gora-commits mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From build...@apache.org
Subject svn commit: r897652 - in /websites/staging/gora/trunk/content: ./ current/gora-hbase.html
Date Wed, 12 Feb 2014 18:12:43 GMT
Author: buildbot
Date: Wed Feb 12 18:12:43 2014
New Revision: 897652

Log:
Staging update by buildbot for gora

Modified:
    websites/staging/gora/trunk/content/   (props changed)
    websites/staging/gora/trunk/content/current/gora-hbase.html

Propchange: websites/staging/gora/trunk/content/
------------------------------------------------------------------------------
--- cms:source-revision (original)
+++ cms:source-revision Wed Feb 12 18:12:43 2014
@@ -1 +1 @@
-1567702
+1567707

Modified: websites/staging/gora/trunk/content/current/gora-hbase.html
==============================================================================
--- websites/staging/gora/trunk/content/current/gora-hbase.html (original)
+++ websites/staging/gora/trunk/content/current/gora-hbase.html Wed Feb 12 18:12:43 2014
@@ -160,28 +160,29 @@ module enables <a href="http://hbase.apa
 
 <p>Here you can see that we require the definition of two child elements within the

 <code>gora-orm</code> mapping configuration, namely;</p>
-<ol>
-<li>The table element; where we specify: </li>
-<li>the HBase table name e.g. <b>Employee</b>, </li>
-<li>the type and definition of families we wish to create within HBase. In this case
we create one family which could have a combination of any of the following characteristics;</li>
-<li><b>name</b>: family name e.g. info</li>
-<li><b>compression</b>: the compression option to use in HBase. Please
see <a href="http://hbase.apache.org/book/compression.html">HBase documentation</a>.</li>
-<li><b>blockCache</b>:  an LRU cache that contains three levels of block
priority to allow for scan-resistance and in-memory ColumnFamilies. Please see <a href="https://hbase.apache.org/book/regionserver.arch.html#block.cache">HBase
documentation</a>.</li>
-<li><b>blockSize</b>: The blocksize can be configured for each ColumnFamily
in a table, and this defaults to 64k. Larger cell values require larger blocksizes. There
is an inverse relationship between blocksize and the resulting StoreFile indexes (i.e., if
the blocksize is doubled then the resulting indexes should be roughly halved). Please see
<a href="http://hbase.apache.org/book/perf.schema.html#schema.cf.blocksize">HBase documentation</a>.
</li>
-<li><b>bloomFilter</b>: Bloom Filters can be enabled per-ColumnFamily.
We use <code>HColumnDescriptor.setBloomFilterType(NONE | ROW | ROWCOL)</code>
to enable blooms per Column Family. Default = NONE for no bloom filters. If ROW, the hash
of the row will be added to the bloom on each insert. If ROWCOL, the hash of the row + column
family name + column family qualifier will be added to the bloom on each key insert. Please
see <a href="http://hbase.apache.org/book/perf.schema.html#schema.bloom">HBase documentation</a>.</li>
-<li><b>maxVersions</b>: The maximum number of row versions to store is
configured per column family via <code>HColumnDescriptor</code>. The default for
max versions is <b>3</b>. This is an important parameter because HBase does not
overwrite row values, but rather stores different values per row by time (and qualifier).
Excess versions are removed during major compaction's. The number of max versions may need
to be increased or decreased depending on application needs. Please see <a href="http://hbase.apache.org/book/schema.versions.html">HBase
documentation</a>.</li>
-<li><b>timeToLive</b>: ColumnFamilies can set a TTL length in seconds,
and HBase will automatically delete rows once the expiration time is reached. This applies
to all versions of a row - even the current one. The TTL time encoded in the HBase for the
row is specified in UTC. Please see <a href="https://hbase.apache.org/book/ttl.html">HBase
documentation</a>.</li>
-<li><b>inMemory</b>: ColumnFamilies can optionally be defined as in-memory.
Data is still persisted to disk, just like any other ColumnFamily. In-memory blocks have the
highest priority in the Block Cache, but it is not a guarantee that the entire table will
be in memory. Please see <a href="http://hbase.apache.org/book/perf.schema.html#cf.in.memory">HBase
documentation</a>.</li>
-<li>Specification of persistent fields which values should map to;</li>
-<li>the Persistent class name e.g. <b>org.apache.gora.examples.generated.Employee</b>,
</li>
-<li>the keyClass e.g. <b>java.lang.String</b> which specifies the keys
which map to the field 
-values, </li>
-<li>the Table e.g. <b>Employee</b> which matches to the above Table definition,</li>
-<li>finally fields which are to be persisted into HBase need to be configured such
that they 
-receive a <b>name</b> e.g. (name, dateOfBirth, ssn and salary respectively),
the column <b>family</b> 
-to which they belong e.g. (all info in this case) and an additional <b>qualifier</b>,
which enables 
-more granular control over the data to be persisted into HBase.</li>
-</ol>
+<p>The table element; where we specify: 
+<em> a parameter relating to the HBase table name e.g. name=<b>"Employee"</b>,

+</em> a nested element containing the type and definition of families we wish to create
within HBase. In this case we create one family <b>info</b> which could have a
combination of any of the following parameters;</p>
+<div class="codehilite"><pre><span class="nt">&lt;b&gt;</span>name<span
class="nt">&lt;/b&gt;</span>: family name e.g. info
+<span class="nt">&lt;b&gt;</span>compression<span class="nt">&lt;/b&gt;</span>:
the compression option to use in HBase. Please see <span class="nt">&lt;a</span>
<span class="na">href=</span><span class="s">&quot;http://hbase.apache.org/book/compression.html&quot;</span><span
class="nt">&gt;</span>HBase documentation<span class="nt">&lt;/a&gt;</span>.
+<span class="nt">&lt;b&gt;</span>blockCache<span class="nt">&lt;/b&gt;</span>:
 an LRU cache that contains three levels of block priority to allow for scan-resistance and
in-memory ColumnFamilies. Please see <span class="nt">&lt;a</span> <span
class="na">href=</span><span class="s">&quot;https://hbase.apache.org/book/regionserver.arch.html#block.cache&quot;</span><span
class="nt">&gt;</span>HBase documentation<span class="nt">&lt;/a&gt;</span>.
+<span class="nt">&lt;b&gt;</span>blockSize<span class="nt">&lt;/b&gt;</span>:
The blocksize can be configured for each ColumnFamily in a table, and this defaults to 64k.
Larger cell values require larger blocksizes. There is an inverse relationship between blocksize
and the resulting StoreFile indexes (i.e., if the blocksize is doubled then the resulting
indexes should be roughly halved). Please see <span class="nt">&lt;a</span>
<span class="na">href=</span><span class="s">&quot;http://hbase.apache.org/book/perf.schema.html#schema.cf.blocksize&quot;</span><span
class="nt">&gt;</span>HBase documentation<span class="nt">&lt;/a&gt;</span>.

+<span class="nt">&lt;b&gt;</span>bloomFilter<span class="nt">&lt;/b&gt;</span>:
Bloom Filters can be enabled per-ColumnFamily. We use <span class="nt">&lt;code&gt;</span>HColumnDescriptor.setBloomFilterType(NONE
| ROW | ROWCOL)<span class="nt">&lt;/code&gt;</span> to enable blooms
per Column Family. Default = NONE for no bloom filters. If ROW, the hash of the row will be
added to the bloom on each insert. If ROWCOL, the hash of the row + column family name + column
family qualifier will be added to the bloom on each key insert. Please see <span class="nt">&lt;a</span>
<span class="na">href=</span><span class="s">&quot;http://hbase.apache.org/book/perf.schema.html#schema.bloom&quot;</span><span
class="nt">&gt;</span>HBase documentation<span class="nt">&lt;/a&gt;</span>.
+<span class="nt">&lt;b&gt;</span>maxVersions<span class="nt">&lt;/b&gt;</span>:
The maximum number of row versions to store is configured per column family via <span class="nt">&lt;code&gt;</span>HColumnDescriptor<span
class="nt">&lt;/code&gt;</span>. The default for max versions is <span
class="nt">&lt;b&gt;</span>3<span class="nt">&lt;/b&gt;</span>.
This is an important parameter because HBase does not overwrite row values, but rather stores
different values per row by time (and qualifier). Excess versions are removed during major
compaction&#39;s. The number of max versions may need to be increased or decreased depending
on application needs. Please see <span class="nt">&lt;a</span> <span class="na">href=</span><span
class="s">&quot;http://hbase.apache.org/book/schema.versions.html&quot;</span><span
class="nt">&gt;</span>HBase documentation<span class="nt">&lt;/a&gt;</span>.
+<span class="nt">&lt;b&gt;</span>timeToLive<span class="nt">&lt;/b&gt;</span>:
ColumnFamilies can set a TTL length in seconds, and HBase will automatically delete rows once
the expiration time is reached. This applies to all versions of a row - even the current one.
The TTL time encoded in the HBase for the row is specified in UTC. Please see <span class="nt">&lt;a</span>
<span class="na">href=</span><span class="s">&quot;https://hbase.apache.org/book/ttl.html&quot;</span><span
class="nt">&gt;</span>HBase documentation<span class="nt">&lt;/a&gt;</span>.
+<span class="nt">&lt;b&gt;</span>inMemory<span class="nt">&lt;/b&gt;</span>:
ColumnFamilies can optionally be defined as in-memory. Data is still persisted to disk, just
like any other ColumnFamily. In-memory blocks have the highest priority in the Block Cache,
but it is not a guarantee that the entire table will be in memory. Please see <span class="nt">&lt;a</span>
<span class="na">href=</span><span class="s">&quot;http://hbase.apache.org/book/perf.schema.html#cf.in.memory&quot;</span><span
class="nt">&gt;</span>HBase documentation<span class="nt">&lt;/a&gt;</span>.
+</pre></div>
+
+
+<p>The class element where we specify of persistent fields which values should map
to. This contains;
+<em> a parameter containing the Persistent class name e.g. <b>org.apache.gora.examples.generated.Employee</b>,

+</em> a parameter containing the keyClass e.g. <b>java.lang.String</b>
which specifies the keys which map to the field values, 
+<em> a parameter containing the Table name e.g. <b>Employee</b> which matches
to the above Table definition,
+</em> finally nested child element(s) mapping fields which are to be persisted into
HBase. These fields need to be configured such that they receive;</p>
+<div class="codehilite"><pre>a parameter containing the <span class="nt">&lt;b&gt;</span>name<span
class="nt">&lt;/b&gt;</span> e.g. (name, dateOfBirth, ssn and salary respectively),

+a parameter containing the column <span class="nt">&lt;b&gt;</span>family<span
class="nt">&lt;/b&gt;</span> to which they belong e.g. (all info in this
case), 
+an optional parameter <span class="nt">&lt;b&gt;</span>qualifier<span
class="nt">&lt;/b&gt;</span>, which enables more granular control over the
data to be persisted into HBase.
+</pre></div>
 
   </div> <!-- /container (main block) -->
 



Mime
View raw message