Simple Message Queue (formerly MNS):OSS event notification

Scenarios

• If you authorize other users to perform operations on your OSS buckets and want to be notified when these operations occur, you can create an event notification rule.

• You can analyze data based on event notifications, view the number of times for which an operation occurs within a period of time, and analyze the recent development trend of your business. You can also import event notifications into other services for analysis, such as E-MapReduce (EMR).

• You can monitor the metrics such as QPS of operations that are performed on your OSS resources based on event notifications.

Events

Message format

The message content of an OSS event notification is encoded in Base64. The decoded content is in the JSON format. The following sample code provides an example of the decoded message content.

{
    "events":[
        {
            "eventName":"ObjectDownloaded:GetObject",
            "eventSource":"acs:oss",
            "eventTime":"2016-07-01T11:17:30.000Z",
            "eventVersion":"1.0",
            "oss":{
                "bucket":{
                    "arn":"acs:oss:cn-shenzhen:123456789098****:event-notification-test-shenzhen",
                    "name":"event-notification-test-shenzhen",
                    "ownerIdentity":"123456789098****"
                },
                "object":{
                    "deltaSize":0,
                    "eTag":"0CC175B9C0F1B6A831C399E26977****",
                    "key":"test",
                    "readFrom":0,
                    "readTo":1,
                    "size":1
                },
                "ossSchemaVersion":"1.0",
                "ruleId":"GetObjectRule"
            },
            "region":"cn-shenzhen",
            "requestParameters":{
                "sourceIPAddress":"140.205.XX.XX"
            },
            "responseElements":{
                "requestId":"5776514AF09A9E654242****"
            },
            "userIdentity":{
                "principalId":"123456789098****"
            },
            "xVars":{
                "x:callback-var1":"value1",
                "x:vallback-var2":"value2"
            }
        }
    ]
}

The following table describes the parameters in the message content.

Usage notes

• It takes approximately 10 minutes for a new event notification rule to take effect.

• The system automatically creates a topic for an event notification rule, and you may be charged for the created topic. For more information, see Billing overview.

• You can create or delete event notification rules. However, you cannot modify an event notification rule.

(Optional) Step 1: Create a queue

To subscribe to a queue to receive messages from downstream clients, you need to create a queue. You can also create a subscription after event notification rule is created.

1. Log on to the SMQ console.

2. In the left-side navigation pane, choose Queue Model > Queues.

3. In the top navigation bar, select a region.

4. On the Queues page, click Create Queue.

5. In the Create Queue panel, configure the following parameters and click OK:

   • Name: the name of the queue.

   • Maximum Message Length: the maximum length of the message that is sent to the queue.

   • Long Polling Period: the maximum duration for which long polling requests are held after the ReceiveMessage operation is called.

   • Visibility Timeout Period: the duration for which a message stays in the Inactive state after the message is received from the queue.

   • Message Retention Period: the maximum duration for which a message exists in the queue. After the specified retention period, the message is deleted regardless of whether the message is received.

   • Message Delay Period: the period after which all messages sent to the queue are consumed.

   • Enable Logging Feature: specifies whether to enable the logging feature.

   After the queue is created, it is displayed on the Queues page.

(Optional) Step 2: Create a bucket

If the desired bucket already exists, skip this step.

1. Log on to the OSS console.

2. In the left-side navigation pane, click Buckets.

3. On the Buckets page, click Create Bucket.

4. In the Create Bucket panel, configure the following parameters and click Create.

   • Bucket Name: the name of the bucket. In this example, event-notification-test is used.

   • Region: the region in which the bucket resides. The region must be the same as the region in which the queue resides.

   • Block Public Access: specifies whether to block public access. In this example, this feature is disabled.

   • ACL: specifies the permissions on the bucket. In this example, Public Read/Write is selected.

     Note

     Use the default values of other parameters.

Step 3: Create an event notification rule

After an event notification rule is created, SMQ automatically creates a topic for the rule and creates a subscription to the topic with the specified endpoint. You can view and manage topics and subscriptions in the SMQ console.

1. Log on to the SMQ console.

2. In the left-side navigation pane, click Event Notifications.

3. In the top navigation bar, select a region.

4. On the OSS tab of the Event Notifications page, click Create Rule.

5. In the Create Rule - OSS panel, configure the following parameters and click OK.

   • Name: Enter a name for the rule.

   • Event Type: Select one or more event types.

   • Match Mode: Configure the match mode for the rule.

     Note

     Match modes include Full Name, Prefix, Suffix, and Prefix & Suffix. Two match modes cannot have intersections. OSS resources include buckets and objects. Their names are separated with forward slashes (/). Example: movie/hello.avi.

     • Full Name: movie/hello.avi.

     • Prefix:

       • movie/hello indicates all objects with a prefix of hello in the movie bucket.

       • movie/ indicates all objects in the movie bucket.

       • mov indicates all objects in the buckets with a prefix of mov.

     • Suffix: avi indicates all objects with a suffix of .avi in all buckets.

     • Prefix & Suffix: A combination of the movie/ prefix and the .avi suffix indicates all objects with a suffix of .avi in the movie bucket.

   • Receiving Terminal: Select Queue from the drop-down list and enter the name of the queue that you created in Step 1.

Step 4: Upload an object

1. Log on to the OSS console.

2. In the left-side navigation pane, click Buckets.

3. On the Buckets page, click the name of the OSS bucket that you want to manage to go to the Object Management page.

4. Click Upload Object above the object list. >

5. On the page that appears, configure the parameters and click Upload Object. For more information about the parameters, see the Use the OSS console section of the "Simple upload" topic.

   The Task List panel appears. On the Upload Tasks tab, the state of the object is displayed as Uploaded.

Step 5: Receive messages

1. Log on to the SMQ console.

2. In the left-side navigation pane, choose Queue Model > Queues.

3. In the top navigation bar, select a region.

4. On the Queues page, find the queue that you want to manage and choose More > Send Messages in the Action column.

5. In the Receive Message section of the Quick Experience page, click Receive Message.

   A list of messages appears in the Receive Message section.

6. In the message list, find the message that you want to view and click Details in the Actions column. In the Message Details dialog box, view the message content.