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wavefront_master(1) Cooperative Computing Tools wavefront_master(1)

NAME

wavefront_master - executes Wavefront workflow in parallel on distributed systems

SYNOPSIS

wavefront [options] <command> <xsize> <ysize> <inputdata> <outputdata>

DESCRIPTION

wavefront_master computes a two dimensional recurrence relation. You provide a function F (<command>) that accepts the left (x), right (y), and diagonal (d) values and initial values (<inputdata>) for the edges of the matrix. The output matrix, whose size is determined by <xsize> and <ysize>, will be stored in a file specified by <outputdata>.

wavefront_master uses the Work Queue system to distribute tasks among processors. After starting wavefront_master, you must start a number of work_queue_worker(1) processes on remote machines. The workers will then connect back to the master process and begin executing tasks.

OPTIONS

 -h, --help
Show this help screen
 -v, --version
Show version string
Enable debugging for this subsystem. (Try -d all to start.)
Set the project name to <project>
Write debugging output to this file. By default, debugging is sent to stderr (":stderr"). You may specify logs to be sent to stdout (":stdout") instead.
Port number for queue master to listen on.
Priority. Higher the value, higher the priority.
Select port at random and write it to this file. (default is disabled)
 --work-queue-preferred-connection <connection>
Indicate preferred connection. Chose one of by_ip or by_hostname. (default is by_ip)

EXIT STATUS

On success, returns zero. On failure, returns non-zero.

EXAMPLES

Suppose you have a program named function that you want to use in the Wavefont workflow computation. The program function, when invoked as function a b c, should do some computations on files a, b and c and produce some output on the standard output.

Before running wavefront_master, you need to create a file, say input.data, that lists initial values of the matrix (values on the left and bottom edges), one per line:



 0	0	value.0.0


 0	1	value.0.1


 ...


 0	n	value.0.n


 1	0	value.1.0


 2	0	value.2.0


 ...


 n	0	value.n.0

To run a Wavefront workflow sequentially, start a single work_queue_worker(1) process in the background. Then, invoke wavefront_master. The following example computes a 10 by 10 Wavefront matrix:



 % work_queue_worker localhost 9123 &


 % wavefront_master function 10 10 input.data output.data

The framework will carry out the computations in the order of dependencies, and print the results one by one (note that the first two columns are X and Y indices in the resulting matrix) in the specified output file. Below is an example of what the output file - output.data would look like:



 1	1	value.1.1


 1	2	value.1.2


 1	3	value.1.3


 ...

To speed up the process, run more work_queue_worker(1) processes on other machines, or use condor_submit_workers(1) or sge_submit_workers(1) to start hundreds of workers in your local batch system.

The following is an example of adding more workers to execute a Wavefront workflow. Suppose your wavefront_master is running on a machine named barney.nd.edu. If you have access to login to other machines, you could simply start worker processes on each one, like this:



 % work_queue_worker barney.nd.edu 9123

If you have access to a batch system like Condor, you can submit multiple workers at once:



 % condor_submit_workers barney.nd.edu 9123 10


 Submitting job(s)..........


 Logging submit event(s)..........


 10 job(s) submitted to cluster 298.

COPYRIGHT

The Cooperative Computing Tools are Copyright (C) 2005-2019 The University of Notre Dame. This software is distributed under the GNU General Public License. See the file COPYING for details.

SEE ALSO

CCTools 8.0.0 DEVELOPMENT