Edit File - File Manager

Edit File: rep_transport.html

<html>
<head>
<title>Berkeley DB: DbEnv::rep_set_transport</title>
<meta name="description" content="Berkeley DB: An embedded database programmatic toolkit.">
<meta name="keywords" content="embedded,database,programmatic,toolkit,btree,hash,hashing,transaction,transactions,locking,logging,access method,access methods,Java,C,C++">
</head>
<body bgcolor=white>
<table width="100%"><tr valign=top>
<td>
DbEnv::rep_set_transport
</td>
<td align=right>
<a href="../../db4-devel-4.7.25/api_cxx/api_core.html"><img src="../../db4-devel-4.7.25/images/api.gif" alt="API"></a>
<a href="../../db4-devel-4.7.25/ref/toc.html"><img src="../../db4-devel-4.7.25/images/ref.gif" alt="Ref"></a></td>
</tr></table>
<hr size=1 noshade>
<tt>
<pre>
#include &lt;db_cxx.h&gt;

int
DbEnv::rep_set_transport(int envid,
 int (*send)(DB_ENV *dbenv,
 const Dbt *control, const Dbt *rec, const DbLsn *lsnp,
 int envid, u_int32_t flags));
</pre>
<hr size=1 noshade>
Description: DbEnv::rep_set_transport
The DbEnv::rep_set_transport method initializes the communication infrastructure
for a database environment participating in a replicated application.
The DbEnv::rep_set_transport method is not called by most replication
applications. It should only be called by applications implementing
their own network transport layer, explicitly holding replication group
elections and handling replication messages outside of the replication
manager framework.
The DbEnv::rep_set_transport method configures operations performed using the specified
<a href="../../db4-devel-4.7.25/api_cxx/env_class.html">DbEnv</a> handle, not all operations performed on the underlying
database environment.
The DbEnv::rep_set_transport method may be called at any time during the life of the
application.
The DbEnv::rep_set_transport method
either returns a non-zero error value
or throws an exception that encapsulates a non-zero error value on
failure, and returns 0 on success.

Parameters 
 envid<ul compact><li>The envid parameter is the local environment's ID. It must be
a non-negative integer and uniquely identify this Berkeley DB database environment
(see <a href="../../db4-devel-4.7.25/ref/rep/id.html">Replication environment IDs</a> for more
information).</ul>
 send<ul compact><li>The send callback function is used to transmit data using the
replication application's communication infrastructure. The parameters
to send are as follows:
 
dbenv<ul compact><li>The dbenv parameter is the enclosing database environment handle.</ul>
control<ul compact><li>The control parameter is the first of the two data elements to be
transmitted by the send function.</ul>
rec<ul compact><li>The rec parameter is the second of the two data elements to be
transmitted by the send function.</ul>
lsnp<ul compact><li>If the type of message to be sent has an LSN associated with it, then
the lsnp parameter contains the LSN of the record being sent.
This LSN can be used to determine that certain records have been
processed successfully by clients.</ul>
envid<ul compact><li>The envid parameter is a positive integer identifier that
specifies the replication environment to which the message should be
sent (see <a href="../../db4-devel-4.7.25/ref/rep/id.html">Replication environment IDs</a> for
more information).
The special identifier 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. In both
cases, the sending site should not be asked to process the message.
The special identifier <a href="../../db4-devel-4.7.25/ref/rep/id.html#DB_EID_INVALID">DB_EID_INVALID</a> indicates an invalid
environment ID. This may be used to initialize values that are
subsequently checked for validity.</ul>
flags<ul compact><li>The flags parameter must be set to 0 or by bitwise inclusively OR'ing together one
or more of the following values:
 
<a name="DB_REP_ANYWHERE">DB_REP_ANYWHERE</a><ul compact><li>The message is a client request that can be satisfied by another client
as well as by the master.</ul>
<a name="DB_REP_NOBUFFER">DB_REP_NOBUFFER</a><ul compact><li>The record being sent should be transmitted immediately and not buffered
or delayed.</ul>
<a name="DB_REP_PERMANENT">DB_REP_PERMANENT</a><ul compact><li>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.</ul>
<a name="DB_REP_REREQUEST">DB_REP_REREQUEST</a><ul compact><li>The message is a client request that has already been made and to which
no response was received.</ul>
 </ul>
 
It may sometimes be useful to pass application-specific data to the
send function; see <a href="../../db4-devel-4.7.25/ref/env/faq.html">Environment
FAQ</a> for a discussion on how to do this.
The send function must return 0 on success and non-zero on
failure. If the send function 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 send function will be ignored.
Berkeley DB is not re-entrant. Callback functions should not attempt to make
library calls (for example, to release locks or close open handles).
Re-entering Berkeley DB is not guaranteed to work correctly, and the results
are undefined.</ul>
 
 Errors
The DbEnv::rep_set_transport method
may fail and throw
<a href="../../db4-devel-4.7.25/api_cxx/except_class.html">DbException</a>,
encapsulating one of the following non-zero errors, or return one of
the following non-zero errors:
 
EINVAL<ul compact><li>An
invalid flag value or parameter was specified.</ul>
 
<hr size=1 noshade>
 Class
<a href="../../db4-devel-4.7.25/api_cxx/env_class.html">DbEnv</a>
 See Also
<a href="../../db4-devel-4.7.25/api_cxx/rep_list.html">Replication and Related Methods</a>
</tt>
<table width="100%"><tr><td> </td><td align=right>
<a href="../../db4-devel-4.7.25/api_cxx/api_core.html"><img src="../../db4-devel-4.7.25/images/api.gif" alt="API"></a><a href="../../db4-devel-4.7.25/ref/toc.html"><img src="../../db4-devel-4.7.25/images/ref.gif" alt="Ref"></a>
</td></tr></table>
Copyright (c) 1996,2008 Oracle. All rights reserved.
</body>
</html>

Back to File Manager