accumulo-commits mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From build...@apache.org
Subject svn commit: r814264 - in /websites/staging/accumulo/trunk/content: ./ glossary.html
Date Tue, 24 Apr 2012 18:48:16 GMT
Author: buildbot
Date: Tue Apr 24 18:48:15 2012
New Revision: 814264

Log:
Staging update by buildbot for accumulo

Modified:
    websites/staging/accumulo/trunk/content/   (props changed)
    websites/staging/accumulo/trunk/content/glossary.html

Propchange: websites/staging/accumulo/trunk/content/
------------------------------------------------------------------------------
--- cms:source-revision (original)
+++ cms:source-revision Tue Apr 24 18:48:15 2012
@@ -1 +1 @@
-1329882
+1329933

Modified: websites/staging/accumulo/trunk/content/glossary.html
==============================================================================
--- websites/staging/accumulo/trunk/content/glossary.html (original)
+++ websites/staging/accumulo/trunk/content/glossary.html Tue Apr 24 18:48:15 2012
@@ -89,25 +89,31 @@
   <div id="content">
     <h1 class="title">Apache Accumulo Glossary</h1>
     <ul>
-<li><strong>authorizations</strong> - </li>
-<li><strong>column</strong> - </li>
-<li><strong>column family</strong> - </li>
-<li><strong>column qualifier</strong> - </li>
-<li><strong>column visibility</strong> -</li>
-<li><strong>key</strong> - </li>
-<li><strong>iterator</strong> - </li>
-<li><strong>iterator scopes</strong> - </li>
-<li><strong>log-structured merge-tree</strong> - </li>
-<li><strong>major compaction</strong> - </li>
+<li><strong>authorizations</strong> - a set of strings associated with
a user or with a particular scan that will be used to determine which key/value pairs are
visible to the user.</li>
+<li><strong>cell</strong> - a set of key/value pairs whose keys differ
only in timestamp.</li>
+<li><strong>column</strong> - the portion of the key that sorts after the
row and is divided into family, qualifier, and visibility.</li>
+<li><strong>column family</strong> - the portion of the key that sorts
second and controls locality groups, the row/column hybrid nature of accumulo.</li>
+<li><strong>column qualifier</strong> - the portion of the key that sorts
third and provides additional key uniqueness.</li>
+<li><strong>column visibility</strong> - the portion of the key that sorts
fourth and controls user access to individual key/value pairs. Visibilities are boolean AND
(&amp;) and OR (|) combinations of authorization strings with parentheses required to
determine ordering, e.g. (AB&amp;C)|DEF.</li>
+<li><strong>iterator</strong> - a mechanism for modifying tablet-local
portions of the key/value space. Iterators are used for standard administrative tasks as well
as for custom processing.</li>
+<li><strong>iterator priority</strong> - an iterator must be configured
with a particular scope and priority.  When a tablet server enters that scope, it will instantiate
iterators in priority order starting from the smallest priority and ending with the largest,
and apply each to the data read before rewriting the data or sending the data to the user.</li>
+<li><strong>iterator scopes</strong> - the possible scopes for iterators
are where the tablet server is already reading and/or writing data: minor compaction / flush
time (<em>minc</em> scope), major compaction / file merging time (<em>majc</em>
scope), and query time (<em>scan</em> scope)</li>
+<li><strong>gc</strong> - </li>
+<li><strong>key</strong> - the key into the distributed sorted map which
is accumulo.  The key is subdivided into row, column, and timestamp.  The column is further
divided into  family, qualifier, and visibility.</li>
+<li><strong>locality group</strong> - a set of column families that will
be grouped together on disk.  With no locality groups configured, data is stored on disk in
row order.  If each column family were configured to be its own locality group, the data for
each column would be stored separately, in row order.  Configuring sets of columns into locality
groups is a compromise between the two approaches and will improve performance when multiple
columns are accessed in the same scan.</li>
+<li><strong>log-structured merge-tree</strong> - the sorting / flushing
/ merging scheme on which BigTable's design is based.</li>
+<li><strong>logger</strong> - </li>
+<li><strong>major compaction</strong> - merging multiple files into a single
file.  If all of a tablet's files are merged into a single file, it is called a <em>full
major compaction</em>.</li>
 <li><strong>master</strong> - </li>
-<li><strong>minor compaction</strong> - </li>
-<li><strong>permissions</strong> - </li>
-<li><strong>row</strong> - </li>
-<li><strong>scan</strong> -</li>
-<li><strong>tablet</strong> - a contiguous key range; the unit of work
for a tablet server</li>
-<li><strong>tablet server</strong> - </li>
-<li><strong>timestamp</strong> - </li>
-<li><strong>value</strong> - </li>
+<li><strong>minor compaction</strong> - flushing data from memory to disk.
 Usually this creates a new file for a tablet, but if the memory flushed is merge-sorted in
with data from an existing file (replacing that file), it is called a <em>merging minor
compaction</em>.</li>
+<li><strong>monitor</strong> -</li>
+<li><strong>permissions</strong> - administrative abilities that must be
given to a user such as creating tables or users and changing permissions or configuration
parameters.</li>
+<li><strong>row</strong> - the portion of the key that is controls atomicity.
 Keys with the same row are guaranteed to remain on a single tablet hosted by a single tablet
server, therefore multiple key/value pairs can be added to or removed from a row at the same
time. The row is used for the primary sorting of the key.</li>
+<li><strong>scan</strong> - reading a range of key/value pairs.</li>
+<li><strong>tablet</strong> - a contiguous key range; the unit of work
for a tablet server.</li>
+<li><strong>tablet servers</strong> - a set of servers that hosts reads
and writes for tablets.  Each server hosts a distinct set of tablets at any given time, but
the tablets may be hosted by different servers over time.</li>
+<li><strong>timestamp</strong> - the portion of the key that controls versioning.
 Otherwise identical keys with differing timestamps are considered to be versions of a single
<em>cell</em>.  Accumulo can be configured to keep the <em>N</em>
newest versions of each <em>cell</em>.  When a deletion entry is inserted, it
deletes all earlier versions for its cell.</li>
+<li><strong>value</strong> - immutable bytes associated with a particular
key.</li>
 </ul>
   </div>
 



Mime
View raw message