mirror of
https://github.com/berkeleydb/libdb.git
synced 2024-11-16 17:16:25 +00:00
236 lines
9.6 KiB
HTML
236 lines
9.6 KiB
HTML
<?xml version="1.0" encoding="UTF-8" standalone="no"?>
|
||
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
|
||
<html xmlns="http://www.w3.org/1999/xhtml">
|
||
<head>
|
||
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
|
||
<title>Ex_rep: a replication example</title>
|
||
<link rel="stylesheet" href="gettingStarted.css" type="text/css" />
|
||
<meta name="generator" content="DocBook XSL Stylesheets V1.73.2" />
|
||
<link rel="start" href="index.html" title="Berkeley DB Programmer's Reference Guide" />
|
||
<link rel="up" href="rep.html" title="Chapter 12. Berkeley DB Replication" />
|
||
<link rel="prev" href="rep_faq.html" title="Replication FAQ" />
|
||
<link rel="next" href="rep_ex_comm.html" title="Ex_rep_base: a TCP/IP based communication infrastructure" />
|
||
</head>
|
||
<body>
|
||
<div xmlns="" class="navheader">
|
||
<div class="libver">
|
||
<p>Library Version 11.2.5.2</p>
|
||
</div>
|
||
<table width="100%" summary="Navigation header">
|
||
<tr>
|
||
<th colspan="3" align="center">Ex_rep: a replication example</th>
|
||
</tr>
|
||
<tr>
|
||
<td width="20%" align="left"><a accesskey="p" href="rep_faq.html">Prev</a> </td>
|
||
<th width="60%" align="center">Chapter 12.
|
||
Berkeley DB Replication
|
||
</th>
|
||
<td width="20%" align="right"> <a accesskey="n" href="rep_ex_comm.html">Next</a></td>
|
||
</tr>
|
||
</table>
|
||
<hr />
|
||
</div>
|
||
<div class="sect1" lang="en" xml:lang="en">
|
||
<div class="titlepage">
|
||
<div>
|
||
<div>
|
||
<h2 class="title" style="clear: both"><a id="rep_ex"></a>Ex_rep: a replication example</h2>
|
||
</div>
|
||
</div>
|
||
</div>
|
||
<p>Ex_rep, found in the <code class="filename">examples_c/ex_rep</code> subdirectory
|
||
of the Berkeley DB distribution, is a simple but complete demonstration of a
|
||
replicated application. The application is a mock stock ticker. The
|
||
master accepts a stock symbol and a numerical value as input, and
|
||
stores this information into a replicated database; either master or
|
||
clients can display the contents of the database, given an empty input
|
||
line.</p>
|
||
<p>There are two versions of the application: ex_rep_mgr uses Replication
|
||
Manager, while ex_rep_base uses the replication Base API. This is
|
||
intended to demonstrate that, while the basic function of the
|
||
application is the same in either case, the replication support
|
||
infrastructure differs markedly.</p>
|
||
<p>The communication infrastructure demonstrated with ex_rep_base has the
|
||
same dependencies on system networking and threading support as does
|
||
the Replication Manager (see the <a class="xref" href="rep.html#rep_intro" title="Replication introduction">Replication introduction</a>). The Makefile created by the standard UNIX
|
||
configuration will build the ex_rep examples on most platforms. Enter
|
||
"make ex_rep_mgr" and/or "make ex_rep_base" to build them.</p>
|
||
<p>The synopsis for both programs is as follows:</p>
|
||
<code class="literal">ex_rep_xxx <span class="bold"><strong>-h home</strong></span> <span class="bold"><strong>-l host:port</strong></span> [<span class="bold"><strong>-MC</strong></span>] [<span class="bold"><strong>-r host:port</strong></span>] [<span class="bold"><strong>-R host:port</strong></span>] [<span class="bold"><strong>-a all|quorum</strong></span>] [<span class="bold"><strong>-b</strong></span>] [<span class="bold"><strong>-n sites</strong></span>] [<span class="bold"><strong>-p priority</strong></span>] [<span class="bold"><strong>-v</strong></span>]</code>
|
||
<p>
|
||
where "ex_rep_xxx" is either "ex_rep_mgr" or "ex_rep_base". The only
|
||
difference is that:
|
||
</p>
|
||
<div class="itemizedlist">
|
||
<ul type="disc">
|
||
<li>
|
||
<p>
|
||
specifying <span class="bold"><strong>-M</strong></span> or
|
||
<span class="bold"><strong>-C</strong></span> is optional for ex_rep_mgr,
|
||
but one of these options must be specified for ex_rep_base.
|
||
</p>
|
||
</li>
|
||
<li>
|
||
<p>
|
||
The <span class="bold"><strong>-n</strong></span> option is not supported
|
||
supported by ex_rep_mgr. That option specifies the number of
|
||
nodes in the replication group. When you use the Replication
|
||
Manager, this number is automatically determined for you.
|
||
</p>
|
||
</li>
|
||
</ul>
|
||
</div>
|
||
<p>
|
||
The options apply to either version of the program except where noted.
|
||
They are as follows:
|
||
</p>
|
||
<div class="variablelist">
|
||
<dl>
|
||
<dt>
|
||
<span class="term">
|
||
<span class="bold">
|
||
<strong>-h</strong>
|
||
</span>
|
||
</span>
|
||
</dt>
|
||
<dd>Specify a home directory for the database environment.</dd>
|
||
<dt>
|
||
<span class="term">
|
||
<span class="bold">
|
||
<strong>-l</strong>
|
||
</span>
|
||
</span>
|
||
</dt>
|
||
<dd>Listen on local host "host" at port "port" for incoming connections.</dd>
|
||
<dt>
|
||
<span class="term">
|
||
<span class="bold">
|
||
<strong>-M</strong>
|
||
</span>
|
||
</span>
|
||
</dt>
|
||
<dd>Configure this process as a master.</dd>
|
||
<dt>
|
||
<span class="term">
|
||
<span class="bold">
|
||
<strong>-C</strong>
|
||
</span>
|
||
</span>
|
||
</dt>
|
||
<dd>Configure this process as a client.</dd>
|
||
<dt>
|
||
<span class="term">
|
||
<span class="bold">
|
||
<strong>-r</strong>
|
||
</span>
|
||
</span>
|
||
</dt>
|
||
<dd>
|
||
Identifies the helper site used for joining the group.
|
||
</dd>
|
||
<dt>
|
||
<span class="term">
|
||
<span class="bold">
|
||
<strong>-R</strong>
|
||
</span>
|
||
</span>
|
||
</dt>
|
||
<dd>
|
||
Identifies a remote peer to be used for joining the group. This
|
||
peer is used for syncing purposes. See
|
||
<a class="xref" href="rep_mastersync.html#rep_c2c_sync" title="Client-to-client synchronization">Client-to-client synchronization</a>
|
||
for more information.
|
||
</dd>
|
||
<dt>
|
||
<span class="term">
|
||
<span class="bold">
|
||
<strong>-a</strong>
|
||
</span>
|
||
</span>
|
||
</dt>
|
||
<dd>
|
||
Specify repmgr acknowledgement policy of all or quorum. See
|
||
<a href="../api_reference/C/repmgrset_ack_policy.html" class="olink">DB_ENV->repmgr_set_ack_policy()</a> for more information (ex_rep_mgr
|
||
only.)
|
||
</dd>
|
||
<dt>
|
||
<span class="term">
|
||
<span class="bold">
|
||
<strong>-b</strong>
|
||
</span>
|
||
</span>
|
||
</dt>
|
||
<dd>
|
||
Indicates that bulk transfer should be used. See <a class="xref" href="rep_bulk.html" title="Bulk transfer">Bulk transfer</a> for more
|
||
information.
|
||
</dd>
|
||
<dt>
|
||
<span class="term">
|
||
<span class="bold">
|
||
<strong>-n</strong>
|
||
</span>
|
||
</span>
|
||
</dt>
|
||
<dd>
|
||
Specify the total number of sites in the replication group
|
||
(ex_rep_base only).
|
||
</dd>
|
||
<dt>
|
||
<span class="term">
|
||
<span class="bold">
|
||
<strong>-p</strong>
|
||
</span>
|
||
</span>
|
||
</dt>
|
||
<dd>Set the
|
||
election priority. See
|
||
<a class="xref" href="rep_elect.html" title="Elections">Elections</a> for more
|
||
information.
|
||
</dd>
|
||
<dt>
|
||
<span class="term">
|
||
<span class="bold">
|
||
<strong>-v</strong>
|
||
</span>
|
||
</span>
|
||
</dt>
|
||
<dd>Indicates that additional informational and debugging output should be enabled.</dd>
|
||
</dl>
|
||
</div>
|
||
<p>A typical ex_rep_mgr session begins with a command such as the
|
||
following, to start a master:</p>
|
||
<pre class="programlisting">ex_rep_mgr -M -p 100 -h DIR1 -l localhost:30100</pre>
|
||
<p>and several clients:</p>
|
||
<pre class="programlisting">ex_rep_mgr -C -p 50 -h DIR2 -l localhost:30101 -r localhost:30100
|
||
ex_rep_mgr -C -p 10 -h DIR3 -l localhost:30102 -r localhost:30100
|
||
ex_rep_mgr -C -p 0 -h DIR4 -l localhost:30103 -r localhost:30100</pre>
|
||
<p>
|
||
In this example, the client with home directory DIR4 can never become a
|
||
master (its priority is 0). Both of the other clients can become
|
||
masters, but the one with home directory DIR2 is preferred. Priorities
|
||
are assigned by the application and should reflect the desirability of
|
||
having particular clients take over as master in the case that the
|
||
master fails.
|
||
</p>
|
||
</div>
|
||
<div class="navfooter">
|
||
<hr />
|
||
<table width="100%" summary="Navigation footer">
|
||
<tr>
|
||
<td width="40%" align="left"><a accesskey="p" href="rep_faq.html">Prev</a> </td>
|
||
<td width="20%" align="center">
|
||
<a accesskey="u" href="rep.html">Up</a>
|
||
</td>
|
||
<td width="40%" align="right"> <a accesskey="n" href="rep_ex_comm.html">Next</a></td>
|
||
</tr>
|
||
<tr>
|
||
<td width="40%" align="left" valign="top">Replication FAQ </td>
|
||
<td width="20%" align="center">
|
||
<a accesskey="h" href="index.html">Home</a>
|
||
</td>
|
||
<td width="40%" align="right" valign="top"> Ex_rep_base: a TCP/IP based communication infrastructure</td>
|
||
</tr>
|
||
</table>
|
||
</div>
|
||
</body>
|
||
</html>
|