Nirvana Enterprise Manager - Channel Administration

Introduction

This section describes the process of creating a Nirvana channel on Nirvana realm servers. Channels are the logical rendezvous point for data that is published and subscribed. If you are using Nirvana JMS then channels are the equivalent of JMS topics.

Each channel that is created consists of a physical channel within the Nirvana realm as well as it's logical reference within a namespace that may be made up of resources that exist across multiple Nirvana realm servers. Creating channels using the Enterprise Manager creates the physical object within the realm. Once created, references to channels can be obtained using the Nirvana Client and Admin APIs. Channels can also be monitored and managed using the Enterprise Manager.

When you connect to a Nirvana realm in the Enterprise Manager, all channels, queues and services found within the realm namespace are displayed in a tree structure under the realm node itself. It is possible to view multiple Nirvana relms servers fom a single enterprise manager instance.

Creating Channels on a Nirvana Realm

To create new Nirvana channels, the Enterprise Manager provides a number of options. Firstly, in order to create a channel, the branch where the channel will exist needs to be selected within the namespace tree.

For example, to create a channel called /eur/rates on a Nirvana realm called 'productionmaster' simply right-click on the realm node to display a pop-up menu which contains a 'Create Channel' option.

After selecting 'Create Channel', an Add channel dialog box appears. Channels have a set of attributes assigned to them when they are created. The create channel dialog allows you to input values for each of these attributes.

In order to create the channel '/eur/rates' please fill in the name and choose the channel type as well as any other attributes. In the example below a TTL of 7 seconds has been given to the channel.

Clicking on the 'OK' button will create the channel /eur/rates on the Nirvana realm 'productionmaster' and render the channel object in the namespace tree of the Enterprise Manager underneath the realm node. This is shown in the image below.

As you can see from the image above, the channel node in the tree has been created under a folder (which we call a container node) called /eur under the realm 'productionmaster'.

It is also possible to create channels directly underneath container nodes. For example, if we wished to create another channel called /eur/trades, we could repeat the process described above using the full absolute name of the channel. This would again create a channel called trades under the container node /eur. Alternatively, we can select the /eur node and create the new channel using its relative name /trades. Selecting the container node and right-clicking on the node, shows another pop-up menu of options for container nodes. One of the menu is 'Create Channel'. The image below shows this menu as it appears when the container is right-clicked.

By selecting the menu item, 'Create Channel' from the container node, you are once again presented with the create channel dialog. This dialog looks like the dialog used previously, except the title of the dialog shows that the channel will be created under the container /eur, as shown in the image below.