You are viewing a plain text version of this content. The canonical link for it is here.
Posted to commits@zookeeper.apache.org by ph...@apache.org on 2008/10/17 00:31:24 UTC
svn commit: r705380 - in /hadoop/zookeeper/trunk: ./ docs/
src/docs/src/documentation/content/xdocs/
Author: phunt
Date: Thu Oct 16 15:31:23 2008
New Revision: 705380
URL: http://svn.apache.org/viewvc?rev=705380&view=rev
Log:
ZOOKEEPER-194. Fix terminology in zookeeperAdmin.xml
Modified:
hadoop/zookeeper/trunk/CHANGES.txt
hadoop/zookeeper/trunk/docs/zookeeperAdmin.html
hadoop/zookeeper/trunk/docs/zookeeperAdmin.pdf
hadoop/zookeeper/trunk/docs/zookeeperOver.html
hadoop/zookeeper/trunk/docs/zookeeperOver.pdf
hadoop/zookeeper/trunk/docs/zookeeperProgrammers.html
hadoop/zookeeper/trunk/docs/zookeeperProgrammers.pdf
hadoop/zookeeper/trunk/src/docs/src/documentation/content/xdocs/zookeeperAdmin.xml
hadoop/zookeeper/trunk/src/docs/src/documentation/content/xdocs/zookeeperOver.xml
hadoop/zookeeper/trunk/src/docs/src/documentation/content/xdocs/zookeeperProgrammers.xml
Modified: hadoop/zookeeper/trunk/CHANGES.txt
URL: http://svn.apache.org/viewvc/hadoop/zookeeper/trunk/CHANGES.txt?rev=705380&r1=705379&r2=705380&view=diff
==============================================================================
--- hadoop/zookeeper/trunk/CHANGES.txt (original)
+++ hadoop/zookeeper/trunk/CHANGES.txt Thu Oct 16 15:31:23 2008
@@ -35,6 +35,9 @@
BUGFIXES:
+ ZOOKEEPER-194. Fix terminology in zookeeperAdmin.xml
+ (Flavio Paiva Junqueira)
+
ZOOKEEPER-151. Document change to server configuration
(Flavio Paiva Junqueira)
Modified: hadoop/zookeeper/trunk/docs/zookeeperAdmin.html
URL: http://svn.apache.org/viewvc/hadoop/zookeeper/trunk/docs/zookeeperAdmin.html?rev=705380&r1=705379&r2=705380&view=diff
==============================================================================
--- hadoop/zookeeper/trunk/docs/zookeeperAdmin.html (original)
+++ hadoop/zookeeper/trunk/docs/zookeeperAdmin.html Thu Oct 16 15:31:23 2008
@@ -316,23 +316,24 @@
<a name="N10032"></a><a name="sc_systemReq"></a>
<h3 class="h4">System Requirements</h3>
<p>ZooKeeper runs in Java, release 1.5 or greater (JDK 5 or greater).
- It runs as group of hosts called a quorum. Three ZooKeeper hosts per
- quorum is the minimum recommended quorum size. At Yahoo!, ZooKeeper is
- usually deployed on dedicated RHEL boxes, with dual-core processors, 2GB
- of RAM, and 80GB IDE hard drives.</p>
-<a name="N1003C"></a><a name="sc_zkMulitServerSetup"></a>
+ It runs as an <em>ensemble</em> of ZooKeeper servers. Three ZooKeeper
+ servers is the minimum recommended size for an ensemble, and we also recommend that
+ they run on separate machines. At Yahoo!, ZooKeeper is usually deployed on
+ dedicated RHEL boxes, with dual-core processors, 2GB of RAM, and 80GB IDE hard
+ drives.</p>
+<a name="N1003F"></a><a name="sc_zkMulitServerSetup"></a>
<h3 class="h4">Clustered (Multi-Server) Setup</h3>
<p>For reliable ZooKeeper service, you should deploy ZooKeeper in a
- cluster known as a <em>quorum</em>. As long as a majority
- of the quorum are up, the service will be available. Because Zookeeper
+ cluster known as an <em>ensemble</em>. As long as a majority
+ of the ensemble are up, the service will be available. Because Zookeeper
requires a majority, it is best to use an
odd number of machines. For example, with four machines ZooKeeper can
only handle the failure of a single machine; if two machines fail, the
remaining two machines do not constitute a majority. However, with five
machines ZooKeeper can handle the failure of two machines. </p>
-<p>Here are the steps to setting a server that will be part of a
- quorum. These steps should be performed on every host in the
- quorum:</p>
+<p>Here are the steps to setting a server that will be part of an
+ ensemble. These steps should be performed on every host in the
+ ensemble:</p>
<ol>
<li>
@@ -401,8 +402,8 @@
though about a few here:</p>
-<p>Every machine that is part of the ZooKeeper quorum should know
- about every other machine in the quorum. You accomplish this with
+<p>Every machine that is part of the ZooKeeper ensemble should know
+ about every other machine in the ensemble. You accomplish this with
the series of lines of the form <strong>server.id=host:port:port</strong>. The parameters <strong>host</strong> and <strong>port</strong> are straightforward. You attribute the
server id to each machine by creating a file named
<span class="codefrag filename">myid</span>, one for each server, which resides in
@@ -411,7 +412,7 @@
consists of a single line containing only the text of that machine's
id. So <span class="codefrag filename">myid</span> of server 1 would contain the text
"1" and nothing else. The id must be unique within the
- quorum.</p>
+ ensemble.</p>
</li>
@@ -488,7 +489,7 @@
</li>
</ol>
-<a name="N100D0"></a><a name="sc_singleAndDevSetup"></a>
+<a name="N100D3"></a><a name="sc_singleAndDevSetup"></a>
<h3 class="h4">Single Server and Developer Setup</h3>
<p>If you want to setup ZooKeeper for development purposes, you will
probably want to setup a single server instance of ZooKeeper, and then
@@ -506,7 +507,7 @@
</div>
-<a name="N100F1"></a><a name="ch_administration"></a>
+<a name="N100F4"></a><a name="ch_administration"></a>
<h2 class="h3">Administration</h2>
<div class="section">
<p>This section contains information about running and maintaining
@@ -621,22 +622,22 @@
</li>
</ul>
-<a name="N1015D"></a><a name="sc_designing"></a>
+<a name="N10160"></a><a name="sc_designing"></a>
<h3 class="h4">Designing a ZooKeeper Deployment</h3>
<p></p>
-<a name="N10166"></a><a name="sc_provisioning"></a>
+<a name="N10169"></a><a name="sc_provisioning"></a>
<h3 class="h4">Provisioning</h3>
<p></p>
-<a name="N1016F"></a><a name="sc_strengthsAndLimitations"></a>
+<a name="N10172"></a><a name="sc_strengthsAndLimitations"></a>
<h3 class="h4">Things to Consider: ZooKeeper Strengths and Limitations</h3>
<p></p>
-<a name="N10178"></a><a name="sc_administering"></a>
+<a name="N1017B"></a><a name="sc_administering"></a>
<h3 class="h4">Administering</h3>
<p></p>
-<a name="N10181"></a><a name="sc_monitoring"></a>
+<a name="N10184"></a><a name="sc_monitoring"></a>
<h3 class="h4">Monitoring</h3>
<p></p>
-<a name="N1018A"></a><a name="sc_logging"></a>
+<a name="N1018D"></a><a name="sc_logging"></a>
<h3 class="h4">Logging</h3>
<p>ZooKeeper uses <strong>log4j</strong> version 1.2 as
its logging infrastructure. The ZooKeeper default <span class="codefrag filename">log4j.properties</span>
@@ -646,10 +647,10 @@
<p>For more information, see
<a href="http://logging.apache.org/log4j/1.2/manual.html#defaultInit">Log4j Default Initialization Procedure</a>
of the log4j manual.</p>
-<a name="N101AA"></a><a name="sc_troubleshooting"></a>
+<a name="N101AD"></a><a name="sc_troubleshooting"></a>
<h3 class="h4">Troubleshooting</h3>
<p></p>
-<a name="N101B3"></a><a name="sc_configuration"></a>
+<a name="N101B6"></a><a name="sc_configuration"></a>
<h3 class="h4">Configuration Parameters</h3>
<p>ZooKeeper's behavior is governed by the ZooKeeper configuration
file. This file is designed so that the exact same file can be used by
@@ -657,7 +658,7 @@
layouts are the same. If servers use different configuration files, care
must be taken to ensure that the list of servers in all of the different
configuration files match.</p>
-<a name="N101BC"></a><a name="sc_minimumConfiguration"></a>
+<a name="N101BF"></a><a name="sc_minimumConfiguration"></a>
<h4>Minimum Configuration</h4>
<p>Here are the minimum configuration keywords that must be defined
in the configuration file:</p>
@@ -704,7 +705,7 @@
</dd>
</dl>
-<a name="N101E3"></a><a name="sc_advancedConfiguration"></a>
+<a name="N101E6"></a><a name="sc_advancedConfiguration"></a>
<h4>Advanced Configuration</h4>
<p>The configuration settings in the section are optional. You can
use them to further fine tune the behaviour of your ZooKeeper servers.
@@ -795,10 +796,10 @@
</dd>
</dl>
-<a name="N10243"></a><a name="sc_clusterOptions"></a>
+<a name="N10246"></a><a name="sc_clusterOptions"></a>
<h4>Cluster Options</h4>
-<p>The options in this section are designed for use in quorums --
- that is, when deploying clusters of servers.</p>
+<p>The options in this section are designed for use with an ensemble
+ of servers -- that is, when deploying clusters of servers.</p>
<dl>
<dt>
@@ -843,7 +844,7 @@
<div class="content">
<p>Turning on leader selection is highly recommended when
- you have more than three ZooKeeper servers in a quorum.</p>
+ you have more than three ZooKeeper servers in an ensemble.</p>
</div>
</div>
@@ -855,7 +856,7 @@
</dt>
<dd>
<p>(No Java system property)</p>
-<p>servers making up the ZooKeeper quorum. When the server
+<p>servers making up the ZooKeeper ensemble. When the server
starts up, it determines which server it is by looking for the
file <span class="codefrag filename">myid</span> in the data directory. That file
contains the server number, in ASCII, and it should match
@@ -885,7 +886,7 @@
</dl>
<p></p>
-<a name="N102A0"></a><a name="Unsafe+Options"></a>
+<a name="N102A3"></a><a name="Unsafe+Options"></a>
<h4>Unsafe Options</h4>
<p>The following options can be useful, but be careful when you use
them. The risk of each is explained along with the explanation of what
@@ -930,7 +931,7 @@
</dd>
</dl>
-<a name="N102D2"></a><a name="sc_zkCommands"></a>
+<a name="N102D5"></a><a name="sc_zkCommands"></a>
<h3 class="h4">ZooKeeper Commands: The Four Letter Words</h3>
<p>ZooKeeper responds to a small set of commands. Each command is
composed of four letters. You issue the commands to ZooKeeper via telnet
@@ -979,7 +980,7 @@
<pre class="code">$ echo ruok | nc 127.0.0.1 5111
imok
</pre>
-<a name="N10304"></a><a name="sc_dataFileManagement"></a>
+<a name="N10307"></a><a name="sc_dataFileManagement"></a>
<h3 class="h4">Data File Management</h3>
<p>ZooKeeper stores its data in a data directory and its transaction
log in a transaction log directory. By default these two directories are
@@ -987,7 +988,7 @@
transaction log files in a separate directory than the data files.
Throughput increases and latency decreases when transaction logs reside
on a dedicated log devices.</p>
-<a name="N1030D"></a><a name="The+Data+Directory"></a>
+<a name="N10310"></a><a name="The+Data+Directory"></a>
<h4>The Data Directory</h4>
<p>This directory has two files in it:</p>
<ul>
@@ -1033,14 +1034,14 @@
idempotent nature of its updates. By replaying the transaction log
against fuzzy snapshots ZooKeeper gets the state of the system at the
end of the log.</p>
-<a name="N10349"></a><a name="The+Log+Directory"></a>
+<a name="N1034C"></a><a name="The+Log+Directory"></a>
<h4>The Log Directory</h4>
<p>The Log Directory contains the ZooKeeper transaction logs.
Before any update takes place, ZooKeeper ensures that the transaction
that represents the update is written to non-volatile storage. A new
log file is started each time a snapshot is begun. The log file's
suffix is the first zxid written to that log.</p>
-<a name="N10353"></a><a name="File+Management"></a>
+<a name="N10356"></a><a name="File+Management"></a>
<h4>File Management</h4>
<p>The format of snapshot and log files does not change between
standalone ZooKeeper servers and different configurations of
@@ -1057,7 +1058,7 @@
needs the latest complete fuzzy snapshot and the log files from the
start of that snapshot. The PurgeTxnLog utility implements a simple
retention policy that administrators can use.</p>
-<a name="N10364"></a><a name="sc_commonProblems"></a>
+<a name="N10367"></a><a name="sc_commonProblems"></a>
<h3 class="h4">Things to Avoid</h3>
<p>Here are some common problems you can avoid by configuring
ZooKeeper correctly:</p>
@@ -1111,7 +1112,7 @@
</dd>
</dl>
-<a name="N10388"></a><a name="sc_bestPractices"></a>
+<a name="N1038B"></a><a name="sc_bestPractices"></a>
<h3 class="h4">Best Practices</h3>
<p>For best results, take note of the following list of good
Zookeeper practices. <em>[tbd...]</em>
Modified: hadoop/zookeeper/trunk/docs/zookeeperAdmin.pdf
URL: http://svn.apache.org/viewvc/hadoop/zookeeper/trunk/docs/zookeeperAdmin.pdf?rev=705380&r1=705379&r2=705380&view=diff
==============================================================================
Binary files - no diff available.
Modified: hadoop/zookeeper/trunk/docs/zookeeperOver.html
URL: http://svn.apache.org/viewvc/hadoop/zookeeper/trunk/docs/zookeeperOver.html?rev=705380&r1=705379&r2=705380&view=diff
==============================================================================
--- hadoop/zookeeper/trunk/docs/zookeeperOver.html (original)
+++ hadoop/zookeeper/trunk/docs/zookeeperOver.html Thu Oct 16 15:31:23 2008
@@ -265,7 +265,7 @@
<p>
<strong>ZooKeeper is replicated.</strong> Like the
distributed processes it coordinates, ZooKeeper itself is intended to be
- replicated over a sets of machines called quorums.</p>
+ replicated over a sets of hosts called an ensemble.</p>
<table class="ForrestTable" cellspacing="1" cellpadding="4">
<tr>
<td>ZooKeeper Service</td>
Modified: hadoop/zookeeper/trunk/docs/zookeeperOver.pdf
URL: http://svn.apache.org/viewvc/hadoop/zookeeper/trunk/docs/zookeeperOver.pdf?rev=705380&r1=705379&r2=705380&view=diff
==============================================================================
Binary files - no diff available.
Modified: hadoop/zookeeper/trunk/docs/zookeeperProgrammers.html
URL: http://svn.apache.org/viewvc/hadoop/zookeeper/trunk/docs/zookeeperProgrammers.html?rev=705380&r1=705379&r2=705380&view=diff
==============================================================================
--- hadoop/zookeeper/trunk/docs/zookeeperProgrammers.html (original)
+++ hadoop/zookeeper/trunk/docs/zookeeperProgrammers.html Thu Oct 16 15:31:23 2008
@@ -482,11 +482,11 @@
<p>In distributed application engineering, the word
<em>node</em> can refer to a generic host machine, a
- server, a member of quorums, a client process, etc. In the ZooKeeper
+ server, a member of an ensemble, a client process, etc. In the ZooKeeper
documentatin, <em>znodes</em> refer to the data nodes.
<em>Servers</em> to refer to machines that make up the
ZooKeeper service; <em>quorum peers</em> refer to the
- servers that make up a quorum; client refers to any host or process
+ servers that make up an ensemble; client refers to any host or process
which uses a ZooKeeper service.</p>
</div>
@@ -1272,14 +1272,14 @@
change. Consider the scenario of two clients, A and B. If client
A sets the value of a znode /a from 0 to 1, then tells client B
to read /a, client B may read the old value of 0, depending on
- which server in the ZooKeeper quorum it is connected to. If it
+ which server it is connected to. If it
is important that Client A and Client B read the same value,
Client B should should call the <strong>sync()</strong> method from the ZooKeeper API
method before it performs its read.</p>
-<p>So, ZooKeeper by itself doesn't guarantee instantaneous,
- atomic, synchronization across its quorum, but ZooKeeper
+<p>So, ZooKeeper by itself doesn't guarantee that changes occur
+ synchronously across all servers, but ZooKeeper
primitives can be used to construct higher level functions that
- provide complete client synchronization. (For more information,
+ provide useful client synchronization. (For more information,
see the <a href="recipes.html">Zookeeper Recipes</a>.
<em>[tbd:..]</em>).</p>
</dd>
Modified: hadoop/zookeeper/trunk/docs/zookeeperProgrammers.pdf
URL: http://svn.apache.org/viewvc/hadoop/zookeeper/trunk/docs/zookeeperProgrammers.pdf?rev=705380&r1=705379&r2=705380&view=diff
==============================================================================
Binary files - no diff available.
Modified: hadoop/zookeeper/trunk/src/docs/src/documentation/content/xdocs/zookeeperAdmin.xml
URL: http://svn.apache.org/viewvc/hadoop/zookeeper/trunk/src/docs/src/documentation/content/xdocs/zookeeperAdmin.xml?rev=705380&r1=705379&r2=705380&view=diff
==============================================================================
--- hadoop/zookeeper/trunk/src/docs/src/documentation/content/xdocs/zookeeperAdmin.xml (original)
+++ hadoop/zookeeper/trunk/src/docs/src/documentation/content/xdocs/zookeeperAdmin.xml Thu Oct 16 15:31:23 2008
@@ -72,27 +72,28 @@
<title>System Requirements</title>
<para>ZooKeeper runs in Java, release 1.5 or greater (JDK 5 or greater).
- It runs as group of hosts called a quorum. Three ZooKeeper hosts per
- quorum is the minimum recommended quorum size. At Yahoo!, ZooKeeper is
- usually deployed on dedicated RHEL boxes, with dual-core processors, 2GB
- of RAM, and 80GB IDE hard drives.</para>
+ It runs as an <emphasis>ensemble</emphasis> of ZooKeeper servers. Three ZooKeeper
+ servers is the minimum recommended size for an ensemble, and we also recommend that
+ they run on separate machines. At Yahoo!, ZooKeeper is usually deployed on
+ dedicated RHEL boxes, with dual-core processors, 2GB of RAM, and 80GB IDE hard
+ drives.</para>
</section>
<section id="sc_zkMulitServerSetup">
<title>Clustered (Multi-Server) Setup</title>
<para>For reliable ZooKeeper service, you should deploy ZooKeeper in a
- cluster known as a <emphasis>quorum</emphasis>. As long as a majority
- of the quorum are up, the service will be available. Because Zookeeper
+ cluster known as an <emphasis>ensemble</emphasis>. As long as a majority
+ of the ensemble are up, the service will be available. Because Zookeeper
requires a majority, it is best to use an
odd number of machines. For example, with four machines ZooKeeper can
only handle the failure of a single machine; if two machines fail, the
remaining two machines do not constitute a majority. However, with five
machines ZooKeeper can handle the failure of two machines. </para>
- <para>Here are the steps to setting a server that will be part of a
- quorum. These steps should be performed on every host in the
- quorum:</para>
+ <para>Here are the steps to setting a server that will be part of an
+ ensemble. These steps should be performed on every host in the
+ ensemble:</para>
<orderedlist>
<listitem>
@@ -141,8 +142,8 @@
settings in the section <xref linkend="sc_configuration" />. A word
though about a few here:</para>
- <para>Every machine that is part of the ZooKeeper quorum should know
- about every other machine in the quorum. You accomplish this with
+ <para>Every machine that is part of the ZooKeeper ensemble should know
+ about every other machine in the ensemble. You accomplish this with
the series of lines of the form <emphasis
role="bold">server.id=host:port:port</emphasis>. The parameters <emphasis
role="bold">host</emphasis> and <emphasis
@@ -154,7 +155,7 @@
consists of a single line containing only the text of that machine's
id. So <filename>myid</filename> of server 1 would contain the text
"1" and nothing else. The id must be unique within the
- quorum.</para>
+ ensemble.</para>
</listitem>
<listitem>
@@ -492,8 +493,8 @@
<section id="sc_clusterOptions">
<title>Cluster Options</title>
- <para>The options in this section are designed for use in quorums --
- that is, when deploying clusters of servers.</para>
+ <para>The options in this section are designed for use with an ensemble
+ of servers -- that is, when deploying clusters of servers.</para>
<variablelist>
<varlistentry>
@@ -541,7 +542,7 @@
<note>
<para>Turning on leader selection is highly recommended when
- you have more than three ZooKeeper servers in a quorum.</para>
+ you have more than three ZooKeeper servers in an ensemble.</para>
</note>
</listitem>
</varlistentry>
@@ -552,7 +553,7 @@
<listitem>
<para>(No Java system property)</para>
- <para>servers making up the ZooKeeper quorum. When the server
+ <para>servers making up the ZooKeeper ensemble. When the server
starts up, it determines which server it is by looking for the
file <filename>myid</filename> in the data directory. That file
contains the server number, in ASCII, and it should match
Modified: hadoop/zookeeper/trunk/src/docs/src/documentation/content/xdocs/zookeeperOver.xml
URL: http://svn.apache.org/viewvc/hadoop/zookeeper/trunk/src/docs/src/documentation/content/xdocs/zookeeperOver.xml?rev=705380&r1=705379&r2=705380&view=diff
==============================================================================
--- hadoop/zookeeper/trunk/src/docs/src/documentation/content/xdocs/zookeeperOver.xml (original)
+++ hadoop/zookeeper/trunk/src/docs/src/documentation/content/xdocs/zookeeperOver.xml Thu Oct 16 15:31:23 2008
@@ -79,7 +79,7 @@
<para><emphasis role="bold">ZooKeeper is replicated.</emphasis> Like the
distributed processes it coordinates, ZooKeeper itself is intended to be
- replicated over a sets of machines called quorums.</para>
+ replicated over a sets of hosts called an ensemble.</para>
<figure>
<title>ZooKeeper Service</title>
Modified: hadoop/zookeeper/trunk/src/docs/src/documentation/content/xdocs/zookeeperProgrammers.xml
URL: http://svn.apache.org/viewvc/hadoop/zookeeper/trunk/src/docs/src/documentation/content/xdocs/zookeeperProgrammers.xml?rev=705380&r1=705379&r2=705380&view=diff
==============================================================================
--- hadoop/zookeeper/trunk/src/docs/src/documentation/content/xdocs/zookeeperProgrammers.xml (original)
+++ hadoop/zookeeper/trunk/src/docs/src/documentation/content/xdocs/zookeeperProgrammers.xml Thu Oct 16 15:31:23 2008
@@ -174,11 +174,11 @@
<note>
<para>In distributed application engineering, the word
<emphasis>node</emphasis> can refer to a generic host machine, a
- server, a member of quorums, a client process, etc. In the ZooKeeper
+ server, a member of an ensemble, a client process, etc. In the ZooKeeper
documentatin, <emphasis>znodes</emphasis> refer to the data nodes.
<emphasis>Servers</emphasis> to refer to machines that make up the
ZooKeeper service; <emphasis>quorum peers</emphasis> refer to the
- servers that make up a quorum; client refers to any host or process
+ servers that make up an ensemble; client refers to any host or process
which uses a ZooKeeper service.</para>
</note>
@@ -763,16 +763,16 @@
change. Consider the scenario of two clients, A and B. If client
A sets the value of a znode /a from 0 to 1, then tells client B
to read /a, client B may read the old value of 0, depending on
- which server in the ZooKeeper quorum it is connected to. If it
+ which server it is connected to. If it
is important that Client A and Client B read the same value,
Client B should should call the <emphasis
role="bold">sync()</emphasis> method from the ZooKeeper API
method before it performs its read.</para>
- <para>So, ZooKeeper by itself doesn't guarantee instantaneous,
- atomic, synchronization across its quorum, but ZooKeeper
+ <para>So, ZooKeeper by itself doesn't guarantee that changes occur
+ synchronously across all servers, but ZooKeeper
primitives can be used to construct higher level functions that
- provide complete client synchronization. (For more information,
+ provide useful client synchronization. (For more information,
see the <ulink
url="recipes.html">Zookeeper Recipes</ulink>.
<emphasis>[tbd:..]</emphasis>).</para>