PVMD                  package:rpvm                  R Documentation

_V_i_t_u_r_a_l _M_a_c_h_i_n_e _C_o_n_t_r_o_l

_D_e_s_c_r_i_p_t_i_o_n:

     Start new pvm daemon, add or delete hosts and stop pvmd.

_U_s_a_g_e:

     .PVM.start.pvmd (hosts = "", block = T)
     .PVM.addhosts (hosts)
     .PVM.delhosts (hosts)
     .PVM.halt ()

_A_r_g_u_m_e_n_t_s:

   hosts: a character vector, arguments to pvmd

   block: logical, if true, block until startup of all hosts complete

_D_e_t_a_i_l_s:

     '.PVM.start.pvmd' starts a _pvmd3_ process, the master of a new
     virtual machine.  It returns as soon as the pvmd is started and
     ready for work.  If the 'block' parameter is nonzero and a
     hostfile is passed to the pvmd as a parameter, it returns when all
     hosts marked to start have been added.

     '.PVM.addhosts' takes a vector of host names and add them to the
     virtual machine.  The names should have the same syntax as lines
     of a pvmd hostfile (see man page for pvmd3): A hostname followed
     by options of the form xx=y.

     The status of hosts can be requested by the application using
     '.PVM.mstats' and '.PVM.config'.  If a host fails it will be
     automatically deleted from the configuration.  Using
     '.PVM.addhosts' a replacement host can be added by the
     application, however it is the responsibility of the application
     developer to make his application tolerant of host failure. 
     Another use of this feature would be to add more hosts as they
     become available, for example on a weekend, or if the application
     dynamically determines it could use more computational power.

     '.PVM.delhosts' deletes the computers pointed to in 'hosts' from
     the existing configuration of computers making up the virtual
     machine.  All PVM processes and the pvmd running on these
     computers are killed as the computer is deleted.

     If a host fails, the PVM system will continue to function and will
     automatically delete this host from the virtual machine.  An
     application can be notified of a host failure by calling
     '.PVM.notify'.  It is still the responsibility of the application
     developer to make his application tolerant of host failure.

     '.PVM.halt' shuts down the the entire PVM system including remote
     tasks, remote pvmds, the local tasks (including the calling task)
     and the local pvmd.  Note, when I did this, it also kills the
     current R session.

_V_a_l_u_e:

     '.PVM.start.pvmd' will return the result from '.PVM.config'.

     '.PVM.halt' returns 'TRUE' if successful.

     '.PVM.addhosts' returns a vector of host ids that has been
     successfully added to the virtual machine.

     '.PVM.delhosts' returns a vector of status codes for each hosts
     successfulled removed from the virtual machine.

_A_u_t_h_o_r(_s):

     Na (Michael) Li nali@umn.edu and A.J. Rossini
     rossini@u.washington.edu

_R_e_f_e_r_e_n_c_e_s:

     PVM documentation

_E_x_a_m_p_l_e_s:

     # start a new virtual machine on local machine 
     ## Not run: 
     .PVM.start.pvmd ()
     # add two more hosts to it
     .PVM.addhosts ("sparky",
                    "thud.cs.utk.edu  ep=$R_LIBS/rpvm/")
     # do some work ...
     # finished with one machine
     .PVM.delhosts ("thud.cs.utk.edu")
     # do some other work ...
     # finished with pvm
     .PVM.halt ()
     ## End(Not run)

