1<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> 2 3<html> 4 <head> 5 <meta name="generator" content="HTML Tidy, see www.w3.org"> 6 <title>Spool Queue Processing</title> 7 <meta name="GENERATOR" content= 8 "Modular DocBook HTML Stylesheet Version 1.7"> 9 <link rel="HOME" title=" LPRng Reference Manual" href= 10 "index.htm"> 11 <link rel="UP" title="Job Processing" href="jobsteps.htm"> 12 <link rel="PREVIOUS" title="Job Reception " href= 13 "reception.htm"> 14 <link rel="NEXT" title="Opening the Output Device " href= 15 "opendevice.htm"> 16 </head> 17 18 <body class="SECT1" bgcolor="#FFFFFF" text="#000000" link= 19 "#0000FF" vlink="#840084" alink="#0000FF"> 20 <div class="NAVHEADER"> 21 <table summary="Header navigation table" width="100%" border= 22 "0" cellpadding="0" cellspacing="0"> 23 <tr> 24 <th colspan="3" align="center">LPRng Reference Manual: 5 25 Sep 2003 (For LPRng-3.8.22)</th> 26 </tr> 27 28 <tr> 29 <td width="10%" align="left" valign="bottom"><a href= 30 "reception.htm" accesskey="P">Prev</a></td> 31 32 <td width="80%" align="center" valign="bottom">Chapter 33 15. Job Processing</td> 34 35 <td width="10%" align="right" valign="bottom"><a href= 36 "opendevice.htm" accesskey="N">Next</a></td> 37 </tr> 38 </table> 39 <hr align="LEFT" width="100%"> 40 </div> 41 42 <div class="SECT1"> 43 <h1 class="SECT1"><a name="SPOOLQ">15.4. Spool Queue 44 Processing</a></h1> 45 46 <p>Options used:</p> 47 48 <ul> 49 <li> 50 <p><var class="LITERAL">lpd_force_poll=</var><span class= 51 "emphasis"><i class="EMPHASIS">Force <b class= 52 "APPLICATION">lpd</b> to periodically poll print 53 queues</i></span></p> 54 </li> 55 56 <li> 57 <p><var class="LITERAL">lpd_poll_time=</var><span class= 58 "emphasis"><i class="EMPHASIS">Time between 59 polls</i></span></p> 60 </li> 61 62 <li> 63 <p><var class="LITERAL">max_servers_active=</var><span 64 class="emphasis"><i class="EMPHASIS">Maximum number of 65 active servers</i></span></p> 66 </li> 67 </ul> 68 <br> 69 <br> 70 71 <p>When the <b class="APPLICATION">lpd</b> server starts, it 72 will fork a set of subserver processes, each which will 73 handle an individual queue.</p> 74 75 <p>If a system has a large number of queues, then this 76 forking operation may result in the <b class= 77 "APPLICATION">lpd</b> server exhausting the process 78 resources. To control this, the <var class= 79 "LITERAL">max_servers_active</var> value restricts the number 80 of active children to the specified value. If this value is 81 0, then 50% of the maximum system processes value will be 82 used.</p> 83 84 <p>Due to the limits on the number of processes, there may be 85 times when a job is placed in a queue, but the <b class= 86 "APPLICATION">lpd</b> server is unable to start handling the 87 job. When all of the children of the main <b class= 88 "APPLICATION">lpd</b> server have exited, the server starts a 89 timer. After <var class="LITERAL">lpd_poll_time</var> 90 seconds, it will scan the queues, looking for jobs to 91 process, and starts a process to service them. If it does not 92 find any jobs it remains idle.</p> 93 94 <p>The <var class="LITERAL">lpd_force_poll</var> flag causes 95 the server to periodically poll the queues. This is useful 96 when there is a high possibility that jobs could fail to be 97 printed due to high loads on the server.</p> 98 </div> 99 100 <div class="NAVFOOTER"> 101 <hr align="LEFT" width="100%"> 102 103 <table summary="Footer navigation table" width="100%" border= 104 "0" cellpadding="0" cellspacing="0"> 105 <tr> 106 <td width="33%" align="left" valign="top"><a href= 107 "reception.htm" accesskey="P">Prev</a></td> 108 109 <td width="34%" align="center" valign="top"><a href= 110 "index.htm" accesskey="H">Home</a></td> 111 112 <td width="33%" align="right" valign="top"><a href= 113 "opendevice.htm" accesskey="N">Next</a></td> 114 </tr> 115 116 <tr> 117 <td width="33%" align="left" valign="top">Job 118 Reception</td> 119 120 <td width="34%" align="center" valign="top"><a href= 121 "jobsteps.htm" accesskey="U">Up</a></td> 122 123 <td width="33%" align="right" valign="top">Opening the 124 Output Device</td> 125 </tr> 126 </table> 127 </div> 128 </body> 129</html> 130 131