svn commit: r947258 - in /websites/staging/mahout/trunk/content: ./ users/environment/h2o-internals.html

[bu...@apache.org]

Author: buildbot
Date: Sun Apr 12 01:05:23 2015
New Revision: 947258

Log:
Staging update by buildbot for mahout

Modified:
    websites/staging/mahout/trunk/content/   (props changed)
    websites/staging/mahout/trunk/content/users/environment/h2o-internals.html

Propchange: websites/staging/mahout/trunk/content/
------------------------------------------------------------------------------
--- cms:source-revision (original)
+++ cms:source-revision Sun Apr 12 01:05:23 2015
@@ -1 +1 @@
-1672957
+1672958

Modified: websites/staging/mahout/trunk/content/users/environment/h2o-internals.html
==============================================================================
--- websites/staging/mahout/trunk/content/users/environment/h2o-internals.html (original)
+++ websites/staging/mahout/trunk/content/users/environment/h2o-internals.html Sun Apr 12 01:05:23 2015
@@ -256,14 +256,14 @@
   <div id="content-wrap" class="clearfix">
    <div id="main">
     <h1 id="introduction">Introduction</h1>
-<p>This document provides an overview of how the Mahout Scala DSL (distributed algebraic operators) is implemented over the H2O backend engine. The document is aimed at Mahout developers, to give a high level description of the design so that one can explore the code inside <code>h2o/</code> with some context.</p>
+<p>This document provides an overview of how the Mahout Samsara environment is implemented over the H2O backend engine. The document is aimed at Mahout developers, to give a high level description of the design so that one can explore the code inside <code>h2o/</code> with some context.</p>
 <h2 id="h2o-overview">H2O Overview</h2>
 <p>H2O is a distributed scalable machine learning system. Internal architecture of H2O has a distributed math engine (h2o-core) and a separate layer on top for algorithms and UI. The Mahout integration requires only the math engine (h2o-core).</p>
 <h2 id="h2o-data-model">H2O Data Model</h2>
 <p>The data model of the H2O math engine is a distributed columnar store (of primarily numbers, but also strings). A column of numbers is called a Vector, which is broken into Chunks (of a few thousand elements). Chunks are distributed across the cluster based on a deterministic hash. Therefore, any member of the cluster knows where a particular Chunk of a Vector is homed. Each Chunk is separately compressed in memory and elements are individually decompressed on the fly upon access with purely register operations (thereby achieving high memory throughput). An ordered set of similarly partitioned Vecs are composed into a Frame. A Frame is therefore a large two dimensional table of numbers. All elements of a logical row in the Frame are guaranteed to be homed in the same server of the cluster. Generally speaking, H2O works well on "tall skinny" data, i.e, lots of rows (100s of millions) and modest number of columns (10s of thousands).</p>
 <h2 id="mahout-drm">Mahout DRM</h2>
-<p>The Mahout DRM, or Distributed Row Matrix, is an abstraction for storing a large matrix of numbers in-memory in a cluster by distributing logical rows among servers. The DSL provides an abstract API on DRMs for backend engines to provide implementations of this API. Examples are the Spark and H2O backend engines. Each engine has it's own design of mapping the abstract API onto its data model and provides implementations for algebraic operators over that mapping.</p>
-<h2 id="h2o-dsl-engine">H2O DSL Engine</h2>
+<p>The Mahout DRM, or Distributed Row Matrix, is an abstraction for storing a large matrix of numbers in-memory in a cluster by distributing logical rows among servers. Mahout's scala DSL provides an abstract API on DRMs for backend engines to provide implementations of this API. Examples are the Spark and H2O backend engines. Each engine has it's own design of mapping the abstract API onto its data model and provides implementations for algebraic operators over that mapping.</p>
+<h2 id="h2o-environment-engine">H2O Environment Engine</h2>
 <p>The H2O backend implements the abstract DRM as an H2O Frame. Each logical column in the DRM is an H2O Vector. All elements of a logical DRM row are guaranteed to be homed on the same server. A set of rows stored on a server are presented as a read-only virtual in-core Matrix (i.e BlockMatrix) for the closure method in the <code>mapBlock(...)</code> API.</p>
 <p>H2O provides a flexible execution framework called <code>MRTask</code>. The <code>MRTask</code> framework typically executes over a Frame (or even a Vector), supports various types of map() methods, can optionally modify the Frame or Vector (though this never happens in the Mahout integration), and optionally create a new Vector or set of Vectors (to combine them into a new Frame, and consequently a new DRM).</p>
 <h2 id="source-layout">Source Layout</h2>