64 lines
4.0 KiB
HTML
64 lines
4.0 KiB
HTML
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<?xml version="1.0" encoding="UTF-8"?>
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<!DOCTYPE html
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PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
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<html lang="en-us" xml:lang="en-us">
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<head>
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<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
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<meta name="DC.Type" content="reference" />
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<meta name="DC.Title" content="Introduction to client/server performance" />
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<meta name="abstract" content="The performance characteristics of a client/server environment are different than those of centralized environments." />
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<meta name="description" content="The performance characteristics of a client/server environment are different than those of centralized environments." />
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<meta name="DC.Relation" scheme="URI" content="rzaikperftuneodbc.htm" />
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<meta name="copyright" content="(C) Copyright IBM Corporation 1999, 2006" />
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<meta name="DC.Rights.Owner" content="(C) Copyright IBM Corporation 1999, 2006" />
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<meta name="DC.Identifier" content="introcsperf" />
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<!-- All rights reserved. Licensed Materials Property of IBM -->
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<!-- US Government Users Restricted Rights -->
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<!-- GSA ADP Schedule Contract with IBM Corp. -->
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<link rel="stylesheet" type="text/css" href="./ibmdita.css" />
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<link rel="stylesheet" type="text/css" href="./ic.css" />
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<title>Introduction to client/server performance</title>
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</head>
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<body id="introcsperf"><a name="introcsperf"><!-- --></a>
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<!-- Java sync-link --><script language="Javascript" src="../rzahg/synch.js" type="text/javascript"></script>
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<h1 class="topictitle1">Introduction to client/server performance</h1>
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<div><p>The performance characteristics of a client/server environment
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are different than those of centralized environments.</p>
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<div class="section"><p>This is because client/server applications are split
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between the client and the server. The client and server communicate by sending
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and receiving requests and messages. This model is far different than that
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for a centralized environment. In that environment, a program calls the CPU,
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and the memory and disk drives are fully dedicated.</p>
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</div>
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<div class="section"><p>Instead, when a client requests processing time and data from
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the server, it transmits the request on the network. The request travels to
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the server and waits in a queue until the server is able to process it. The
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performance characteristics of this type of architecture degrade exponentially
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as the number of requests increase. In other words, response times increase
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gradually as more requests are made, but then increase dramatically at some
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point, which is known as the "knee of the curve." This concept is illustrated
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by the following graph:</p>
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</div>
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<div class="section"><br /><img src="perf01.gif" alt="Client/server performance curve" /><br /></div>
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<div class="section"><p>It is important to determine this point at which performance begins
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to degrade significantly. The point can vary with every client/server installation.</p>
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</div>
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<div class="section"><p>The following is a suggested guideline for client/server operations: <em>Communicate
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with the server only when necessary, and in as few data transmissions as possible.</em> Opening
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a file and reading one record at a time often results in problems for client-server
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projects and tools.</p>
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</div>
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</div>
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<div>
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<div class="familylinks">
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<div class="parentlink"><strong>Parent topic:</strong> <a href="rzaikperftuneodbc.htm" title="A key consideration for ODBC application developers is achieving maximum performance from client/server applications.">Performance-tuning iSeries Access for Windows ODBC</a></div>
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</div>
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</div>
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</body>
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</html>
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