mirror of
https://github.com/berkeleydb/libdb.git
synced 2024-11-17 01:26:25 +00:00
143 lines
5.7 KiB
HTML
143 lines
5.7 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>Bulk Transfers</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="Getting Started with Replicated Berkeley DB Applications" />
|
|||
|
|
<link rel="up" href="addfeatures.html" title="Chapter 5. Additional Features" />
|
|||
|
|
<link rel="prev" href="c2ctransfer.html" title="Client to Client Transfer" />
|
|||
|
|
</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">Bulk Transfers</th>
|
|||
|
|
</tr>
|
|||
|
|
<tr>
|
|||
|
|
<td width="20%" align="left"><a accesskey="p" href="c2ctransfer.html">Prev</a> </td>
|
|||
|
|
<th width="60%" align="center">Chapter 5. Additional Features</th>
|
|||
|
|
<td width="20%" align="right"> </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="bulk"></a>Bulk Transfers</h2>
|
|||
|
|
</div>
|
|||
|
|
</div>
|
|||
|
|
</div>
|
|||
|
|
<p>
|
|||
|
|
By default, messages are sent from the master to replicas as they are generated.
|
|||
|
|
This can degrade replication performance because the various participating
|
|||
|
|
environments must handle a fair amount of network I/O activity.
|
|||
|
|
</p>
|
|||
|
|
<p>
|
|||
|
|
You can alleviate this problem by configuring your master environment for bulk
|
|||
|
|
transfers. Bulk transfers simply cause replication messages to accumulate in a
|
|||
|
|
buffer until a triggering event occurs. When this event occurs, the entire
|
|||
|
|
contents of the buffer is sent to the replica, thereby eliminating excessive
|
|||
|
|
network I/O.
|
|||
|
|
</p>
|
|||
|
|
<p>
|
|||
|
|
Note that if you are using replica to replica transfers, then you might want any
|
|||
|
|
replica that can service replication requests to also be configured for bulk
|
|||
|
|
transfers.
|
|||
|
|
</p>
|
|||
|
|
<p>
|
|||
|
|
The events that result in a bulk transfer of replication messages to a replica
|
|||
|
|
will differ depending on if the transmitting environment is a master or a
|
|||
|
|
replica.
|
|||
|
|
</p>
|
|||
|
|
<p>
|
|||
|
|
If the servicing environment is a master environment, then bulk transfer
|
|||
|
|
occurs when:
|
|||
|
|
</p>
|
|||
|
|
<div class="orderedlist">
|
|||
|
|
<ol type="1">
|
|||
|
|
<li>
|
|||
|
|
<p>
|
|||
|
|
Bulk transfers are configured for the master environment, and
|
|||
|
|
</p>
|
|||
|
|
</li>
|
|||
|
|
<li>
|
|||
|
|
<p>
|
|||
|
|
the message buffer is full or
|
|||
|
|
</p>
|
|||
|
|
</li>
|
|||
|
|
<li>
|
|||
|
|
<p>
|
|||
|
|
a permanent record (for example, a transaction commit or a
|
|||
|
|
checkpoint record) is placed in the buffer for the replica.
|
|||
|
|
</p>
|
|||
|
|
</li>
|
|||
|
|
</ol>
|
|||
|
|
</div>
|
|||
|
|
<p>
|
|||
|
|
If the servicing environment is a replica environment (that is, replica to replica
|
|||
|
|
transfers are in use), then a bulk transfer occurs when:
|
|||
|
|
</p>
|
|||
|
|
<div class="orderedlist">
|
|||
|
|
<ol type="1">
|
|||
|
|
<li>
|
|||
|
|
<p>
|
|||
|
|
Bulk transfers are configured for the transmitting replica, and
|
|||
|
|
</p>
|
|||
|
|
</li>
|
|||
|
|
<li>
|
|||
|
|
<p>
|
|||
|
|
the message buffer is full or
|
|||
|
|
</p>
|
|||
|
|
</li>
|
|||
|
|
<li>
|
|||
|
|
<p>
|
|||
|
|
the replica servicing the request is able to completely satisfy
|
|||
|
|
the request with the contents of the message buffer.
|
|||
|
|
</p>
|
|||
|
|
</li>
|
|||
|
|
</ol>
|
|||
|
|
</div>
|
|||
|
|
<p>
|
|||
|
|
To configure bulk transfers, specify
|
|||
|
|
|
|||
|
|
|
|||
|
|
<span>
|
|||
|
|
<code class="literal">ReplicationConfig.BULK</code> and
|
|||
|
|
<code class="literal">true</code> to
|
|||
|
|
<code class="methodname">Environment.setReplicationConfig()</code>.
|
|||
|
|
To turn off this feature, specify
|
|||
|
|
<code class="literal">false</code> for the
|
|||
|
|
<code class="literal">ReplicationConfig.BULK</code> field.
|
|||
|
|
</span>
|
|||
|
|
</p>
|
|||
|
|
</div>
|
|||
|
|
<div class="navfooter">
|
|||
|
|
<hr />
|
|||
|
|
<table width="100%" summary="Navigation footer">
|
|||
|
|
<tr>
|
|||
|
|
<td width="40%" align="left"><a accesskey="p" href="c2ctransfer.html">Prev</a> </td>
|
|||
|
|
<td width="20%" align="center">
|
|||
|
|
<a accesskey="u" href="addfeatures.html">Up</a>
|
|||
|
|
</td>
|
|||
|
|
<td width="40%" align="right"> </td>
|
|||
|
|
</tr>
|
|||
|
|
<tr>
|
|||
|
|
<td width="40%" align="left" valign="top">Client to Client Transfer </td>
|
|||
|
|
<td width="20%" align="center">
|
|||
|
|
<a accesskey="h" href="index.html">Home</a>
|
|||
|
|
</td>
|
|||
|
|
<td width="40%" align="right" valign="top"> </td>
|
|||
|
|
</tr>
|
|||
|
|
</table>
|
|||
|
|
</div>
|
|||
|
|
</body>
|
|||
|
|
</html>
|