Subscribing to an Event

Scenarios

This section describes how to configure SMN to obtain server status information of cloud applications, such as creation, startup, shutdown, restarting, deletion, recomposing, upgrading, as well as image creation, and report the information to Cloud Trace Service (CTS) to improve the APS access speed and operation accuracy.

Procedure

Configuring a subscription event

1. Enable CTS.
   

   When CTS is enabled, a system tracker is automatically created. You can use this tracker.

2. Create an SMN topic.
3. Add a subscription.
4. Configure key event notifications.
   

   Configure parameters for key event notifications as follows:

   • Notification name: This parameter is user-defined, for example, keyOperate_WorkspaceAPP.
   • Operation type: Select Custom. In the operation list, set Select Service to WorkspaceAPP, Select Resource to server or session, and Select Operation to createServer, rebootServer, startServer, stopServer, deleteServer, reinstallServer, changeServerImage, createServerImage, sessionConnect, sessionDisconnect, or sessionLogout.
   • User: not specified.
   • Notification: yes.
   • Topic: Select the topic created in 2.

Verifying the subscription event

• When a cloud server is successful or fails to be created, started, shut down, restarted, deleted, recomposed, or upgraded, an image is successful or fails to be created, or a session is connected, disconnected, or logged out, the system automatically reports an event to CTS. You will receive a message based on the protocol configured in 3. For example, if you select email, you will receive a notification email.

• You can also view all traces on the CTS console.

5. Log in to the console.

6. Expand the service list and choose Management & Governance > Cloud Trace Service.
7. On the Trace List page, set Trace Source to WorkspaceAPP, Resource Type to server or session, and search by Trace Name. The trace name is shown in Table 1.

   Table 1 Types of events that can be traced

   Operation	Resource Type	Trace Name
   Creating a server	server	createServer
   Deleting a server	server	deleteServer
   Shutting down a server	server	stopServer
   Starting a server	server	startServer
   Restarting a server	server	rebootServer
   Creating an image	server	createServerImage
   Upgrading an image	server	changeServerImage
   Reinstalling a server	server	reinstallServer
   Session connection	session	sessionConnect
   Session disconnection	session	sessionDisconnect
   Session logout	session	sessionLogout

8. Press Enter to query the result.
9. Take stopping a cloud server as an example. View Trace Overview of the event. The status is BEGIN, as shown in Figure 1.
   Figure 1 Starting to stop the server.
   

10. View Trace Overview of the stopping event. The server is stopped, as shown in Figure 2.
    Figure 2 Stopping the server successfully
    
    

    • When server creation or deletion fails, a failure trace is reported. In the trace details, the value of Message is FAIL.
    • If a server is powered off or not shut down on the homepage of the Workspace client, it is shut down abnormally. In this case, the BEGIN message is not reported in CTS. Only the message indicating that the server has been shut down will be reported.
    • Three minutes after the server is started, if the login status is not Ready on the server management page, a failure trace is reported. In the trace details, the value of Message is FAIL.
    • Three minutes after the server is shut down, if the login status is not Stopped on the server management page, a failure trace is reported. In the trace details, the value of Message is FAIL.