Subscribing to GaussDB(DWS) Cluster Events

GuassDB(DWS) uses the Simple Message Notification (SMN) service to send notifications of GuassDB(DWS) events. The SMN function is only available by subscription. In a subscription, you need to specify one or more event filtering conditions. When an event that matches all filtering conditions occurs, GuassDB(DWS) sends a notification based on the subscription. The filter conditions include the Event Type (for example, Management, Monitoring, or Security), Event Severity (for example, Normal or Warning), and Event Source Category (for example, Cluster or Snapshot).

Figure 1 shows the basic process architecture of event subscription. After subscribing to GaussDB(DWS) event notifications, you will receive notifications by text message, email, or application when management, monitoring, or security events occur in a specific cluster or snapshot.

Figure 1 Event subscription architecture
Click to enlarge

Prerequisites

Before creating a subscription, you have created a notification topic. For details, see "Topic Management" > "Creating a Topic" in the Simple Message Notification User Guide.

Creating a Subscription

Log in to the DWS console.
In the navigation pane on the left, choose Dedicated Clusters > Management > Events.
On the Events page, click the Subscriptions tab and then Create Subscription.

In the Subscription Settings area, set basic subscription information and event filtering conditions.

The Subscribed Event area displays the events filtered by the system based on the subscription settings.

Figure 2 Subscription Settings
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**Table 1** Subscription parameters
Parameter	Description
Notification	Enable or disable event subscription. After notification is disabled, the system stops sending notifications of subscribed events but does not delete the subscription.
Subscription Name	Enter the name of a subscription. The name can contain letters (upper or lower case), digits, hyphens (-), and underscores (_) and must start with a letter or digit. The name must be between 1 and 256 characters in length.
Event Type	Select the type of the event to be subscribed. Possible values are Management, Monitoring, and Security.
Event Severity	Select the alarm severity of the event. Possible values are Normal and Warning.
Event Source Category	Select the event source category: cluster, snapshot,.

Select an SMN topic from the Message Notification Topic drop-down list.
- The selected topic must have granted GaussDB(DWS) the permission to publish messages to the topic.
  If GaussDB(DWS) has not been authorized to publish messages to the selected topic, go to the topic management page of the SMN console to configure topic authorization. For details, see Topic Management > Configuring Topic Policies in the Simple Message Notification User Guide. When configuring the topic policy, select GaussDB(DWS) for Services that can publish messages to this topic.
- To create a topic, click Create Topic. The SMN console is displayed. For details, see Topic Management > Creating a Topic in the Simple Message Notification User Guide.
Click OK to complete the subscription.

Modifying the Subscription

On the GaussDB(DWS) console, choose Dedicated Clusters > Management. On the displayed page, click the Subscriptions tab.
Locate the row that contains a specified subscription and click Edit in the Operation column.
On the Edit Subscription page, modify parameters by referring to 4 to 6.

Deleting the Subscription

On the GaussDB(DWS) console, choose Dedicated Clusters > Management. On the displayed page, click the Subscriptions tab.
Locate the row that contains a specified subscription and click Delete in the Operation column.
In the displayed dialog box, click Yes to delete the subscription.