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diff --git a/lib/orber/doc/src/ch_orber_kernel.xml b/lib/orber/doc/src/ch_orber_kernel.xml new file mode 100644 index 0000000000..6669641432 --- /dev/null +++ b/lib/orber/doc/src/ch_orber_kernel.xml @@ -0,0 +1,102 @@ +<?xml version="1.0" encoding="latin1" ?> +<!DOCTYPE chapter SYSTEM "chapter.dtd"> + +<chapter> + <header> + <copyright> + <year>1999</year><year>2009</year> + <holder>Ericsson AB. All Rights Reserved.</holder> + </copyright> + <legalnotice> + The contents of this file are subject to the Erlang Public License, + Version 1.1, (the "License"); you may not use this file except in + compliance with the License. You should have received a copy of the + Erlang Public License along with this software. If not, it can be + retrieved online at http://www.erlang.org/. + + Software distributed under the License is distributed on an "AS IS" + basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See + the License for the specific language governing rights and limitations + under the License. + + </legalnotice> + + <title>The Orber Application</title> + <prepared></prepared> + <docno></docno> + <date>1998-10-05</date> + <rev></rev> + <file>ch_orber_kernel.xml</file> + </header> + + <section> + <title>ORB Kernel and IIOP </title> + <p>This chapter gives a brief overview of the ORB and its relation + to objects in a distributed environment and the usage of Domains + in Orber. + Also Internet-Inter ORB Protocol (<term id="IIOP"><termdef>Internet-Inter ORB Protocol</termdef></term>) is discussed and how this + protocol facilitates communication between ORBs to + allow the accessory of persistent server objects in Erlang. </p> + </section> + + <section> + <title>The Object Request Broker (ORB)</title> + <p>An ORB kernel can be best described as the middle-ware, which + creates relationships between clients and servers, but is + defined by its interfaces. This allows transparency for the + user, as they do not have to be aware of where the requested + object is located. Thus, the programmer can work with any other + platform provided that an IDL mapping and interfaces exist. + </p> + <p>The IDL mapping which is described in a later chapter is the + translator between other platforms, and languages. However, it + is the ORB, which provides objects with a structure by which + they can communicate with other objects. + </p> + <p>ORBs intercept and direct messages from one object, pass this + message using IIOP to another ORB, which then directs the + message to the indicated object. + </p> + <p>An ORB is the base on which interfaces, communication stubs + and mapping can be built to enable communication between + objects. Orber uses <term id="domains"><termdef>A domain allows a more efficient communication protocol to be used between objects not on the same node without the need of an ORB</termdef></term>to group objects of different nodes + </p> + <p>How the ORB provides communication is shown very simply in figure 1 below: </p> + <marker id="theORB"></marker> + <image file="theORB.gif"> + <icaption> +Figure 1: How the Object Request Broker works.</icaption> + </image> + <p>The domain in Orber gives an extra aspect to the distributed object + environment as each domain has one ORB, but it is distributed over + a number of object in different nodes. The domain binds objects on + nodes more closely than distributed objects in different domains. The + advantage of a domain is that a faster communication exists between + nodes and objects of the same domain. An internal communication protocol + (other than IIOP) allows a + more efficient communication between these objects. </p> + <note> + <p>Unlike objects, domains can only have one name + so that no communication ambiguities exist between domains.</p> + </note> + </section> + + <section> + <title>Internet Inter-Object Protocol (IIOP)</title> + <p>IIOP is a communication protocol developed by the OMG to + facilitate communication in a distributed object-oriented + environment. + </p> + <p>Figure 2 below demonstrates how IIOP works between objects:</p> + <marker id="iiop"></marker> + <image file="iiop.gif"> + <icaption> +Figure 2: IIOP communication between domains and objects.</icaption> + </image> + <note> + <p>Within the Orber domains the objects communicate without + using the IIOP. However, the user is unaware of the difference in protocols, as this difference is not visible. </p> + </note> + </section> +</chapter> + |