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<title>DB_ENV->rep_process_message()</title>
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<meta name="generator" content="DocBook XSL Stylesheets V1.73.2" />
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<link rel="start" href="index.html" title="Berkeley DB C API Reference" />
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<link rel="up" href="rep.html" title="Chapter 10. Replication Methods" />
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<link rel="prev" href="repget_timeout.html" title="DB_ENV->rep_get_timeout()" />
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<p>Library Version 11.2.5.3</p>
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<table width="100%" summary="Navigation header">
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<tr>
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<th colspan="3" align="center">DB_ENV->rep_process_message()</th>
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</tr>
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<tr>
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<td width="20%" align="left"><a accesskey="p" href="repget_timeout.html">Prev</a> </td>
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<th width="60%" align="center">Chapter 10.
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Replication Methods
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</th>
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<td width="20%" align="right"> <a accesskey="n" href="repclockskew.html">Next</a></td>
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</tr>
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<div class="sect1" lang="en" xml:lang="en">
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<div class="titlepage">
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<div>
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<div>
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<h2 class="title" style="clear: both"><a id="repmessage"></a>DB_ENV->rep_process_message()</h2>
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</div>
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</div>
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</div>
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<pre class="programlisting">#include <db.h>
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int
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DB_ENV->rep_process_message(DB_ENV *env,
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DBT *control, DBT *rec, int envid, DB_LSN *ret_lsnp) </pre>
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<p>
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The <code class="methodname">DB_ENV->rep_process_message()</code> method processes an incoming
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replication message sent by a member of the replication group to the
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local database environment.
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</p>
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<p>
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The <code class="methodname">DB_ENV->rep_process_message()</code> method is not called by most
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replication applications. It should only be called by Base API applications
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implementing their own network transport layer, explicitly holding
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replication group elections and handling replication messages outside
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of the Replication Manager framework.
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</p>
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<p>
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For implementation reasons, all incoming replication messages must be
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processed using the same <a class="link" href="env.html" title="Chapter 5. The DB_ENV Handle">DB_ENV</a> handle. It is not
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required that a single thread of control process all messages, only
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that all threads of control processing messages use the same handle.
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</p>
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<p>
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Before calling this method, the enclosing database environment must
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already have been opened by calling the
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<a class="xref" href="envopen.html" title="DB_ENV->open()">DB_ENV->open()</a> method and must
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already have been configured to send replication messages by
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calling the <a class="xref" href="reptransport.html" title="DB_ENV->rep_set_transport()">DB_ENV->rep_set_transport()</a>
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method.
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</p>
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<p>
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The <code class="methodname">DB_ENV->rep_process_message()</code> method has additional return
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values:
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</p>
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<div class="itemizedlist">
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<ul type="disc">
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<li>
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<p><a id="repmsg_DB_REP_DUPMASTER"></a>
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<span class="bold"><strong>DB_REP_DUPMASTER</strong></span>
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</p>
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<p>
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The <code class="methodname">DB_ENV->rep_process_message()</code> method will return
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<code class="literal">DB_REP_DUPMASTER</code> if the replication group has more than one
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master. The application should reconfigure itself as a client by calling the
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<a class="xref" href="repstart.html" title="DB_ENV->rep_start()">DB_ENV->rep_start()</a> method, and then call for an
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election by calling <a class="xref" href="repelect.html" title="DB_ENV->rep_elect()">DB_ENV->rep_elect()</a>.
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</p>
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</li>
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<li>
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<p><a id="repmsg_DB_REP_HOLDELECTION"></a>
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<span class="bold"><strong>DB_REP_HOLDELECTION</strong></span>
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</p>
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<p>
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The <code class="methodname">DB_ENV->rep_process_message()</code> method will return
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<code class="literal">DB_REP_HOLDELECTION</code> if an election is needed. The application
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should call for an election by calling
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<a class="xref" href="repelect.html" title="DB_ENV->rep_elect()">DB_ENV->rep_elect()</a>.
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</p>
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</li>
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<li>
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<p><a id="repmsg_DB_REP_IGNORE"></a>
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<span class="bold"><strong>DB_REP_IGNORE</strong></span>
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</p>
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<p>
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The <code class="methodname">DB_ENV->rep_process_message()</code> method will return
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<code class="literal">DB_REP_IGNORE</code> if this message cannot be processed. This is an
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indication that this message is irrelevant to the current replication state (for
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example, an old message from a previous generation arrives and is processed late).
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</p>
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</li>
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<li>
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<p><a id="repmsg_DB_REP_ISPERM"></a>
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<span class="bold"><strong>DB_REP_ISPERM</strong></span>
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</p>
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<p>
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The <code class="methodname">DB_ENV->rep_process_message()</code> method will return
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<code class="literal">DB_REP_ISPERM</code> if processing this message results in the
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processing of records that are permanent. The maximum LSN of the permanent records
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stored is returned.
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</p>
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</li>
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<li>
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<p><a id="repmsg_DB_REP_JOIN_FAILURE"></a>
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<span class="bold"><strong>DB_REP_JOIN_FAILURE</strong></span>
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</p>
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<p>
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The <code class="methodname">DB_ENV->rep_process_message()</code> method will return
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<code class="literal">DB_REP_JOIN_FAILURE</code> if a new master has been chosen but the
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client is unable to synchronize with the new master. This is possibly because the client
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has turned off automatic internal initialization by setting the
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<a class="link" href="repconfig.html#config_DB_REP_CONF_AUTOINIT">DB_REP_CONF_AUTOINIT</a>
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flag to <code class="literal">0</code>.
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</p>
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</li>
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<li>
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<p><a id="repmsg_DB_REP_NEWSITE"></a>
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<span class="bold"><strong>DB_REP_NEWSITE</strong></span>
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</p>
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<p>
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The <code class="methodname">DB_ENV->rep_process_message()</code> method will return
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<code class="literal">DB_REP_NEWSITE</code> if the system received contact information from a
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new environment. The <span class="bold"><strong>rec</strong></span> parameter contains the
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opaque data specified to the <a class="xref" href="repstart.html" title="DB_ENV->rep_start()">DB_ENV->rep_start()</a>
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<span class="bold"><strong>cdata</strong></span> parameter. The application should
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take whatever action is needed to establish a communication channel with this new
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environment.
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</p>
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</li>
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<li>
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<p><a id="repmsg_DB_REP_NOTPERM"></a>
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<span class="bold"><strong>DB_REP_NOTPERM</strong></span>
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</p>
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<p>
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The <code class="methodname">DB_ENV->rep_process_message()</code> method will return
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<code class="literal">DB_REP_NOTPERM</code> if a message carrying a
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<a class="link" href="reptransport.html#transport_DB_REP_PERMANENT">DB_REP_PERMANENT</a>
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flag was processed successfully, but was not written to disk. The LSN of this
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record is returned. The application should take whatever action is deemed
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necessary to retain its recoverability characteristics.
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</p>
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</li>
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</ul>
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</div>
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<p>
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Unless otherwise specified, the <code class="methodname">DB_ENV->rep_process_message()</code>
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<span>
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<span>
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method returns a non-zero error value on failure and 0 on success.
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</span>
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</span>
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</p>
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<div class="sect2" lang="en" xml:lang="en">
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<div class="titlepage">
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<div>
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<div>
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<h3 class="title"><a id="idp62025392"></a>Parameters</h3>
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</div>
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</div>
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</div>
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<div class="sect3" lang="en" xml:lang="en">
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<div class="titlepage">
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<div>
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<div>
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<h4 class="title"><a id="idp62024488"></a>control</h4>
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</div>
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</div>
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</div>
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<p>
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The <span class="bold"><strong>control</strong></span> parameter should
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reference a copy of the <span class="bold"><strong>control</strong></span>
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parameter specified by Berkeley DB on the sending environment.
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See the <a class="xref" href="reptransport.html" title="DB_ENV->rep_set_transport()">DB_ENV->rep_set_transport()</a> method for more information.
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</p>
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</div>
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<div class="sect3" lang="en" xml:lang="en">
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<div class="titlepage">
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<div>
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<div>
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<h4 class="title"><a id="idp62032312"></a>rec</h4>
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</div>
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</div>
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</div>
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<p>
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The <span class="bold"><strong>rec</strong></span> parameter should reference a
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copy of the <span class="bold"><strong>rec</strong></span> parameter specified
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by Berkeley DB on the sending environment.
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See the <a class="xref" href="reptransport.html" title="DB_ENV->rep_set_transport()">DB_ENV->rep_set_transport()</a> method for more information.
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</p>
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</div>
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<div class="sect3" lang="en" xml:lang="en">
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<div class="titlepage">
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<div>
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<div>
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<h4 class="title"><a id="idp62033760"></a>envid</h4>
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</div>
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</div>
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</div>
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<p>
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The <span class="bold"><strong>envid</strong></span> parameter should contain
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the local identifier that corresponds to the environment that sent the
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message to be processed (see <a href="../../programmer_reference/rep_id.html" class="olink">Replication environment IDs</a> for more
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information).
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</p>
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</div>
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<div class="sect3" lang="en" xml:lang="en">
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<div class="titlepage">
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<div>
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<div>
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<h4 class="title"><a id="idp62036440"></a>ret_lsnp</h4>
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</div>
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</div>
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</div>
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<p>
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If <code class="methodname">DB_ENV->rep_process_message()</code> method returns
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<code class="literal">DB_REP_NOTPERM</code> then the
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<span class="bold"><strong>ret_lsnp</strong></span> parameter will contain the log sequence
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number of this permanent log message that could not be written to disk. If
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<code class="methodname">DB_ENV->rep_process_message()</code> method returns
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<code class="literal">DB_REP_ISPERM</code> then the
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<span class="bold"><strong>ret_lsnp</strong></span> parameter will contain largest log
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sequence number of the permanent records that are now written to disk as a
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result of processing this message. In all other cases the value of
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<span class="bold"><strong>ret_lsnp</strong></span> is undefined.
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</p>
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</div>
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</div>
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<div class="sect2" lang="en" xml:lang="en">
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<div class="titlepage">
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<div>
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<div>
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<h3 class="title"><a id="idp62020456"></a>Errors</h3>
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</div>
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</div>
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</div>
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<p>
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The <code class="methodname">DB_ENV->rep_process_message()</code>
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<span>
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<span>
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method may fail and return one of the following non-zero errors:
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</span>
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</span>
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</p>
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<div class="sect3" lang="en" xml:lang="en">
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<div class="titlepage">
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<div>
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<div>
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<h4 class="title"><a id="idp62042088"></a>EINVAL</h4>
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</div>
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</div>
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</div>
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<p>
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If the database environment was not already configured to
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communicate with a replication group by a call to
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<a class="xref" href="reptransport.html" title="DB_ENV->rep_set_transport()">DB_ENV->rep_set_transport()</a>;
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if the database environment was not already opened;
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if this method is called from a Replication Manager
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application; or if an invalid flag value or parameter
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was specified.
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</p>
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</div>
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</div>
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<div class="sect2" lang="en" xml:lang="en">
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<div class="titlepage">
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<div>
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<div>
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<h3 class="title"><a id="idp62042944"></a>Class</h3>
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</div>
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</div>
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</div>
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<p>
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<a class="link" href="env.html" title="Chapter 5. The DB_ENV Handle">DB_ENV</a>
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</p>
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</div>
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<div class="sect2" lang="en" xml:lang="en">
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<div class="titlepage">
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<div>
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<div>
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<h3 class="title"><a id="idp62044728"></a>See Also</h3>
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</div>
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</div>
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</div>
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<p>
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<a class="xref" href="rep.html#replist" title="Replication and Related Methods">Replication and Related Methods</a>
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</p>
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</div>
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</div>
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<div class="navfooter">
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<hr />
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<table width="100%" summary="Navigation footer">
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<tr>
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<td width="40%" align="left"><a accesskey="p" href="repget_timeout.html">Prev</a> </td>
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<td width="20%" align="center">
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<a accesskey="u" href="rep.html">Up</a>
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</td>
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<td width="40%" align="right"> <a accesskey="n" href="repclockskew.html">Next</a></td>
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</tr>
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<tr>
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<td width="40%" align="left" valign="top">DB_ENV->rep_get_timeout() </td>
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<td width="20%" align="center">
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<a accesskey="h" href="index.html">Home</a>
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</td>
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<td width="40%" align="right" valign="top"> DB_ENV->rep_set_clockskew()</td>
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</tr>
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</table>
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</div>
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</body>
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</html>
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