1<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" 2 "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"> 3<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" 4 "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> 5 6<html xmlns="http://www.w3.org/1999/xhtml"> 7 <head> 8 <meta name="generator" content="HTML Tidy, see www.w3.org" /> 9 10 <title>Server Pool Management</title> 11 </head> 12 <!-- Background white, links blue (unvisited), navy (visited), red (active) --> 13 14 <body bgcolor="#FFFFFF" text="#000000" link="#0000FF" 15 vlink="#000080" alink="#FF0000"> 16 <div align="CENTER"> 17 <img src="images/sub.gif" alt="[APACHE DOCUMENTATION]" /> 18 19 <h3>Apache HTTP Server</h3> 20 </div> 21 22 23 24 <h1 align="CENTER">Server Pool Management</h1> 25 <hr /> 26 27 <p>We found that many people were using values for "MaxServers" 28 either too high or too low, and were hanging themselves on it. 29 The model we adopted is still based on long-lived 30 minimal-forking processes, but instead of specifying one number 31 of persistent processes, the web-master specifies a maximum and 32 minimum number of processes to be "spare" - every couple of 33 seconds the parent checks the actual number of spare servers 34 and adjusts accordingly. This should keep the number of servers 35 concurrently running relatively low while still ensuring 36 minimal forking.</p> 37 38 <p>We renamed the current StartServers to MinSpareServers, 39 created separate StartServers parameter which means what it 40 says, and renamed MaxServers to MaxSpareServers (though the old 41 name still works, for NCSA 1.4 back-compatibility). The old 42 names were generally regarded as too confusing.</p> 43 44 <p>The defaults for each variable are:</p> 45<pre> 46MinSpareServers 5 47MaxSpareServers 10 48StartServers 5 49</pre> 50 There is an absolute maximum number of simultaneous children 51 defined by a compile-time limit which defaults to 256 and a 52 "MaxClients" directive which specifies the number of 53 simultaneous children that will be allowed. MaxClients can be 54 adjusted up to the compile-time limit (HARD_SERVER_LIMIT, 55 defined in httpd.h). If you need more than 256 simultaneous 56 children, you need to modify both HARD_SERVER_LIMIT and 57 MaxClients. 58 59 <p>In versions before 1.2, HARD_SERVER_LIMIT defaulted to 60 150.</p> 61 62 <p>We do not recommend changing either of these values 63 unless:</p> 64 65 <ol> 66 <li>You know you have the server resources to handle 67 more</li> 68 69 <li>You use the machine for other purposes and must limit the 70 amount of memory Apache uses</li> 71 </ol> 72 <hr /> 73 74 <h3 align="CENTER">Apache HTTP Server</h3> 75 <a href="./"><img src="images/index.gif" alt="Index" /></a> 76 77 </body> 78</html> 79 80 81 82