1<?xml version="1.0" encoding="UTF-8" standalone="no"?> 2<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> 3<html xmlns="http://www.w3.org/1999/xhtml"> 4 <head> 5 <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /> 6 <title>Release 4.2: Client replication environments</title> 7 <link rel="stylesheet" href="gettingStarted.css" type="text/css" /> 8 <meta name="generator" content="DocBook XSL Stylesheets V1.73.2" /> 9 <link rel="start" href="index.html" title="Berkeley DB Programmer's Reference Guide" /> 10 <link rel="up" href="upgrade_4_2_toc.html" title="Chapter 39. Upgrading Berkeley DB 4.1 applications to Berkeley DB 4.2" /> 11 <link rel="prev" href="upgrade_4_2_repinit.html" title="Release 4.2: Replication" /> 12 <link rel="next" href="upgrade_4_2_tcl.html" title="Release 4.2: Tcl API" /> 13 </head> 14 <body> 15 <div class="navheader"> 16 <table width="100%" summary="Navigation header"> 17 <tr> 18 <th colspan="3" align="center">Release 4.2: Client replication environments</th> 19 </tr> 20 <tr> 21 <td width="20%" align="left"><a accesskey="p" href="upgrade_4_2_repinit.html">Prev</a> </td> 22 <th width="60%" align="center">Chapter 39. Upgrading Berkeley DB 4.1 applications to Berkeley DB 4.2</th> 23 <td width="20%" align="right"> <a accesskey="n" href="upgrade_4_2_tcl.html">Next</a></td> 24 </tr> 25 </table> 26 <hr /> 27 </div> 28 <div class="sect1" lang="en" xml:lang="en"> 29 <div class="titlepage"> 30 <div> 31 <div> 32 <h2 class="title" style="clear: both"><a id="upgrade_4_2_nosync"></a>Release 4.2: Client replication environments</h2> 33 </div> 34 </div> 35 </div> 36 <p>In previous Berkeley DB releases, replication clients always behaved as if 37<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 38not write or synchronously flush their log when receiving a transaction 39commit or prepare message. However, applications needing a high level 40of transactional guarantee may need a write and synchronous flush on 41the client. By default in the Berkeley DB 4.2 release, client database 42environments write and synchronously flush their logs when receiving a 43transaction commit or prepare message. Applications not needing such 44a high level of transactional guarantee should use the environment's 45<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 46environments to not do the write or flush on transaction commit, as this 47will increase their performance. Regardless of the setting of the 48<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 49transaction prepare.</p> 50 </div> 51 <div class="navfooter"> 52 <hr /> 53 <table width="100%" summary="Navigation footer"> 54 <tr> 55 <td width="40%" align="left"><a accesskey="p" href="upgrade_4_2_repinit.html">Prev</a> </td> 56 <td width="20%" align="center"> 57 <a accesskey="u" href="upgrade_4_2_toc.html">Up</a> 58 </td> 59 <td width="40%" align="right"> <a accesskey="n" href="upgrade_4_2_tcl.html">Next</a></td> 60 </tr> 61 <tr> 62 <td width="40%" align="left" valign="top">Release 4.2: Replication </td> 63 <td width="20%" align="center"> 64 <a accesskey="h" href="index.html">Home</a> 65 </td> 66 <td width="40%" align="right" valign="top"> Release 4.2: Tcl API</td> 67 </tr> 68 </table> 69 </div> 70 </body> 71</html> 72