sleigh                  package:nws                  R Documentation

_C_l_a_s_s "_s_l_e_i_g_h"

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

     Represents a collection of R processes used to execute tasks.

     The sleigh allows R functions to be executed in parallel using the
     'eachElem' and  'eachWorker' methods.

     The sleigh workers are started when the sleigh object is
     constructed.  When tasks are submitted to the sleigh, using the
     'eachWorker' and 'eachElem' methods, the workers execute the tasks
     and return the results.  When the 'stopSleigh' method is called,
     the workers are stopped.

     A given R program can create multiple sleigh objects, each of
     which will have its own set of workers.  This can be useful if
     tasks have different requirements.  For example, you could create
     a Linux sleigh and a Windows sleigh, and submit Windows-specific
     tasks only to your Windows sleigh.

_O_b_j_e_c_t_s _f_r_o_m _t_h_e _C_l_a_s_s:

     Objects can be created by calls of the form 
      'sleigh(...)' 
      or 
      'new("sleigh",...)'
      where '...' can be one or more of the following named arguments:

     '_n_o_d_e_L_i_s_t': a list of hosts on which workers will be created. 
          This argument is ignored when 'launch='local''.  The default
          value is 'c('localhost', 'localhost', 'localhost')'.

     '_w_o_r_k_e_r_C_o_u_n_t': number of workers that will be created. This
          argument is only relevant when 'launch='local''.  The default
          value is 3.

     '_l_a_u_n_c_h': method to launch remote workers.  This can be set to the
          strings ''local'' (the default) or ''web'', or to a function
          object.  

          The function is called once for each worker listed in
          'nodeList'.  It  is passed two arguments: a name from
          'nodeList', and an  environment object that was constructed
          by merging 'defaultSleighOptions'  with the arguments that
          were passed to the sleigh constructor.  The  function should
          return a character vector, where the first element is the 
          command to execute, and the subsequent elements are the
          command arguments.   For example, the function could return
          the vector  'c('ssh', '-f', 'host')', where ''host'' is the
          first  argument to the launch function.  This  isn't the
          complete command to be executed; it's the 'remote execution' 
          portion of the command. The sleigh constructor will add the
          rest of the command based on the 'scriptExec' argument.  Note
          that the command is expected to return after launching the
          worker.  That is why the ssh -f option is used in the
          example.


     '_n_w_s_H_o_s_t': host name of the netWorkSpaces server. Default is the
          machine where sleigh starts up.

     '_n_w_s_P_o_r_t': port number of the netWorkSpaces server. Default is 
          8765.

     '_s_c_r_i_p_t_E_x_e_c': command to execute worker script.  Default uses
          'scriptcmd' function on Windows, and uses 'envcmd' function
          on  other platforms.

     '_s_c_r_i_p_t_D_i_r': location of the sleigh worker script. Default is the 
          bin directory under the nws package location. If library
          cannot be found, then use current working directory. 

     '_s_c_r_i_p_t_N_a_m_e': worker script file name. Default is 
          'RNWSSleighWorker.py' on Windows, and 'RNWSSleighWorker.sh'
          on other platforms.

     '_w_o_r_k_i_n_g_D_i_r': worker's working directory. Default is  master's
          current working directory.

     '_l_o_g_D_i_r': location where log files will be stored. Default is 
          'NULL'.

     '_o_u_t_f_i_l_e': remote workers' standard errors will be redirected to 
          this file. Default is 'NULL'.

     '_w_s_N_a_m_e_T_e_m_p_l_a_t_e': template name to create sleigh workspace. 
           Default is ''sleigh_ride_%010d''.

     '_u_s_e_r': user name used for remote execution.  Default is  'NULL'.

     '_v_e_r_b_o_s_e': a logical value indicating whether to print out debug
          messages. Default is 'FALSE'.

_M_e_t_h_o_d_s:


     _i_n_i_t_i_a_l_i_z_e 'signature(.Object = "sleigh")': sleigh class
          constructor.

     _e_a_c_h_E_l_e_m 'signature(.Object = "sleigh")': evaluate the given
          function with multiple argument sets using the workers in
          sleigh.

     _e_a_c_h_W_o_r_k_e_r 'signature(.Object = "sleigh")': evaluate the given
          function exactly once for each worker in sleigh.

     _r_a_n_k_C_o_u_n_t 'signature(.Object = "sleigh")': get sleigh's rankCount.

     _s_t_a_t_u_s 'signature(.Object = "sleigh")': return the status of the
          sleigh.

     _s_t_o_p_S_l_e_i_g_h 'signature(.Object = "sleigh")': shut down workers and
          remove sleigh workspace.

     _w_o_r_k_e_r_C_o_u_n_t 'signature(.Object = "sleigh")': get number of workers
          started in sleigh.

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

     There are six different standard launch types (''local'',
     'sshcmd',  'rshcmd', 'lsfcmd', 'sshforwardcmd', and ''web'') to 
     tailor the client's working environment.  This is done by setting
     launch variable to a function ('sshcmd', 'rshcmd', 
     'sshforwardcmd' or 'lsfcmd') or a string ('local' and 'web').  See
     the examples section.

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

     ## Not run: 
     # Default option: create three sleigh workers on local host:
     s <- sleigh()
     # which is equivalent to:
     s <- sleigh(launch='local')

     # Create sleigh workers on multiple machines using SSH:
     s <- sleigh(nodeList=c('n1', 'n2', 'n3'), launch=sshcmd)

     # Use the LSF bsub command to launch ten workers:
     s <- sleigh(nodeList=rep('fake', 10), launch=lsfcmd)

     # Use web launch:
     s <- sleigh(launch='web')
     ## End(Not run)

