############################################################################### # * # * # * # * # * # * # * # * # * # * # * # * # * # * # * # * # * # * # * # ############################################################################### This document describes MCE version 1.516 Many-core Engine (MCE) for Perl helps enable a new level of performance by maximizing all available cores. MCE spawns a pool of workers and therefore does not fork a new process per each element of data. Instead, MCE follows a bank queuing model. Imagine the line being the data and bank-tellers the parallel workers. MCE enhances that model by adding the ability to chunk the next n elements from the input stream to the next available worker. Both chunking and input data are optional in MCE. One may simply use MCE to have many workers run in parallel. MCE uses domain sockets for IPC versus pipes. One day, a physical box will have hundreds of cores. MCE can spawn 960 workers (via fork) for ulimit re- porting 1024 allowed for max user processes. Other parallel implementations using pipes cannot do this (only about half of ulimit -u). Use Cases for MCE. 1. Both forking and threading are supported. Workers are children by default (via fork). Including threads in your script will have workers spawn as threads unless use_threads => 0 is specified. 2. MCE can be used to process a single "large" file or process many "small" files in parallel. Performance against a single file is as fast as MMAP IO when specifying use_slurpio => 1. 3. MCE iterates over input data in chunks. Workers can be spawned prior to creating or obtaining data. MCE is a chunking engine. It does not divide the input equally by the number of workers. Instead, it chunks from start till end. input_data => '/path/to/file', ## Scalar is treated as a file input_data => \$scalar, ## Treated like a memory-based file input_data => \@array, ## A reference to an array input_data => \*FileHandle, ## Process a FH in parallel input_data => \&iterator, ## A reference to an iterator Think of input data as the highway. Now think of the automobile as being MCE. Data can be larger than physical memory on the box. The chunking nature makes this possible. 4. If all you need is a numeric iterator, MCE can iterate over a sequence of numbers mathematically. This too can be chunked by specifying chunk size. sequence => { begin => 1, end => 100, step => 2 }, chunk_size => 20, ## Worker receives the next 20 sequences Look at the examples included with MCE. The foreach.pl example is very communication intensive whereas forchunk.pl requires much less overhead. foreach.pl, forchunk.pl, and forseq.pl 5. For another example, a worker receives up to 600 host names or IPs per chunk. The worker uses SNMP and an AnyEvent library. Imagine having millions of hosts to process. One simply cannot create millions of connections all at once. Chunking makes this trivial to do. Take MCE for a spin. ############################################################################### # * # * # * # * # * # * # * # * # * # * # * # * # * # * # * # * # * # * # * # ############################################################################### INSTALLATION To install this module type the following: perl Makefile.PL make make test make install DEPENDENCIES This module requires Perl 5.8.0 or later. By default, MCE does forking (spawns child processes). MCE also supports threads via 2 threading libraries. The use of threads in MCE requires that you include threads support prior to loading MCE. use threads; use forks; use threads::shared; (or) use forks::shared; use MCE; use MCE; This module requires these other modules and libraries: Fcntl Socket Storable 2.04 or later File::Path Test::More 0.45 or later (for testing) COPYRIGHT AND LICENCE Copyright (C) 2012-2014 by Mario E. Roy This program is free software; you can redistribute it and/or modify it under the terms of either: the GNU General Public License as published by the Free Software Foundation; or the Artistic License. See L for more information. USAGE The source is hosted at http://code.google.com/p/many-core-engine-perl/ https://metacpan.org/module/MCE::Signal https://metacpan.org/module/MCE ############################################################################### # * # * # * # * # * # * # * # * # * # * # * # * # * # * # * # * # * # * # * # ############################################################################### Enjoy MCE !!! - Mario