blob: b35435dfe3f3bfd980d565f2372a47b492defe4b [file] [log] [blame]
<?xml version="1.0"?>
Licensed to the Apache Software Foundation (ASF) under one
or more contributor license agreements. See the NOTICE file
distributed with this work for additional information
regarding copyright ownership. The ASF licenses this file
to you under the Apache License, Version 2.0 (the
"License"); you may not use this file except in compliance
with the License. You may obtain a copy of the License at
Unless required by applicable law or agreed to in writing,
software distributed under the License is distributed on an
KIND, either express or implied. See the License for the
specific language governing permissions and limitations
under the License.
<section xmlns="" version="5.0" xml:id="Java-Broker-Concepts-Virtualhosts">
<para>A virtualhost is a namespace in which messaging is performed. Virtualhosts are independent;
the messaging that goes on within one virtualhost is independent of any messaging that goes on
in another virtualhost. For instance, a queue named <emphasis>foo</emphasis> defined in one
virtualhost is completely independent of a queue named <emphasis>foo</emphasis> in another
<para>A virtualhost is identified by a name which must be unique broker-wide. Clients use the name
to identify the virtualhost to which they wish to connect when they connect.</para>
<para>A virtualhost exists in a container called a virtualhost node.</para>
<para>The virtualhost comprises a number of entities. This section summaries the purpose of
each of the entities and describes the relationships between them. These details are developed
further in the sub-sections that follow.</para>
<para><emphasis>Exchanges</emphasis> is a named entity within the Virtual Host which receives
messages from producers and routes them to matching Queues.</para>
<para><emphasis>Queues</emphasis> are named entities that hold messages for delivery to consumer
<para><emphasis>Bindings</emphasis> are relationships between Exchanges and Queue that facilitate
routing of messages from the Exchange to the Queue.</para>
<para><emphasis>Connections</emphasis> represent a live connection to the virtualhost from a
messaging client.</para>
<para>A <emphasis>Session</emphasis> represents a context for the production or consumption of
messages. A Connection can have many Sessions.</para>
<para>A <emphasis>Consumer</emphasis> represents a live consumer that is attached to queue.</para>
<para><emphasis>Loggers</emphasis> are responsible for producing logs for this virtualhost.</para>
<para> The following diagram depicts the Virtualhost model: <figure>
<title>Virtualhost Model showing major entities</title>
<imagedata fileref="images/VirtualHost-Model.png" format="PNG" scalefit="1"/>
<phrase>Virtual Host Model</phrase>
<para>A <emphasis>virtualhost</emphasis> is backed by storage which is used to store the