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38      <p>To add a new site to the replication group all that is needed
39is for the client member to join.  Berkeley DB will perform an
40internal initialization from the master to the client automatically
41and will run recovery on the client to bring it up to date
42with the master.</p>
43      <p>For Base API applications, connecting to a
44new site in the replication group happens whenever the
45<a href="../api_reference/C/repmessage.html" class="olink">DB_ENV-&gt;rep_process_message()</a> method returns <a href="../api_reference/C/repmessage.html#repmsg_DB_REP_NEWSITE" class="olink">DB_REP_NEWSITE</a>.  The application
46should assign the new site a local environment ID number, and all future
47messages from the site passed to <a href="../api_reference/C/repmessage.html" class="olink">DB_ENV-&gt;rep_process_message()</a> should include that
48environment ID number.  It is possible, of course, for the application
49to be aware of a new site before the return of <a href="../api_reference/C/repmessage.html" class="olink">DB_ENV-&gt;rep_process_message()</a> (for
50example, applications using connection-oriented protocols are likely to
51detect new sites immediately, while applications using broadcast
52protocols may not).</p>
53      <p>Regardless, in applications supporting the dynamic addition of database
54environments to replication groups, environments joining an existing
55replication group may need to provide contact information.  (For
56example, in an application using TCP/IP sockets, a DNS name or IP
57address might be a reasonable value to provide.)  This can be done using
58the <span class="bold"><strong>cdata</strong></span> parameter to the <a href="../api_reference/C/repstart.html" class="olink">DB_ENV-&gt;rep_start()</a> method.  The information
59referenced by <span class="bold"><strong>cdata</strong></span> is wrapped in the initial contact message
60sent by the new environment, and is provided to the existing members of
61the group using the <span class="bold"><strong>rec</strong></span> parameter returned by <a href="../api_reference/C/repmessage.html" class="olink">DB_ENV-&gt;rep_process_message()</a>.
62If no additional information was provided for Berkeley DB to forward to the
63existing members of the group, the <span class="bold"><strong>data</strong></span> field of the <span class="bold"><strong>rec</strong></span>
64parameter passed to the <a href="../api_reference/C/repmessage.html" class="olink">DB_ENV-&gt;rep_process_message()</a> method will be NULL after
65<a href="../api_reference/C/repmessage.html" class="olink">DB_ENV-&gt;rep_process_message()</a> returns <a href="../api_reference/C/repmessage.html#repmsg_DB_REP_NEWSITE" class="olink">DB_REP_NEWSITE</a>.</p>
66      <p>Replication Manager automatically distributes contact information
67using the mechanisms previously described.</p>
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