Jekyll build from master:8939ce9 Added javadoc links in clients documentation
Project: http://git-wip-us.apache.org/repos/asf/accumulo-website/repo Commit: http://git-wip-us.apache.org/repos/asf/accumulo-website/commit/a3b64131 Tree: http://git-wip-us.apache.org/repos/asf/accumulo-website/tree/a3b64131 Diff: http://git-wip-us.apache.org/repos/asf/accumulo-website/diff/a3b64131 Branch: refs/heads/asf-site Commit: a3b6413186c1ccce14f108a92ade0c4a5a9f78e5 Parents: 2d7cc3d Author: Mike Walch <[email protected]> Authored: Wed May 24 17:38:39 2017 -0400 Committer: Mike Walch <[email protected]> Committed: Wed May 24 17:38:39 2017 -0400 ---------------------------------------------------------------------- docs/unreleased/getting-started/clients.html | 35 ++++++++++++----------- feed.xml | 4 +-- 2 files changed, 20 insertions(+), 19 deletions(-) ---------------------------------------------------------------------- http://git-wip-us.apache.org/repos/asf/accumulo-website/blob/a3b64131/docs/unreleased/getting-started/clients.html ---------------------------------------------------------------------- diff --git a/docs/unreleased/getting-started/clients.html b/docs/unreleased/getting-started/clients.html index 4a82259..35c2a6c 100644 --- a/docs/unreleased/getting-started/clients.html +++ b/docs/unreleased/getting-started/clients.html @@ -381,12 +381,12 @@ communicating. Code to do this is as follows:</p> </code></pre> </div> -<p>The PasswordToken is the most common implementation of an <code class="highlighter-rouge">AuthenticationToken</code>. +<p>The <a href="https://static.javadoc.io/org.apache.accumulo/accumulo-core/1.8.1/org/apache/accumulo/core/client/security/tokens/PasswordToken.html";>PasswordToken</a> is the most common implementation of an <a href="https://static.javadoc.io/org.apache.accumulo/accumulo-core/1.8.1/org/apache/accumulo/core/client/security/tokens/AuthenticationToken.html";>AuthenticationToken</a>. This general interface allow authentication as an Accumulo user to come from -a variety of sources or means. The CredentialProviderToken leverages the Hadoop +a variety of sources or means. The <a href="https://static.javadoc.io/org.apache.accumulo/accumulo-core/1.8.1/org/apache/accumulo/core/client/security/tokens/CredentialProviderToken.html";>CredentialProviderToken</a> leverages the Hadoop CredentialProviders (new in Hadoop 2.6).</p> -<p>For example, the CredentialProviderToken can be used in conjunction with a Java +<p>For example, the <a href="https://static.javadoc.io/org.apache.accumulo/accumulo-core/1.8.1/org/apache/accumulo/core/client/security/tokens/CredentialProviderToken.html";>CredentialProviderToken</a> can be used in conjunction with a Java KeyStore to alleviate passwords stored in cleartext. When stored in HDFS, a single KeyStore can be used across an entire instance. Be aware that KeyStores stored on the local filesystem must be made available to all nodes in the Accumulo cluster.</p> @@ -396,16 +396,16 @@ the local filesystem must be made available to all nodes in the Accumulo cluster </code></pre> </div> -<p>The KerberosToken can be provided to use the authentication provided by Kerberos. +<p>The <a href="https://static.javadoc.io/org.apache.accumulo/accumulo-core/1.8.1/org/apache/accumulo/core/client/security/tokens/KerberosToken.html";>KerberosToken</a> can be provided to use the authentication provided by Kerberos. Using Kerberos requires external setup and additional configuration, but provides a single point of authentication through HDFS, YARN and ZooKeeper and allowing for password-less authentication with Accumulo.</p> <h2 id="writing-data">Writing Data</h2> -<p>Data are written to Accumulo by creating Mutation objects that represent all the +<p>Data are written to Accumulo by creating <a href="https://static.javadoc.io/org.apache.accumulo/accumulo-core/1.8.1/org/apache/accumulo/core/data/Mutation.html";>Mutation</a> objects that represent all the changes to the columns of a single row. The changes are made atomically in the -TabletServer. Clients then add Mutations to a BatchWriter which submits them to +TabletServer. Clients then add Mutations to a <a href="https://static.javadoc.io/org.apache.accumulo/accumulo-core/1.8.1/org/apache/accumulo/core/client/BatchWriter.html";>BatchWriter</a> which submits them to the appropriate TabletServers.</p> <p>Mutations can be created thus:</p> @@ -425,7 +425,7 @@ the appropriate TabletServers.</p> <h3 id="batchwriter">BatchWriter</h3> -<p>The BatchWriter is highly optimized to send Mutations to multiple TabletServers +<p>The <a href="https://static.javadoc.io/org.apache.accumulo/accumulo-core/1.8.1/org/apache/accumulo/core/client/BatchWriter.html";>BatchWriter</a> is highly optimized to send Mutations to multiple TabletServers and automatically batches Mutations destined for the same TabletServer to amortize network overhead. Care must be taken to avoid changing the contents of any Object passed to the BatchWriter since it keeps objects in memory while @@ -449,11 +449,11 @@ batching.</p> <h3 id="conditionalwriter">ConditionalWriter</h3> -<p>The ConditionalWriter enables efficient, atomic read-modify-write operations on +<p>The <a href="https://static.javadoc.io/org.apache.accumulo/accumulo-core/1.8.1/org/apache/accumulo/core/client/ConditionalWriter.html";>ConditionalWriter</a> enables efficient, atomic read-modify-write operations on rows. The ConditionalWriter writes special Mutations which have a list of per column conditions that must all be met before the mutation is applied. The conditions are checked in the tablet server while a row lock is -held (Mutations written by the BatchWriter will not obtain a row +held (Mutations written by the <a href="https://static.javadoc.io/org.apache.accumulo/accumulo-core/1.8.1/org/apache/accumulo/core/client/BatchWriter.html";>BatchWriter</a> will not obtain a row lock). The conditions that can be checked for a column are equality and absence. For example a conditional mutation can require that column A is absent inorder to be applied. Iterators can be applied when checking @@ -513,7 +513,7 @@ to efficiently return ranges of consecutive keys and their associated values.</p <h3 id="scanner">Scanner</h3> -<p>To retrieve data, Clients use a Scanner, which acts like an Iterator over +<p>To retrieve data, Clients use a <a href="https://static.javadoc.io/org.apache.accumulo/accumulo-core/1.8.1org/apache/accumulo/core/client/Scanner.html";>Scanner</a>, which acts like an Iterator over keys and values. Scanners can be configured to start and stop at particular keys, and to return a subset of the columns available.</p> @@ -545,13 +545,13 @@ scanning. There are three possible ways that a row could change in Accumulo :</p </ul> <p>Isolation guarantees that either all or none of the changes made by these -operations on a row are seen. Use the IsolatedScanner to obtain an isolated +operations on a row are seen. Use the <a href="https://static.javadoc.io/org.apache.accumulo/accumulo-core/1.8.1/org/apache/accumulo/core/client/IsolatedScanner.html";>IsolatedScanner</a> to obtain an isolated view of an Accumulo table. When using the regular scanner it is possible to see a non isolated view of a row. For example if a mutation modifies three columns, it is possible that you will only see two of those modifications. With the isolated scanner either all three of the changes are seen or none.</p> -<p>The IsolatedScanner buffers rows on the client side so a large row will not +<p>The <a href="https://static.javadoc.io/org.apache.accumulo/accumulo-core/1.8.1/org/apache/accumulo/core/client/IsolatedScanner.html";>IsolatedScanner</a> buffers rows on the client side so a large row will not crash a tablet server. By default rows are buffered in memory, but the user can easily supply their own buffer if they wish to buffer to disk when rows are large.</p> @@ -565,10 +565,10 @@ for example code that uses the IsolatedScanner.</p> simultaneously. This arises when accessing a set of rows that are not consecutive whose IDs have been retrieved from a secondary index, for example.</p> -<p>The BatchScanner is configured similarly to the Scanner; it can be configured to -retrieve a subset of the columns available, but rather than passing a single Range, +<p>The <a href="https://static.javadoc.io/org.apache.accumulo/accumulo-core/1.8.1/org/apache/accumulo/core/client/BatchScanner.html";>BatchScanner</a> is configured similarly to the <a href="https://static.javadoc.io/org.apache.accumulo/accumulo-core/1.8.1org/apache/accumulo/core/client/Scanner.html";>Scanner</a>; it can be configured to +retrieve a subset of the columns available, but rather than passing a single <a href="https://static.javadoc.io/org.apache.accumulo/accumulo-core/1.8.1/org/apache/accumulo/core/data/Range.html";>Range</a>, BatchScanners accept a set of Ranges. It is important to note that the keys returned -by a BatchScanner are not in sorted order since the keys streamed are from multiple +by a <a href="https://static.javadoc.io/org.apache.accumulo/accumulo-core/1.8.1/org/apache/accumulo/core/client/BatchScanner.html";>BatchScanner</a> are not in sorted order since the keys streamed are from multiple TabletServers in parallel.</p> <div class="language-java highlighter-rouge"><pre class="highlight"><code><span class="n">ArrayList</span><span class="o"><</span><span class="n">Range</span><span class="o">></span> <span class="n">ranges</span> <span class="o">=</span> <span class="k">new</span> <span class="n">ArrayList</span><span class="o"><</span><span class="n">Range</span><span class="o">>();</span> @@ -587,8 +587,8 @@ TabletServers in parallel.</p> <p>For more example code, see the <a href="https://github.com/apache/accumulo-examples/blob/master/docs/batch.md";>batch writing and scanning example</a>.</p> -<p>At this time, there is no client side isolation support for the BatchScanner. -You may consider using the WholeRowIterator with the BatchScanner to achieve +<p>At this time, there is no client side isolation support for the <a href="https://static.javadoc.io/org.apache.accumulo/accumulo-core/1.8.1/org/apache/accumulo/core/client/BatchScanner.html";>BatchScanner</a>. +You may consider using the <a href="https://static.javadoc.io/org.apache.accumulo/accumulo-core/1.8.1/org/apache/accumulo/core/iterators/user/WholeRowIterator.html";>WholeRowIterator</a> with the BatchScanner to achieve isolation. The drawback of this approach is that entire rows are read into memory on the server side. If a row is too big, it may crash a tablet server.</p> @@ -711,6 +711,7 @@ Letâs create a table, add some data, scan the table, and delete it.</p> </code></pre> </div> + </div> </div> http://git-wip-us.apache.org/repos/asf/accumulo-website/blob/a3b64131/feed.xml ---------------------------------------------------------------------- diff --git a/feed.xml b/feed.xml index 2bf2fe2..544c606 100644 --- a/feed.xml +++ b/feed.xml @@ -6,8 +6,8 @@ </description> <link>https://accumulo.apache.org/</link> <atom:link href="https://accumulo.apache.org/feed.xml"; rel="self" type="application/rss+xml"/> - <pubDate>Tue, 23 May 2017 09:49:52 -0400</pubDate> - <lastBuildDate>Tue, 23 May 2017 09:49:52 -0400</lastBuildDate> + <pubDate>Wed, 24 May 2017 17:38:31 -0400</pubDate> + <lastBuildDate>Wed, 24 May 2017 17:38:31 -0400</lastBuildDate> <generator>Jekyll v3.3.1</generator> <item>
