Repository: accumulo Updated Branches: refs/heads/master bebfbd0ed -> 13201a814
ACCUMULO-4531 Removed isolation.html * Moved documentation to clients chapter were some already existed Project: http://git-wip-us.apache.org/repos/asf/accumulo/repo Commit: http://git-wip-us.apache.org/repos/asf/accumulo/commit/add22171 Tree: http://git-wip-us.apache.org/repos/asf/accumulo/tree/add22171 Diff: http://git-wip-us.apache.org/repos/asf/accumulo/diff/add22171 Branch: refs/heads/master Commit: add22171568d9bfe25e0db46105bc052d5991c37 Parents: d4d7d09 Author: Mike Walch <mwa...@apache.org> Authored: Fri Dec 2 15:07:59 2016 -0500 Committer: Mike Walch <mwa...@apache.org> Committed: Tue Dec 6 11:33:35 2016 -0500 ---------------------------------------------------------------------- docs/src/main/asciidoc/chapters/clients.txt | 9 +++-- docs/src/main/resources/isolation.html | 51 ------------------------ 2 files changed, 6 insertions(+), 54 deletions(-) ---------------------------------------------------------------------- http://git-wip-us.apache.org/repos/asf/accumulo/blob/add22171/docs/src/main/asciidoc/chapters/clients.txt ---------------------------------------------------------------------- diff --git a/docs/src/main/asciidoc/chapters/clients.txt b/docs/src/main/asciidoc/chapters/clients.txt index 958ab11..63bb937 100644 --- a/docs/src/main/asciidoc/chapters/clients.txt +++ b/docs/src/main/asciidoc/chapters/clients.txt @@ -264,8 +264,12 @@ for(Entry<Key,Value> entry : bscan) { } ---- -An example of the BatchScanner can be found at -+accumulo/docs/examples/README.batch+. +An example of the BatchScanner can be found at +accumulo/docs/examples/README.batch+. + +At this time, there is no client side isolation support for the BatchScanner. +You may consider using the WholeRowIterator 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. === Proxy @@ -281,7 +285,6 @@ The proxy server can live on any node in which the basic client API would work. means it must be able to communicate with the Master, ZooKeepers, NameNode, and the DataNodes. A proxy client only needs the ability to communicate with the proxy server. - ==== Configuration The configuration options for the proxy server live inside of a properties file. At http://git-wip-us.apache.org/repos/asf/accumulo/blob/add22171/docs/src/main/resources/isolation.html ---------------------------------------------------------------------- diff --git a/docs/src/main/resources/isolation.html b/docs/src/main/resources/isolation.html deleted file mode 100644 index fcda45e..0000000 --- a/docs/src/main/resources/isolation.html +++ /dev/null @@ -1,51 +0,0 @@ -<!-- - Licensed to the Apache Software Foundation (ASF) under one or more - contributor license agreements. See the NOTICE file distributed with - this work for additional information regarding copyright ownership. - The ASF licenses this file to You under the Apache License, Version 2.0 - (the "License"); you may not use this file except in compliance with - the License. You may obtain a copy of the License at - - http://www.apache.org/licenses/LICENSE-2.0 - - Unless required by applicable law or agreed to in writing, software - distributed under the License is distributed on an "AS IS" BASIS, - WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. - See the License for the specific language governing permissions and - limitations under the License. ---> -<html> -<head> -<title>Accumulo Isolation</title> -<link rel='stylesheet' type='text/css' href='documentation.css' media='screen'/> -</head> -<body> - -<h1>Apache Accumulo Documentation : Isolation</h1> - -<h3>Scanning</h3> - -<p>Accumulo supports the ability to present an isolated view of rows when scanning. There are three possible ways that a row could change in accumulo : -<ul> - <li>a mutation applied to a table - <li>iterators executed as part of a minor or major compaction - <li>bulk import of new files -</ul> -Isolation guarantees that either all or none of the changes made by these -operations on a row are seen. Use the <code>IsolatedScanner</code> 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. For an example of this try running the -<code>InterferenceTest</code> example. - -<p>At this time there is no client side isolation support for the -<code>BatchScanner</code>. You may consider using the -<code>WholeRowIterator</code> with the <code>BatchScanner</code> to achieve -isolation though. This drawback of doing this is that entire rows are read into -memory on the server side. If a row is too big, it may crash a tablet server. -The <code>IsolatedScanner</code> buffers rows on the client side so a large row will not crash a tablet server. - -<h3>Iterators</h3> -<p>See the user manual's chapter on iterator design for more information on considerations when Isolation is enabled.
