Author: buildbot
Date: Fri Apr 3 23:14:51 2015
New Revision: 946256
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 Fri Apr 3 23:14:51 2015
@@ -1 +1 @@
-1671214
+1671216
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
Fri Apr 3 23:14:51 2015
@@ -256,7 +256,7 @@
<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>
-<h2 id="h2o-overview"><a href="http://h2o.ai/";>H2O</a> Overview</h2>
+<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>
@@ -267,22 +267,14 @@
<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>
<p>Within mahout.git, the top level directory, <code>h2o/</code> holds all the
source code related to the H2O backend engine. Part of the code (that
interfaces with the rest of the Mahout componenets) is in Scala, and part of
the code (that interfaces with h2o-core and implements algebraic operators) is
in Java. Here is a brief overview of what functionality can be found where
within <code>h2o/</code>.</p>
-<div class="codehilite"><pre><span class="n">h2o</span><span
class="o">/</span> <span class="o">-</span> <span class="n">top</span> <span
class="n">level</span> <span class="n">directory</span> <span
class="n">containing</span> <span class="n">all</span> <span
class="n">H2O</span> <span class="n">related</span> <span class="n">code</span>
-
-<span class="n">h2o</span><span class="o">/</span><span
class="n">src</span><span class="o">/</span><span class="n">main</span><span
class="o">/</span><span class="n">java</span><span class="o">/</span><span
class="n">org</span><span class="o">/</span><span class="n">apache</span><span
class="o">/</span><span class="n">mahout</span><span class="o">/</span><span
class="n">h2obindings</span><span class="o">/</span><span
class="n">ops</span><span class="o">/*</span><span class="p">.</span><span
class="n">java</span> <span class="o">-</span> <span class="n">Physical</span>
<span class="n">operator</span> <span class="n">code</span> <span
class="k">for</span> <span class="n">the</span> <span class="n">various</span>
<span class="n">DSL</span> <span class="n">algebra</span>
-
-<span class="n">h2o</span><span class="o">/</span><span
class="n">src</span><span class="o">/</span><span class="n">main</span><span
class="o">/</span><span class="n">java</span><span class="o">/</span><span
class="n">org</span><span class="o">/</span><span class="n">apache</span><span
class="o">/</span><span class="n">mahout</span><span class="o">/</span><span
class="n">h2obindings</span><span class="o">/</span><span
class="n">drm</span><span class="o">/*</span><span class="p">.</span><span
class="n">java</span> <span class="o">-</span> <span class="n">DRM</span> <span
class="n">backing</span> <span class="p">(</span><span class="n">onto</span>
<span class="n">Frame</span><span class="p">)</span> <span class="n">and</span>
<span class="n">Broadcast</span> <span class="n">implementation</span>
-
-<span class="n">h2o</span><span class="o">/</span><span
class="n">src</span><span class="o">/</span><span class="n">main</span><span
class="o">/</span><span class="n">java</span><span class="o">/</span><span
class="n">org</span><span class="o">/</span><span class="n">apache</span><span
class="o">/</span><span class="n">mahout</span><span class="o">/</span><span
class="n">h2obindings</span><span class="o">/</span><span
class="n">H2OHdfs</span><span class="p">.</span><span class="n">java</span>
<span class="o">-</span> <span class="n">Read</span> <span class="o">/</span>
<span class="n">Write</span> <span class="n">between</span> <span
class="n">DRM</span> <span class="p">(</span><span class="n">Frame</span><span
class="p">)</span> <span class="n">and</span> <span class="n">files</span>
<span class="n">on</span> <span class="n">HDFS</span>
-
-<span class="n">h2o</span><span class="o">/</span><span
class="n">src</span><span class="o">/</span><span class="n">main</span><span
class="o">/</span><span class="n">java</span><span class="o">/</span><span
class="n">org</span><span class="o">/</span><span class="n">apache</span><span
class="o">/</span><span class="n">mahout</span><span class="o">/</span><span
class="n">h2obindings</span><span class="o">/</span><span
class="n">H2OBlockMatrix</span><span class="p">.</span><span
class="n">java</span> <span class="o">-</span> <span class="n">A</span> <span
class="n">vertical</span> <span class="n">block</span> <span
class="n">matrix</span> <span class="n">of</span> <span class="n">DRM</span>
<span class="n">presented</span> <span class="n">as</span> <span
class="n">a</span> <span class="n">virtual</span> <span
class="n">copy</span><span class="o">-</span><span class="n">on</span><span
class="o">-</span><span class="n">write</span> <span class="n">in</span><span
class="o">-</span><span
class="n">core</span> <span class="n">Matrix</span><span class="p">.</span>
<span class="n">Used</span> <span class="n">in</span> <span
class="n">mapBlock</span><span class="p">()</span> <span class="n">API</span>
-
-<span class="n">h2o</span><span class="o">/</span><span
class="n">src</span><span class="o">/</span><span class="n">main</span><span
class="o">/</span><span class="n">java</span><span class="o">/</span><span
class="n">org</span><span class="o">/</span><span class="n">apache</span><span
class="o">/</span><span class="n">mahout</span><span class="o">/</span><span
class="n">h2obindings</span><span class="o">/</span><span
class="n">H2OHelper</span><span class="p">.</span><span class="n">java</span>
<span class="o">-</span> <span class="n">A</span> <span
class="n">collection</span> <span class="n">of</span> <span
class="n">various</span> <span class="n">functionality</span> <span
class="n">and</span> <span class="n">helpers</span><span class="p">.</span>
<span class="n">For</span> <span class="n">e</span><span
class="p">.</span><span class="n">g</span><span class="p">,</span> <span
class="n">convert</span> <span class="n">between</span> <span
class="n">in</span><span class="o">-</span><s
pan class="n">core</span> <span class="n">Matrix</span> <span
class="n">and</span> <span class="n">DRM</span><span class="p">,</span> <span
class="n">various</span> <span class="n">summary</span> <span
class="n">statistics</span> <span class="n">on</span> <span
class="n">DRM</span><span class="o">/</span><span class="n">Frame</span><span
class="p">.</span>
-
-<span class="n">h2o</span><span class="o">/</span><span
class="n">src</span><span class="o">/</span><span class="n">main</span><span
class="o">/</span><span class="n">scala</span><span class="o">/</span><span
class="n">org</span><span class="o">/</span><span class="n">apache</span><span
class="o">/</span><span class="n">mahout</span><span class="o">/</span><span
class="n">h2obindings</span><span class="o">/</span><span
class="n">H2OEngine</span><span class="p">.</span><span class="n">scala</span>
<span class="o">-</span> <span class="n">DSL</span> <span
class="n">operator</span> <span class="n">graph</span> <span
class="n">evaluator</span> <span class="n">and</span> <span
class="n">various</span> <span class="n">abstract</span> <span
class="n">API</span> <span class="n">implementations</span> <span
class="k">for</span> <span class="n">a</span> <span
class="n">distributed</span> <span class="n">engine</span>
-
-<span class="n">h2o</span><span class="o">/</span><span
class="n">src</span><span class="o">/</span><span class="n">main</span><span
class="o">/</span><span class="n">scala</span><span class="o">/</span><span
class="n">org</span><span class="o">/</span><span class="n">apache</span><span
class="o">/</span><span class="n">mahout</span><span class="o">/</span><span
class="n">h2obindings</span><span class="o">/*</span> <span class="o">-</span>
<span class="n">Various</span> <span class="n">abstract</span> <span
class="n">API</span> <span class="n">implementations</span> <span
class="p">(</span>"<span class="n">glue</span> <span
class="n">work</span>"<span class="p">)</span>
-</pre></div>
+<p>h2o/ - top level directory containing all H2O related code</p>
+<p>h2o/src/main/java/org/apache/mahout/h2obindings/ops/*.java - Physical
operator code for the various DSL algebra</p>
+<p>h2o/src/main/java/org/apache/mahout/h2obindings/drm/*.java - DRM backing
(onto Frame) and Broadcast implementation</p>
+<p>h2o/src/main/java/org/apache/mahout/h2obindings/H2OHdfs.java - Read / Write
between DRM (Frame) and files on HDFS</p>
+<p>h2o/src/main/java/org/apache/mahout/h2obindings/H2OBlockMatrix.java - A
vertical block matrix of DRM presented as a virtual copy-on-write in-core
Matrix. Used in mapBlock() API</p>
+<p>h2o/src/main/java/org/apache/mahout/h2obindings/H2OHelper.java - A
collection of various functionality and helpers. For e.g, convert between
in-core Matrix and DRM, various summary statistics on DRM/Frame.</p>
+<p>h2o/src/main/scala/org/apache/mahout/h2obindings/H2OEngine.scala - DSL
operator graph evaluator and various abstract API implementations for a
distributed engine</p>
+<p>h2o/src/main/scala/org/apache/mahout/h2obindings/* - Various abstract API
implementations ("glue work")</p>
</div>
</div>
</div>
