<?xml version="1.0" encoding="UTF-8" standalone="no"?> <!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"> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /> <title>Release 4.2: Client replication environments</title> <link rel="stylesheet" href="gettingStarted.css" type="text/css" /> <meta name="generator" content="DocBook XSL Stylesheets V1.73.2" /> <link rel="start" href="index.html" title="Berkeley DB Programmer's Reference Guide" /> <link rel="up" href="upgrade_4_2_toc.html" title="Chapter 39. Upgrading Berkeley DB 4.1 applications to Berkeley DB 4.2" /> <link rel="prev" href="upgrade_4_2_repinit.html" title="Release 4.2: Replication" /> <link rel="next" href="upgrade_4_2_tcl.html" title="Release 4.2: Tcl API" /> </head> <body> <div class="navheader"> <table width="100%" summary="Navigation header"> <tr> <th colspan="3" align="center">Release 4.2: Client replication environments</th> </tr> <tr> <td width="20%" align="left"><a accesskey="p" href="upgrade_4_2_repinit.html">Prev</a> </td> <th width="60%" align="center">Chapter 39. Upgrading Berkeley DB 4.1 applications to Berkeley DB 4.2</th> <td width="20%" align="right"> <a accesskey="n" href="upgrade_4_2_tcl.html">Next</a></td> </tr> </table> <hr /> </div> <div class="sect1" lang="en" xml:lang="en"> <div class="titlepage"> <div> <div> <h2 class="title" style="clear: both"><a id="upgrade_4_2_nosync"></a>Release 4.2: Client replication environments</h2> </div> </div> </div> <p>In previous Berkeley DB releases, replication clients always behaved as if <a href="../api_reference/C/envset_flags.html#envset_flags_DB_TXN_NOSYNC" class="olink">DB_TXN_NOSYNC</a> behavior was configured, that is, clients would not write or synchronously flush their log when receiving a transaction commit or prepare message. However, applications needing a high level of transactional guarantee may need a write and synchronous flush on the client. By default in the Berkeley DB 4.2 release, client database environments write and synchronously flush their logs when receiving a transaction commit or prepare message. Applications not needing such a high level of transactional guarantee should use the environment's <a href="../api_reference/C/envset_flags.html#envset_flags_DB_TXN_NOSYNC" class="olink">DB_TXN_NOSYNC</a> flag to configure their client database environments to not do the write or flush on transaction commit, as this will increase their performance. Regardless of the setting of the <a href="../api_reference/C/envset_flags.html#envset_flags_DB_TXN_NOSYNC" class="olink">DB_TXN_NOSYNC</a> flag, clients will always write and flush on transaction prepare.</p> </div> <div class="navfooter"> <hr /> <table width="100%" summary="Navigation footer"> <tr> <td width="40%" align="left"><a accesskey="p" href="upgrade_4_2_repinit.html">Prev</a> </td> <td width="20%" align="center"> <a accesskey="u" href="upgrade_4_2_toc.html">Up</a> </td> <td width="40%" align="right"> <a accesskey="n" href="upgrade_4_2_tcl.html">Next</a></td> </tr> <tr> <td width="40%" align="left" valign="top">Release 4.2: Replication </td> <td width="20%" align="center"> <a accesskey="h" href="index.html">Home</a> </td> <td width="40%" align="right" valign="top"> Release 4.2: Tcl API</td> </tr> </table> </div> </body> </html>