88 lines
6.5 KiB
HTML
88 lines
6.5 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="Example: Use the basic concepts of DDM in an APPN network" />
|
||
|
|
<meta name="abstract" content="The Advanced Peer-to-Peer Networking (APPN) support of an iSeries server can be used to allow DDM access to systems not directly connected to the local server." />
|
||
|
|
<meta name="description" content="The Advanced Peer-to-Peer Networking (APPN) support of an iSeries server can be used to allow DDM access to systems not directly connected to the local server." />
|
||
|
|
<meta name="DC.subject" content="concepts, basic, example in APPN network, advanced peer-to-peer networking (APPN), description, APPN (advanced peer-to-peer networking), networking, description of APPN, communications, APPN" />
|
||
|
|
<meta name="keywords" content="concepts, basic, example in APPN network, advanced peer-to-peer networking (APPN), description, APPN (advanced peer-to-peer networking), networking, description of APPN, communications, APPN" />
|
||
|
|
<meta name="DC.Relation" scheme="URI" content="rbae5partfile.htm" />
|
||
|
|
<meta name="copyright" content="(C) Copyright IBM Corporation 1999, 2006" />
|
||
|
|
<meta name="DC.Rights.Owner" content="(C) Copyright IBM Corporation 1999, 2006" />
|
||
|
|
<meta name="DC.Format" content="XHTML" />
|
||
|
|
<meta name="DC.Identifier" content="rbae5xappn1" />
|
||
|
|
<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>Example: Use the basic concepts of DDM in an APPN network</title>
|
||
|
|
</head>
|
||
|
|
<body id="rbae5xappn1"><a name="rbae5xappn1"><!-- --></a>
|
||
|
|
<!-- Java sync-link --><script language="Javascript" src="../rzahg/synch.js" type="text/javascript"></script>
|
||
|
|
<h1 class="topictitle1">Example: Use the basic concepts of DDM in an APPN network</h1>
|
||
|
|
<div><p>The Advanced
|
||
|
|
Peer-to-Peer Networking<sup>®</sup> (APPN) support of an <span class="keyword">iSeries™ server</span> can
|
||
|
|
be used to allow DDM access to systems not directly connected to the local
|
||
|
|
server.</p>
|
||
|
|
<div class="example"> <div class="fignone" id="rbae5xappn1__rbae5appn1"><a name="rbae5xappn1__rbae5appn1"><!-- --></a><span class="figcap">Figure 1. Use DDM in an APPN
|
||
|
|
network</span><br /><div class="imageleft"><img src="rsll116.gif" alt="This figure is described in the text of this section." /></div><br /></div>
|
||
|
|
</div>
|
||
|
|
<div class="section"><p>Figure 1 in <a href="rbae5dirrel1.htm#rbae5dirrel1">Example: Use the basic concepts of DDM in an APPC network</a> shows
|
||
|
|
a program on the Chicago server accessing a file on the New York server. Although
|
||
|
|
the servers are shown as directly connected, the same DDM concepts apply if
|
||
|
|
the network is configured as shown in the preceding figure. When the DDM file
|
||
|
|
CUST021 in the figure is opened on the Chicago server, the APPN support finds
|
||
|
|
the remote location named NEWYORK, determines the optimal path through the
|
||
|
|
network, and establishes a DDM conversation with that location. Although there
|
||
|
|
might be several other servers (network nodes) forwarding the data between
|
||
|
|
CHICAGO and NEWYORK, the source DDM and target DDM function as if there were
|
||
|
|
a direct connection between these two servers.</p>
|
||
|
|
</div>
|
||
|
|
<div class="section"><p>If the file CUSTMAST were moved from NEWYORK to some other server
|
||
|
|
in the network (for example, DALLAS), then in this example, the DDM file at
|
||
|
|
CHICAGO needs to be changed. The remote location name would be changed from
|
||
|
|
NEWYORK to DALLAS. If a large number of servers in the network refer to the
|
||
|
|
file CUSTMAST, then movement of the file results in a change to the DDM file
|
||
|
|
at each of these servers. By using the <span class="keyword">iSeries</span> capability
|
||
|
|
to have multiple local location names, maintenance of these files is reduced.</p>
|
||
|
|
</div>
|
||
|
|
<div class="section"><p>In the preceding figure, the server NEWYORK can be given two local
|
||
|
|
location names, NEWYORK and FILELOC. The DDM file at CHICAGO uses FILELOC
|
||
|
|
as the remote location name. When access to file CUSTMAST is required, APPN
|
||
|
|
finds the location FILELOC in the system named NEWYORK, and the DDM conversation
|
||
|
|
is established as before.</p>
|
||
|
|
</div>
|
||
|
|
<div class="section"><p>If the file CUSTMAST is now moved from NEWYORK to DALLAS, the
|
||
|
|
user at NEWYORK deletes the local location FILELOC from his server, and it
|
||
|
|
is added to the server at DALLAS. This is done by using the APPN local location
|
||
|
|
list. When the program in CHICAGO now attempts to access the file CUSTMAST,
|
||
|
|
the APPN support finds the remote location FILELOC at the server in Dallas,
|
||
|
|
and the DDM conversation is established to that server. The movement of CUSTMAST
|
||
|
|
did not result in a change to the DDM file at CHICAGO.</p>
|
||
|
|
</div>
|
||
|
|
<div class="section"><p>This example shows the concept of multiple local locations and
|
||
|
|
how reduced maintenance results when files are moved from one server to another.
|
||
|
|
The example is not intended to suggest that a unique location name should
|
||
|
|
be used for every file accessed through DDM. The decision of which files should
|
||
|
|
be associated with separate local locations should be based on such factors
|
||
|
|
as the movement of these files and the number of remote servers accessing
|
||
|
|
these files.</p>
|
||
|
|
</div>
|
||
|
|
</div>
|
||
|
|
<div>
|
||
|
|
<div class="familylinks">
|
||
|
|
<div class="parentlink"><strong>Parent topic:</strong> <a href="rbae5partfile.htm" title="A system object with type *FILE exists on the source server to identify a remote file. It combines the characteristics of a device file and a database file. As a device file, the DDM file refers to a remote location name, local location name, device name, mode, and a remote network ID to identify a remote server as the target server. The DDM file appears to the application program as a database file and serves as the access device between a source server program and a remote file.">Parts of DDM: DDM file</a></div>
|
||
|
|
</div>
|
||
|
|
</div>
|
||
|
|
</body>
|
||
|
|
</html>
|