ApsaraMQ for MQTT:Migrate clients from open source MQTT brokers to ApsaraMQ for MQTT brokers

Limits

If a client is migrated from an open source EMQX broker, the original system topics cannot be used. For example, you cannot use topics whose names start with a dollar sign ($), such as $delayed and $share.

Step 1: Create ApsaraMQ for MQTT resources

Create an instance

1. Log on to the ApsaraMQ for MQTT console. In the left-side navigation pane, click Instances.

2. In the top navigation bar, select the region where the instance that you want to manage resides. Then, in the upper-left corner, click Create Instance.

3. In the panel that appears, use the default value Subscription for the Billing Method parameter. Then, Click OK.

4. On the buy page that appears, select the instance specifications that you want to purchase based on your business requirements, select Terms of Service, and then click Buy Now.

   For information about the instance editions provided by ApsaraMQ for MQTT and their feature differences, see Instance editions.

5. On the order payment page, follow the on-screen instructions to complete the payment.

Create a topic

1. Log on to the ApsaraMQ for MQTT console. In the left-side navigation pane, click Instances.

2. In the top navigation bar, select the region where the instance that you want to manage resides. On the Instances page, click the instance name to go to the Instance Details page.

3. In the left-side navigation pane, click Topics. In the upper-left corner of the Topics page, click Create Topic.
4. In the Create Topic panel, set the Name and Description parameters for the topic and click OK in the lower-left corner.

Create a group

1. Log on to the ApsaraMQ for MQTT console. In the left-side navigation pane, click Instances.

2. In the top navigation bar, select the region where the instance that you want to manage resides. On the Instances page, click the instance name to go to the Instance Details page.

3. In the left-side navigation pane, click Groups. In the upper-left corner of the Groups page, click Create Group.
4. In the Create Group panel, set the Group ID parameter and click OK.

Step 2: Map parameters in the open source SDK

Add dependencies

<dependency>
            <groupId>commons-codec</groupId>
            <artifactId>commons-codec</artifactId>
            <version>1.10</version>
        </dependency>
        <dependency>
            <groupId>org.eclipse.paho</groupId>
            <artifactId>org.eclipse.paho.client.mqttv3</artifactId>
            <version>1.2.2</version>
        </dependency>
        <dependency>
            <groupId>org.apache.httpcomponents</groupId>
            <artifactId>httpclient</artifactId>
            <version>4.5.2</version>
        </dependency>
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>fastjson</artifactId>
            <version>1.2.48</version>
        </dependency>
        <dependency>
            <groupId>com.aliyun</groupId>
            <artifactId>aliyun-java-sdk-onsmqtt</artifactId>
            <version>1.0.3</version>
        </dependency>
        <dependency>
            <groupId>com.aliyun</groupId>
            <artifactId>aliyun-java-sdk-core</artifactId>
            <version>4.5.0</version>
        </dependency>

Add a signature algorithm

If you use signature authentication to authenticate a client, you must add a signature algorithm to specify a value for the mqttConnectOptions.setPassword parameter.

Tools.macSignature(clientId, secretKey).toCharArray()

For information about the sample code, see Demo projects.

Modify parameter values in the SDK

The following table describes the parameters you must modify based on ApsaraMQ for MQTT parameters in the SDK.

Step 3: Send and receive messages

After you modify the parameter values, you can start the open source client SDK. Then, you can access ApsaraMQ for MQTT to send and receive messages by using the SDK.

References

Shared subscription

If you want to use the shared subscription capability, you can use cloud SDKs provided by ApsaraMQ for MQTT.

You can use cloud SDKs to deploy distributed applications in the cloud. Cloud SDKs support the shared subscription, messaging, message subscription, and client status notification capabilities. Cloud SDK for Java and cloud SDK for Go are available. For more information, see Overview.

Cloud SDKs provided by ApsaraMQ for MQTT allow you to send and receive messages on ApsaraMQ for MQTT brokers instead of the MQTT protocol.