74 lines
4.8 KiB
HTML
74 lines
4.8 KiB
HTML
|
<?xml version="1.0" encoding="UTF-8"?>
|
||
|
|
<!DOCTYPE html
|
||
|
|
PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
|
||
|
|
<html lang="en-us" xml:lang="en-us">
|
||
|
|
<head>
|
||
|
|
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
|
||
|
|
<meta name="security" content="public" />
|
||
|
|
<meta name="Robots" content="index,follow" />
|
||
|
|
<meta http-equiv="PICS-Label" content='(PICS-1.1 "http://www.icra.org/ratingsv02.html" l gen true r (cz 1 lz 1 nz 1 oz 1 vz 1) "http://www.rsac.org/ratingsv01.html" l gen true r (n 0 s 0 v 0 l 0) "http://www.classify.org/safesurf/" l gen true r (SS~~000 1))' />
|
||
|
|
<meta name="DC.Type" content="reference" />
|
||
|
|
<meta name="DC.Title" content="Multithreaded server recommendations" />
|
||
|
|
<meta name="abstract" content="When you write a typical server to take advantage of threads, a common design is to have a single listener thread waiting for client requests and multiple individual worker threads to perform the client's requested operations." />
|
||
|
|
<meta name="description" content="When you write a typical server to take advantage of threads, a common design is to have a single listener thread waiting for client requests and multiple individual worker threads to perform the client's requested operations." />
|
||
|
|
<meta name="DC.Relation" scheme="URI" content="rzahwpcoco.htm" />
|
||
|
|
<meta name="copyright" content="(C) Copyright IBM Corporation 1998, 2006" />
|
||
|
|
<meta name="DC.Rights.Owner" content="(C) Copyright IBM Corporation 1998, 2006" />
|
||
|
|
<meta name="DC.Format" content="XHTML" />
|
||
|
|
<meta name="DC.Identifier" content="rzahwser-serco" />
|
||
|
|
<meta name="DC.Language" content="en-us" />
|
||
|
|
<!-- All rights reserved. Licensed Materials Property of IBM -->
|
||
|
|
<!-- US Government Users Restricted Rights -->
|
||
|
|
<!-- Use, duplication or disclosure restricted by -->
|
||
|
|
<!-- GSA ADP Schedule Contract with IBM Corp. -->
|
||
|
|
<link rel="stylesheet" type="text/css" href="./ibmdita.css" />
|
||
|
|
<link rel="stylesheet" type="text/css" href="./ic.css" />
|
||
|
|
<title>Multithreaded server recommendations</title>
|
||
|
|
</head>
|
||
|
|
<body id="rzahwser-serco"><a name="rzahwser-serco"><!-- --></a>
|
||
|
|
<!-- Java sync-link --><script language="Javascript" src="../rzahg/synch.js" type="text/javascript"></script>
|
||
|
|
<h1 class="topictitle1">Multithreaded server recommendations</h1>
|
||
|
|
<div><p>When you write a typical server to take advantage of threads, a
|
||
|
|
common design is to have a single listener thread waiting for client requests
|
||
|
|
and multiple individual worker threads to perform the client's requested operations.</p>
|
||
|
|
<div class="section"><p>Creating threads should not use very many resources. However,
|
||
|
|
because some servers require a faster response time to clients, some server
|
||
|
|
application programs maintain a pool of worker threads that are waiting for
|
||
|
|
work. They do this to avoid creating new threads.</p>
|
||
|
|
</div>
|
||
|
|
<div class="section"><p>Typically, the worker threads use some synchronization primitive
|
||
|
|
to wait for client processing requests. Instead of creating a new thread to
|
||
|
|
process each client request, the listener thread queues the client request
|
||
|
|
and signals the waiting worker threads. The signal sometimes uses variables.</p>
|
||
|
|
</div>
|
||
|
|
<div class="section"><p>A server application is commonly considered trusted with the data
|
||
|
|
that it serves to clients. Because the server is running multithreaded applications,
|
||
|
|
you must consider some issues concerning the activities it performs:</p>
|
||
|
|
<ul><li>You should not call user application code from a multithreaded server.
|
||
|
|
To run user application code safely from a multithreaded server, the user
|
||
|
|
application code must follow the same strict rules that the original multithreaded
|
||
|
|
server did. These rules concern the actions that it can take and the application
|
||
|
|
programming interfaces (APIs) that it can call </li>
|
||
|
|
<li>As you should with any other part of your application, you must evaluate
|
||
|
|
the processing that is required to fulfill the client request for its thread
|
||
|
|
safety.</li>
|
||
|
|
<li>Processing on behalf of the client might affect process-level
|
||
|
|
resources of the server in a way that is not wanted for the server. For example,
|
||
|
|
changing the coded character set identifier (CCSID) so that data representation
|
||
|
|
is the same as that of the client also affects other threads in the job. CCSID
|
||
|
|
is a job resource.</li>
|
||
|
|
<li>A server can change the security information (user profile and group profile)
|
||
|
|
of a worker thread to make it become the client that is being served. However,
|
||
|
|
when the server does this, you need to consider what resources the threads
|
||
|
|
share. The worker thread has access to all the already opened job level resources
|
||
|
|
that more privileged users in the same job might have created or opened. </li>
|
||
|
|
</ul>
|
||
|
|
</div>
|
||
|
|
</div>
|
||
|
|
<div>
|
||
|
|
<div class="familylinks">
|
||
|
|
<div class="parentlink"><strong>Parent topic:</strong> <a href="rzahwpcoco.htm" title="There are several performance considerations for multithreaded jobs on i5/OS.">Performance considerations in multithreaded applications</a></div>
|
||
|
|
</div>
|
||
|
|
</div>
|
||
|
|
</body>
|
||
|
|
</html>
|