<?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>Log file limits</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="log.html" title="Chapter 16. The Logging Subsystem" /> <link rel="prev" href="log_config.html" title="Configuring logging" /> <link rel="next" href="mp.html" title="Chapter 17. The Memory Pool Subsystem" /> </head> <body> <div class="navheader"> <table width="100%" summary="Navigation header"> <tr> <th colspan="3" align="center">Log file limits</th> </tr> <tr> <td width="20%" align="left"><a accesskey="p" href="log_config.html">Prev</a> </td> <th width="60%" align="center">Chapter 16. The Logging Subsystem </th> <td width="20%" align="right"> <a accesskey="n" href="mp.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="log_limits"></a>Log file limits</h2> </div> </div> </div> <p>Log filenames and sizes impose a limit on how long databases may be used in a Berkeley DB database environment. It is quite unlikely that an application will reach this limit; however, if the limit is reached, the Berkeley DB environment's databases must be dumped and reloaded.</p> <p>The log filename consists of <span class="bold"><strong>log.</strong></span> followed by 10 digits, with a maximum of 2,000,000,000 log files. Consider an application performing 6000 transactions per second for 24 hours a day, logged into 10MB log files, in which each transaction is logging approximately 500 bytes of data. The following calculation:</p> <pre class="programlisting">(10 * 2^20 * 2000000000) / (6000 * 500 * 365 * 60 * 60 * 24) = ~221</pre> <p>indicates that the system will run out of log filenames in roughly 221 years.</p> <p>There is no way to reset the log filename space in Berkeley DB. If your application is reaching the end of its log filename space, you must do the following:</p> <div class="orderedlist"> <ol type="1"> <li>Archive your databases as if to prepare for catastrophic failure (see <a class="xref" href="transapp_archival.html" title="Database and log file archival">Database and log file archival</a> for more information).</li> <li>Reset the database's log sequence numbers (see the <span class="bold"><strong>-r</strong></span> option to the <a href="../api_reference/C/db_load.html" class="olink">db_load utility</a> for more information).</li> <li>Remove all of the log files from the database environment. (This is the only situation in which all the log files are removed from an environment; in all other cases, at least a single log file is retained.)</li> <li>Restart your application.</li> </ol> </div> </div> <div class="navfooter"> <hr /> <table width="100%" summary="Navigation footer"> <tr> <td width="40%" align="left"><a accesskey="p" href="log_config.html">Prev</a> </td> <td width="20%" align="center"> <a accesskey="u" href="log.html">Up</a> </td> <td width="40%" align="right"> <a accesskey="n" href="mp.html">Next</a></td> </tr> <tr> <td width="40%" align="left" valign="top">Configuring logging </td> <td width="20%" align="center"> <a accesskey="h" href="index.html">Home</a> </td> <td width="40%" align="right" valign="top"> Chapter 17. The Memory Pool Subsystem </td> </tr> </table> </div> </body> </html>