HBASE-11268 HTablePool is now a deprecated class, should update docs to reflect this (Misty Stanley-Jones)
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Michael Stack
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@ -1518,65 +1518,67 @@ if (!b) {
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any given time. When creating HTable instances, it is advisable to use the same <link
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xlink:href="http://hbase.apache.org/apidocs/org/apache/hadoop/hbase/HBaseConfiguration">HBaseConfiguration</link>
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instance. This will ensure sharing of ZooKeeper and socket instances to the RegionServers
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which is usually what you want. For example, this is preferred:
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which is usually what you want. For example, this is preferred:</para>
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<programlisting>HBaseConfiguration conf = HBaseConfiguration.create();
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HTable table1 = new HTable(conf, "myTable");
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HTable table2 = new HTable(conf, "myTable");</programlisting>
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as opposed to this:
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<para>as opposed to this:</para>
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<programlisting>HBaseConfiguration conf1 = HBaseConfiguration.create();
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HTable table1 = new HTable(conf1, "myTable");
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HBaseConfiguration conf2 = HBaseConfiguration.create();
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HTable table2 = new HTable(conf2, "myTable");</programlisting>
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For more information about how connections are handled in the HBase client, see <link
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xlink:href="http://hbase.apache.org/apidocs/org/apache/hadoop/hbase/client/HConnectionManager.html">HConnectionManager</link>. </para>
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<section
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xml:id="client.connection.pooling">
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<title>Connection Pooling</title>
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<para>For applications which require high-end multithreaded access (e.g., web-servers or
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application servers that may serve many application threads in a single JVM), one
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solution is <link
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xlink:href="http://hbase.apache.org/apidocs/org/apache/hadoop/hbase/client/HTablePool.html">HTablePool</link>.
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But as written currently, it is difficult to control client resource consumption when
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using HTablePool. </para>
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<para> Another solution is to precreate an <classname>HConnection</classname> using
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<programlisting>// Create a connection to the cluster.
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<para>For more information about how connections are handled in the HBase client,
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see <link xlink:href="http://hbase.apache.org/apidocs/org/apache/hadoop/hbase/client/HConnectionManager.html">HConnectionManager</link>.
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</para>
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<section xml:id="client.connection.pooling"><title>Connection Pooling</title>
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<para>For applications which require high-end multithreaded access (e.g., web-servers or application servers that may serve many application threads
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in a single JVM), you can pre-create an <classname>HConnection</classname>, as shown in
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the following example:</para>
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<example>
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<title>Pre-Creating a <code>HConnection</code></title>
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<programlisting>// Create a connection to the cluster.
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HConnection connection = HConnectionManager.createConnection(Configuration);
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HTableInterface table = connection.getTable("myTable");
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// use table as needed, the table returned is lightweight
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table.close();
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// use the connection for other access to the cluster
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connection.close();</programlisting>
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Constructing HTableInterface implementation is very lightweight and resources are
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controlled/shared if you go this route. </para>
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</section>
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</section>
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<section
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xml:id="client.writebuffer">
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<title>WriteBuffer and Batch Methods</title>
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<para>If <xref
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linkend="perf.hbase.client.autoflush" /> is turned off on <link
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xlink:href="http://hbase.apache.org/apidocs/org/apache/hadoop/hbase/client/HTable.html">HTable</link>,
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<classname>Put</classname>s are sent to RegionServers when the writebuffer is filled.
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The writebuffer is 2MB by default. Before an HTable instance is discarded, either
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<methodname>close()</methodname> or <methodname>flushCommits()</methodname> should be
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invoked so Puts will not be lost. </para>
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<para>Note: <code>htable.delete(Delete);</code> does not go in the writebuffer! This only
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applies to Puts. </para>
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<para>For additional information on write durability, review the <link
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xlink:href="../acid-semantics.html">ACID semantics</link> page. </para>
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<para>For fine-grained control of batching of <classname>Put</classname>s or
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<classname>Delete</classname>s, see the <link
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xlink:href="http://hbase.apache.org/apidocs/org/apache/hadoop/hbase/client/HTable.html#batch%28java.util.List%29">batch</link>
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methods on HTable. </para>
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</section>
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<section
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xml:id="client.external">
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<title>External Clients</title>
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<para>Information on non-Java clients and custom protocols is covered in <xref
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linkend="external_apis" />
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</para>
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</section>
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</section>
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</example>
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<para>Constructing HTableInterface implementation is very lightweight and resources are
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controlled.</para>
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<warning>
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<title><code>HTablePool</code> is Deprecated</title>
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<para>Previous versions of this guide discussed <code>HTablePool</code>, which was
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deprecated in HBase 0.94, 0.95, and 0.96, and removed in 0.98.1, by <link
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xlink:href="https://issues.apache.org/jira/browse/HBASE-6580">HBASE-6500</link>.
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Please use <link xlink:href="http://hbase.apache.org/apidocs/org/apache/hadoop/hbase/client/HConnection.html"><code>HConnection</code></link> instead.</para>
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</warning>
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</section>
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</section>
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<section xml:id="client.writebuffer"><title>WriteBuffer and Batch Methods</title>
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<para>If <xref linkend="perf.hbase.client.autoflush" /> is turned off on
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<link xlink:href="http://hbase.apache.org/apidocs/org/apache/hadoop/hbase/client/HTable.html">HTable</link>,
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<classname>Put</classname>s are sent to RegionServers when the writebuffer
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is filled. The writebuffer is 2MB by default. Before an HTable instance is
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discarded, either <methodname>close()</methodname> or
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<methodname>flushCommits()</methodname> should be invoked so Puts
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will not be lost.
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</para>
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<para>Note: <code>htable.delete(Delete);</code> does not go in the writebuffer! This only applies to Puts.
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</para>
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<para>For additional information on write durability, review the <link xlink:href="../acid-semantics.html">ACID semantics</link> page.
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</para>
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<para>For fine-grained control of batching of
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<classname>Put</classname>s or <classname>Delete</classname>s,
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see the <link xlink:href="http://hbase.apache.org/apidocs/org/apache/hadoop/hbase/client/HTable.html#batch%28java.util.List%29">batch</link> methods on HTable.
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</para>
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</section>
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<section xml:id="client.external"><title>External Clients</title>
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<para>Information on non-Java clients and custom protocols is covered in <xref linkend="external_apis" />
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</para>
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</section>
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</section>
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<section xml:id="client.filter"><title>Client Request Filters</title>
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<para><link xlink:href="http://hbase.apache.org/apidocs/org/apache/hadoop/hbase/client/Get.html">Get</link> and <link xlink:href="http://hbase.apache.org/apidocs/org/apache/hadoop/hbase/client/Scan.html">Scan</link> instances can be
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