIPTION

       pool  can  be used to run a set of Erlang nodes as a pool of computational processors. It is organized as a master and a set of slave nodes
       and includes the following features:

	 * The slave nodes send regular reports to the master about their current load.

	 * Queries can be sent to the master to determine which node will have the least load.

       The BIF statistics(run_queue) is used for estimating future loads. It returns the length of the queue of ready  to  run	processes  in  the
       Erlang runtime system.

       The slave nodes are started with the slave module. This effects, tty IO, file IO, and code loading.

       If the master node fails, the entire pool will exit.

EXPORTS

       start(Name) ->
       start(Name, Args) -> Nodes

	      Types  Name = atom()
		     Args = string()
		     Nodes = [node()]

	      Starts  a  new pool. The file .hosts.erlang is read to find host names where the pool nodes can be started. See section Files below.
	      The start-up procedure fails if the file is not found.

	      The slave nodes are started with slave:start/2,3 , passing along Name and, if provided, Args . Name is used as the first part of the
	      node names, Args is used to specify command line arguments. See slave(3erl) .

	      Access rights must be set so that all nodes in the pool have the authority to access each other.

	      The function is synchronous and all the nodes, as well as all the system servers, are running when it returns a value.

       attach(Node) -> already_attached | attached

	      Types  Node = node()

	      This function ensures that a pool master is running and includes Node in the pool master's pool of nodes.

       stop() -> stopped

	      Stops the pool and kills all the slave nodes.

       get_nodes() -> Nodes

	      Types  Nodes = [node()]

	      Returns a list of the current member nodes of the pool.

       pspawn(Mod, Fun, Args) -> pid()

	      Types  Mod = Fun = atom()
		     Args = [term()]

	      Spawns a process on the pool node which is expected to have the lowest future load.

       pspawn_link(Mod, Fun, Args) -> pid()

	      Types  Mod = Fun = atom()
		     Args = [term()]

	      Spawn links a process on the pool node which is expected to have the lowest future load.

       get_node() -> node()

	      Returns the node with the expected lowest future load.

FILES

       .hosts.erlang is used to pick hosts where nodes can be started. See net_adm(3erl) for information about format and location of this file.

       $HOME/.erlang.slave.out.HOST  is  used  for  all additional IO that may come from the slave nodes on standard IO. If the start-up procedure
       does not work, this file may indicate the reason.

Ericsson AB							   stdlib 1.17.3							pool(3erl)