Edit D:\app\Administrator\product\11.2.0\dbhome_1\oc4j\j2ee\oc4j_applications\applications\em\em\online_help\tdpii\tdpii_repcont014.htm
<!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" xml:lang="en" lang="en"> <head> <meta http-equiv="Content-Type" content="text/html; charset=us-ascii" /> <meta http-equiv="Content-Style-Type" content="text/css" /> <meta http-equiv="Content-Script-Type" content="text/javascript" /> <title>About Hub-And-Spoke Replication Environments</title> <meta name="generator" content="Oracle DARB XHTML Converter (Mode = ohj/ohw) - Version 5.1.1 Build 005" /> <meta name="date" content="2009-06-04T17:1:1Z" /> <meta name="robots" content="noarchive" /> <meta name="doctitle" content="About Hub-And-Spoke Replication Environments" /> <meta name="relnum" content="11g Release 2 (11.2)" /> <meta name="partnum" content="E10703-01" /> <link rel="copyright" href="./dcommon/html/cpyr.htm" title="Copyright" type="text/html" /> <link rel="stylesheet" href="./dcommon/css/blafdoc.css" title="Oracle BLAFDoc" type="text/css" /> <link rel="contents" href="toc.htm" title="Contents" type="text/html" /> <link rel="prev" href="tdpii_repcont013.htm" title="Previous" type="text/html" /> <link rel="next" href="tdpii_repcont015.htm" title="Next" type="text/html" /> <script src="./callback.js" type="text/javascript"></script> <noscript>Your browser does not support JavaScript. This help page requires JavaScript to render correctly.</noscript> </head> <body> <div class="zz-skip-header"><a href="#BEGIN">Skip Headers</a></div> <table class="simple oac_no_warn" summary="" cellspacing="0" cellpadding="0" width="100%"> <col width="86%" /> <col width="*" /> <tr valign="bottom"> <td align="left"></td> <td align="center"><a href="tdpii_repcont013.htm"><img src="./dcommon/gifs/leftnav.gif" alt="Previous" /><br /> <span class="icon">Previous</span></a> </td> <td align="center"><a href="tdpii_repcont015.htm"><img src="./dcommon/gifs/rightnav.gif" alt="Next" /><br /> <span class="icon">Next</span></a></td> </tr> </table> <p><a id="CIHJEIDB" name="CIHJEIDB"></a><a id="TDPII134" name="TDPII134"></a></p> <div class="sect3"><!-- infolevel="all" infotype="General" --> <h1>About Hub-And-Spoke Replication Environments<a id="sthref161" name="sthref161"></a><a id="sthref162" name="sthref162"></a></h1> <a name="BEGIN" id="BEGIN"></a> <p>A <span class="bold">hub-and-spoke replication environment</span> is one in which a central database, or hub, communicates with secondary databases, or spokes. The spokes do not communicate directly with each other. In a hub-and-spoke replication environment, the spokes might or might not allow changes to the replicated database objects.</p> <p>If the spokes do not allow changes, then they contain read-only replicas of the database objects at the hub. This type of hub-and-spoke replication environment typically has the following basic components:</p> <ul> <li> <p>The hub has a capture process or synchronous capture to capture changes to the replicated database objects.</p> </li> <li> <p>The hub has propagations that send the captured changes to each of the spokes.</p> </li> <li> <p>Each spoke has an apply process to apply changes from the hub.</p> </li> <li> <p>For the best performance, each capture process and apply process has its own queue.</p> </li> </ul> <p><a href="#CIHCDDEC">Figure: Hub-and-Spoke Replication Environment with Read-Only Spokes</a> shows a hub-and-spoke replication environment with read-only spokes.</p> <div class="figure"><a id="CIHCDDEC" name="CIHCDDEC"></a><a id="TDPII225" name="TDPII225"></a> <p class="titleinfigure">Hub-and-Spoke Replication Environment with Read-Only Spokes</p> <img src="img/tdpii502.gif" alt="Description of this figure follows" title="Description of this figure follows" longdesc="img_text/tdpii502.htm" /><br /> <a id="sthref163" name="sthref163" href="img_text/tdpii502.htm">Description of "Hub-and-Spoke Replication Environment with Read-Only Spokes"</a><br /> <br /></div> <!-- class="figure" --> <p>If the spokes allow changes to the database objects, then typically the changes are captured and sent back to the hub, and the hub replicates the changes with the other spokes. This type of hub-and-spoke replication environment typically has the following basic components:</p> <ul> <li> <p>The hub has a capture process or synchronous capture to capture changes to the replicated database objects.</p> </li> <li> <p>The hub has propagations that send the captured changes to each of the spokes.</p> </li> <li> <p>Each spoke has a capture process or synchronous capture to capture changes to the replicated database objects.</p> </li> <li> <p>Each spoke has a propagation that sends changes made at the spoke back to the hub.</p> </li> <li> <p>Each spoke has an apply process to apply changes from the hub and from the other spokes.</p> </li> <li> <p>The hub has a separate apply process to apply changes from each spoke. A different apply process must apply changes from each spoke.</p> </li> <li> <p>For the best performance, each capture process and apply process has its own queue.</p> </li> </ul> <p><a href="#CIHBEFBE">Figure: Hub-and-Spoke Replication Environment with Read/Write Spokes</a> shows a hub-and-spoke replication environment with read/write spokes.</p> <div class="figure"><a id="CIHBEFBE" name="CIHBEFBE"></a><a id="TDPII226" name="TDPII226"></a> <p class="titleinfigure">Hub-and-Spoke Replication Environment with Read/Write Spokes</p> <img src="img/tdpii503.gif" alt="Description of this figure follows" title="Description of this figure follows" longdesc="img_text/tdpii503.htm" /><br /> <a id="sthref164" name="sthref164" href="img_text/tdpii503.htm">Description of "Hub-and-Spoke Replication Environment with Read/Write Spokes"</a><br /> <br /></div> <!-- class="figure" --> <p>Typically, in a hub-and-spoke replication environment that allows changes at spoke databases, you should configure conflict resolution to keep the replicated database objects synchronized. Some hub-and-spoke replication environments allow changes to the replicated database objects at some spokes but not at others.</p> <p>You can configure a hub-and-spoke replication environment using the Setup Streams Replication Wizard in Oracle Enterprise Manager or the configuration procedures in the <code>DBMS_STREAMS_ADM</code> package.</p> <p>See <a href="tdpii_intro2ii004.htm#CFHJAAEA">"When to Replicate Data with Oracle Streams"</a> for information about when hub-and-spoke replication is useful.</p> <div class="helpinfonotealso"> <h2>Related Topics</h2> <p><a href="tdpii_repcont023.htm#BABBIBCD">Tutorial: Configuring Hub-and-Spoke Replication with Local Capture Processes</a></p> <p><a href="tdpii_repcont010.htm#BABGAACC">About Conflicts and Conflict Resolution</a></p> <p><a href="tdpii_repcont012.htm#CIHGGCCB">About the Common Types of Oracle Streams Replication Environments</a></p> </div> </div> <!-- class="sect3" --> <!-- Start Footer --> <div class="footer"> <table class="simple oac_no_warn" summary="" cellspacing="0" cellpadding="0" width="100%"> <col width="86%" /> <col width="*" /> <tr> <td align="left"><span class="copyrightlogo">Copyright © 2007, 2009, Oracle and/or its affiliates. All rights reserved.</span><br /> <a href="./dcommon/html/cpyr.htm"><span class="copyrightlogo">Legal Notices</span></a></td> <td align="center"><a href="tdpii_repcont013.htm"><img src="./dcommon/gifs/leftnav.gif" alt="Previous" /><br /> <span class="icon">Previous</span></a> </td> <td align="center"><a href="tdpii_repcont015.htm"><img src="./dcommon/gifs/rightnav.gif" alt="Next" /><br /> <span class="icon">Next</span></a></td> </tr> </table> </div> <!-- class="footer" --> </body> </html>
Ms-Dos/Windows
Unix
Write backup
jsp File Browser version 1.2 by
www.vonloesch.de