Notifications

Configure Notifications

About this task

For the service to work correctly in GE Digital APM, you must configure the Notification Service by modifying the file Meridium.Service.Notification.exe.config on all GE Digital APM Servers.

Procedure

  1. On the GE Digital APM Server, navigate to the folder where the Notification Service files are installed. If you installed the software in the default location, you can locate these files in the folder C:\Program Files\Meridium\Services.
  2. In an application that you can use to modify XML script (e.g., Notepad), open the file Meridium.Service.Notification.exe.config.
  3. Depending on the type of server to which you want to relay the messages, modify the script within the <notification> and the <system.serviceModel> tags.
    Note: The complexity of a Notification Service lies in its configuration. Notification Servers can relay messages to two types of servers - apm server (web server) and external server. The entire configuration of the external service needs to be represented by an end point, and the end point name needs to have a wcf end point configuration.
  4. Save and close the file.
  5. Start or restart the Notification Service.

About Notifications

A notification is a message exchange pattern in which a requestor sends a request message to a replier system. The replier system receives and processes the request. It is an effective and powerful messaging pattern configured to relay messages.

Notifications provides an automated means of triggering notices about subscribed services and objects across different messaging channels. Messages are triggered when the application services and objects to which a user has subscribed change.

Whenever the GE Digital APM user logs in to the application and makes any change to the metadata, the change triggers the API to send a message or a notification to the notification service. The notification service then looks up the targets who need to be notified of this change and sends the notification in the protocol of their choice. The primary idea of a notification is to inform other services that there is a change. It does not have any control over what services do with that information. Notification service also knows the contents of the message relayed.

The notification process proceeds as follows:

  1. When a GE Digital APM Server is configured and made available to users, in the file Web.config, the URL <add key="notificationServiceUrl" value="net.tcp://{0}/meridium/Service/Notification" /> informs the website of the location of its notification service.
  2. When GE Digital APM comes up or opens, in the Web.config file, it replaces the {0} parameter in the URL above with the server name of the local host. The notification service has to be read in on every physical server of every web application.
  3. The GE Digital APM installation installs the service Meridium Notification service. Notification service is then configured to replicate and relay any messages.

For example, assume that, in GE Digital APM, you have configured a notification service that sends out a notification whenever a change is made to any entity. If a change is made to the Security Groups Information and the changes are saved, then the web service sends a message to the notification service that an entity is updated. Then, the notification service relays that message to any other servers that are configured to receive the message.