rep_transport.html   [plain text]


<!--$Id: rep_transport.html,v 1.1.1.1 2003/02/15 04:55:54 zarzycki Exp $-->
<!--Copyright 1997-2002 by Sleepycat Software, Inc.-->
<!--All rights reserved.-->
<!--See the file LICENSE for redistribution information.-->
<html>
<head>
<title>Berkeley DB: DbEnv.set_rep_transport</title>
<meta name="description" content="Berkeley DB: An embedded database programmatic toolkit.">
<meta name="keywords" content="embedded,database,programmatic,toolkit,b+tree,btree,hash,hashing,transaction,transactions,locking,logging,access method,access methods,java,C,C++">
</head>
<body bgcolor=white>
<a name="2"><!--meow--></a>
<table width="100%"><tr valign=top>
<td>
<h1>DbEnv.set_rep_transport</h1>
</td>
<td align=right>
<a href="../api_java/c_index.html"><img src="../images/api.gif" alt="API"></a><a href="../reftoc.html"><img src="../images/ref.gif" alt="Ref"></a>
</td></tr></table>
<hr size=1 noshade>
<tt>
<h3><pre>
import com.sleepycat.db.*;
<p>
public interface DbEnvSend
{
    public abstract int db_send(DB_ENV *dbenv,
      const Dbt *control, const Dbt *rec, int envid, int flags);
}
public class DbEnv
{
    public int set_rep_transport(DbEnvSend db_send)
	throws DbException;
    ...
}
</pre></h3>
<h1>Description</h1>
<p>The DbEnv.set_rep_transport method initializes the communication infrastructure
for a database environment participating in a replicated application.
<p>The <b>envid</b> parameter is the local environment's ID.  It must be
a positive integer and uniquely identify this Berkeley DB database environment
(see <a href="../ref/rep/id.html">Replication environment IDs</a> for more
information).
<p>The <b>send</b> parameter is a callback interface used to transmit data
using the replication application's communication infrastructure.  The
parameters to <b>send</b> are as follows:
<p><dl compact>
<p><dt>dbenv<dd>The enclosing database environment.
<p><dt>control<dd>The control parameter is the first of the two data elements to be
transmitted by the <b>send</b> interface.
<p><dt>rec<dd>The rec parameter is the second of the two data elements to be
transmitted by the <b>send</b> interface.
<p><dt>envid<dd>The <b>envid</b> parameter is a positive integer identifier that
specifies the replication environment to which the message should be
sent (see <a href="../ref/rep/id.html">Replication environment IDs</a> for
more information).
<p><a name="3"><!--meow--></a>
The special identifier Db.DB_EID_BROADCAST indicates that a message
should be broadcast to every environment in the replication group.  The
application may use a true broadcast protocol, or may send the message
in sequence to each machine with which it is in communication.
<p><dt>flags<dd>
<p>The <b>flags</b> value must be set to 0 or by bitwise inclusively <b>OR</b>'ing together one or
more of the following values:
<p><dl compact>
<p><dt><a name="Db.DB_REP_PERMANENT">Db.DB_REP_PERMANENT</a><dd>The record being sent is critical for maintaining database integrity
(for example, the message includes a transaction commit).  The
application should take appropriate action to enforce the reliability
guarantees it has chosen, such as waiting for acknowledgement from one
or more clients.
</dl>
</dl>
<p>The <b>send</b> interface must return 0 on success and non-zero on
failure.  If the <b>send</b> interface fails, the message being sent
is necessary to maintain database integrity, and the local log is not
configured for synchronous flushing, the local log will be flushed;
otherwise, any error from the <b>send</b> interface will be ignored.
<p>It may sometimes be useful to pass application-specific data to the
<b>send</b> interface; see <a href="../ref/env/faq.html">Environment
FAQ</a> for a discussion on how to do this.
<p>The DbEnv.set_rep_transport method configures operations performed using the specified
<a href="../api_java/env_class.html">DbEnv</a> handle, not all operations performed on the underlying
database environment.
<p>The DbEnv.set_rep_transport interface may be called at any time during the life of
the application.
<p>The DbEnv.set_rep_transport method throws an exception that encapsulates a non-zero error value on
failure.
<h1>Errors</h1>
<p>The DbEnv.set_rep_transport method may fail and throw an exception for errors specified for other Berkeley DB and C library or system methods.
If a catastrophic error has occurred, the DbEnv.set_rep_transport method may fail and
throw a <a href="../api_java/runrec_class.html">DbRunRecoveryException</a>,
in which case all subsequent Berkeley DB calls will fail in the same way.
<h1>Class</h1>
<a href="../api_java/env_class.html">DbEnv</a>
<h1>See Also</h1>
<a href="../api_java/rep_list.html">Replication and Related Methods</a>
</tt>
<table width="100%"><tr><td><br></td><td align=right>
<a href="../api_java/c_index.html"><img src="../images/api.gif" alt="API"></a><a href="../reftoc.html"><img src="../images/ref.gif" alt="Ref"></a>
</td></tr></table>
<p><font size=1><a href="http://www.sleepycat.com">Copyright Sleepycat Software</a></font>
</body>
</html>