1<?xml version="1.0" encoding="ISO-8859-1"?> 2<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"> 3<html xmlns="http://www.w3.org/1999/xhtml" lang="en" xml:lang="en"><head><!-- 4 XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX 5 This file is generated from xml source: DO NOT EDIT 6 XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX 7 --> 8<title>File Descriptor Limits - Apache HTTP Server</title> 9<link href="/style/css/manual.css" rel="stylesheet" media="all" type="text/css" title="Main stylesheet" /> 10<link href="/style/css/manual-loose-100pc.css" rel="alternate stylesheet" media="all" type="text/css" title="No Sidebar - Default font size" /> 11<link href="/style/css/manual-print.css" rel="stylesheet" media="print" type="text/css" /><link rel="stylesheet" type="text/css" href="/style/css/prettify.css" /> 12<script src="/style/scripts/prettify.js" type="text/javascript"> 13</script> 14 15<link href="/images/favicon.ico" rel="shortcut icon" /></head> 16<body id="manual-page" class="no-sidebar"><div id="page-header"> 17<p class="menu"><a href="/mod/">Modules</a> | <a href="/mod/directives.html">Directives</a> | <a href="http://wiki.apache.org/httpd/FAQ">FAQ</a> | <a href="/glossary.html">Glossary</a> | <a href="/sitemap.html">Sitemap</a></p> 18<p class="apache">Apache HTTP Server Version 2.2</p> 19<img alt="" src="/images/feather.gif" /></div> 20<div class="up"><a href="./"><img title="<-" alt="<-" src="/images/left.gif" /></a></div> 21<div id="path"> 22<a href="http://www.apache.org/">Apache</a> > <a href="http://httpd.apache.org/">HTTP Server</a> > <a href="http://httpd.apache.org/docs/">Documentation</a> > <a href="../">Version 2.2</a> > <a href="./">Virtual Hosts</a></div><div id="page-content"><div id="preamble"><h1>File Descriptor Limits</h1> 23<div class="toplang"> 24<p><span>Available Languages: </span><a href="/en/vhosts/fd-limits.html" title="English"> en </a> | 25<a href="/fr/vhosts/fd-limits.html" hreflang="fr" rel="alternate" title="Fran�ais"> fr </a> | 26<a href="/ja/vhosts/fd-limits.html" hreflang="ja" rel="alternate" title="Japanese"> ja </a> | 27<a href="/ko/vhosts/fd-limits.html" hreflang="ko" rel="alternate" title="Korean"> ko </a> | 28<a href="/tr/vhosts/fd-limits.html" hreflang="tr" rel="alternate" title="T�rk�e"> tr </a></p> 29</div> 30 31 32 <p>When using a large number of Virtual Hosts, Apache may run 33 out of available file descriptors (sometimes called <cite>file 34 handles</cite>) if each Virtual Host specifies different log 35 files. The total number of file descriptors used by Apache is 36 one for each distinct error log file, one for every other log 37 file directive, plus 10-20 for internal use. Unix operating 38 systems limit the number of file descriptors that may be used 39 by a process; the limit is typically 64, and may usually be 40 increased up to a large hard-limit.</p> 41 42 <p>Although Apache attempts to increase the limit as required, 43 this may not work if:</p> 44 45 <ol> 46 <li>Your system does not provide the <code>setrlimit()</code> 47 system call.</li> 48 49 <li>The <code>setrlimit(RLIMIT_NOFILE)</code> call does not 50 function on your system (such as Solaris 2.3)</li> 51 52 <li>The number of file descriptors required exceeds the hard 53 limit.</li> 54 55 <li>Your system imposes other limits on file descriptors, 56 such as a limit on stdio streams only using file descriptors 57 below 256. (Solaris 2)</li> 58 </ol> 59 60 <p>In the event of problems you can:</p> 61 62 <ul> 63 <li>Reduce the number of log files; don't specify log files 64 in the <code class="directive"><a href="/mod/core.html#virtualhost"><VirtualHost></a></code> 65 sections, but only log to the main log files. (See <a href="#splitlogs">Splitting up your log files</a>, below, for more 66 information on doing this.)</li> 67 68 <li> 69 If you system falls into 1 or 2 (above), then increase the 70 file descriptor limit before starting Apache, using a 71 script like 72 73 <div class="example"><p><code> 74 <code>#!/bin/sh<br /> 75 ulimit -S -n 100<br /> 76 exec httpd</code> 77 </code></p></div> 78 </li> 79 </ul> 80 81</div> 82<div class="top"><a href="#page-header"><img alt="top" src="/images/up.gif" /></a></div> 83<div class="section"> 84<h2><a name="splitlogs" id="splitlogs">Splitting up your log files</a></h2> 85 86<p>If you want to log multiple virtual hosts to the same log file, you 87may want to split up the log files afterwards in order to run 88statistical analysis of the various virtual hosts. This can be 89accomplished in the following manner.</p> 90 91<p>First, you will need to add the virtual host information to the log 92entries. This can be done using the <code class="directive"><a href="/mod/mod_log_config.html# logformat"> 93LogFormat</a></code> 94directive, and the <code>%v</code> variable. Add this to the beginning 95of your log format string:</p> 96 97<div class="example"><p><code> 98LogFormat "%v %h %l %u %t \"%r\" %>s %b" vhost<br /> 99CustomLog logs/multiple_vhost_log vhost 100</code></p></div> 101 102<p>This will create a log file in the common log format, but with the 103canonical virtual host (whatever appears in the 104<code class="directive"><a href="/mod/core.html#servername">ServerName</a></code> directive) prepended to 105each line. (See <code class="directive"><a href="/mod/mod_log_config.html#custom log formats">Custom Log Formats</a></code> for 106more about customizing your log files.)</p> 107 108<p>When you wish to split your log file into its component parts (one 109file per virtual host) you can use the program <code><a href="/programs/other.html">split-logfile</a></code> to accomplish 110this. You'll find this program in the <code>support</code> directory 111of the Apache distribution.</p> 112 113<p>Run this program with the command:</p> 114 115<div class="example"><p><code> 116split-logfile < /logs/multiple_vhost_log 117</code></p></div> 118 119<p>This program, when run with the name of your vhost log file, will 120generate one file for each virtual host that appears in your log file. 121Each file will be called <code>hostname.log</code>.</p> 122 123</div></div> 124<div class="bottomlang"> 125<p><span>Available Languages: </span><a href="/en/vhosts/fd-limits.html" title="English"> en </a> | 126<a href="/fr/vhosts/fd-limits.html" hreflang="fr" rel="alternate" title="Fran�ais"> fr </a> | 127<a href="/ja/vhosts/fd-limits.html" hreflang="ja" rel="alternate" title="Japanese"> ja </a> | 128<a href="/ko/vhosts/fd-limits.html" hreflang="ko" rel="alternate" title="Korean"> ko </a> | 129<a href="/tr/vhosts/fd-limits.html" hreflang="tr" rel="alternate" title="T�rk�e"> tr </a></p> 130</div><div class="top"><a href="#page-header"><img src="/images/up.gif" alt="top" /></a></div><div class="section"><h2><a id="comments_section" name="comments_section">Comments</a></h2><div class="warning"><strong>Notice:</strong><br />This is not a Q&A section. 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