Message Queue for Apache Kafka:Create a MaxCompute sink connector

Precautions

• You can only export data from a data source topic of a Message Queue for Apache Kafka instance to a MaxCompute table within the same region. For more information about the limits on connectors, see Limits.
• If the instance that contains the data source topic is in the China (Hangzhou) or China (Chengdu) region, the connector task is published to EventBridge.
  • At present, EventBridge is free of charge. For more information, see Billing.
  • When you create a connector, EventBridge creates the AliyunServiceRoleForEventBridgeSourceKafka service-linked role for you.
    • If the service-linked role is not available, EventBridge automatically creates one for you to allow EventBridge to access Message Queue for Apache Kafka.
    • If the service-linked role is available, EventBridge does not create a new one.
    For more information about service-linked roles, see Service-linked roles.
  • You cannot view the operational logs of connector tasks that are published to EventBridge. After a connector task is completed, you can view the consumption details of the groups that subscribe to the data source topic to see the status of the connector task. For more information, see View consumption details.

Procedure

To export data from a data source topic of a Message Queue for Apache Kafka instance to a MaxCompute table by using a MaxCompute sink connector, perform the following steps:

1. Grant Message Queue for Apache Kafka the permissions to access MaxCompute.
   • Create a RAM role
   • Add permissions
2. Optional: Create the topics and group that are required by a MaxCompute sink connector.

   If you do not want to manually create the topics and group, skip this step and set the Resource Creation Method parameter to Auto in the next step.

   Important Specific topics that are required by a MaxCompute sink connector must use a local storage engine. If the major version of your Message Queue for Apache Kafka instance is 0.10.2, topics that use a local storage engine cannot be created manually and must be created automatically.
   1. Create the topics that are required by a MaxCompute sink connector
   2. Create the group that is required by a MaxCompute sink connector
3. Create and deploy a MaxCompute sink connector
4. Verify the result.
   1. Send a test message
   2. View data in the MaxCompute table

Create a RAM role

You cannot select Message Queue for Apache Kafka as the trusted service when you create a RAM role. Therefore, select any service that can be the trusted service first. Then, manually modify the trust policy of the RAM role.

1. Log on to the RAM console.
2. In the left-side navigation pane, click RAM Roles.
3. On the RAM Roles page, click Create RAM Role.
4. In the Create Role panel, perform the following operations:
   1. Select Alibaba Cloud Service as the trusted entity and click Next.
   2. Set the Role Type parameter to Normal Service Role. In the RAM Role Name field, enter AliyunKafkaMaxComputeUser1. From the Select Trusted Service drop-down list, select MaxCompute. Then, click OK.
5. On the Roles page, find and click AliyunKafkaMaxComputeUser1.
6. On the AliyunKafkaMaxComputeUser1 page, click the Trust Policy Management tab and then click Edit Trust Policy.
7. In the Edit Trust Policy panel, replace fc in the script with alikafka and click OK.
   

Add permissions

To use a MaxCompute sink connector to export messages to a MaxCompute table, you must grant the following permissions to the RAM role.

For more information about the preceding permissions and how to grant these permissions, see MaxCompute permissions.

To grant the required permissions to AliyunKafkaMaxComputeUser1, perform the following steps:

1. Log on to the MaxCompute client.
2. Run the following command to add the AliyunKafkaMaxComputeUser1 RAM role as a RAM user:

   add user `RAM$<accountid>:role/aliyunkafkamaxcomputeuser1`;

   Note Replace <accountid> with the ID of your Alibaba Cloud account.
3. Grant the RAM user the minimum permissions that are required to access MaxCompute.
   1. Run the following command to grant the RAM user the permissions on the connector_test project:

      grant CreateInstance on project connector_test to user `RAM$<accountid>:role/aliyunkafkamaxcomputeuser1`;

      Note Replace <accountid> with the ID of your Alibaba Cloud account.
   2. Run the following command to grant the RAM user the permissions on the test_kafka table:

      grant Describe, Alter, Update on table test_kafka to user `RAM$<accountid>:role/aliyunkafkamaxcomputeuser1`;

      Note Replace <accountid> with the ID of your Alibaba Cloud account.

Create the topics that are required by a MaxCompute sink connector

In the Message Queue for Apache Kafka console, you can manually create the five topics that a MaxCompute sink connector requires. The five topics are the task offset topic, task configuration topic, task status topic, dead-letter queue topic, and error data topic. The five topics differ in partition count and storage engine. For more information, see Parameters in the Configure Source Service step.

1. Log on to the Message Queue for Apache Kafka console.
2. In the Resource Distribution section of the Overview page, select the region where your instance is deployed.
   Important You must create topics in the region where your application is deployed. When you create a topic, select the region where your Elastic Compute Service (ECS) instance is deployed. A topic cannot be used across regions. For example, if your message producers and consumers run on ECS instances that are deployed in the China (Beijing) region, create topics in the China (Beijing) region.
3. On the Instances page, click the name of the instance that you want to manage.
4. In the left-side navigation pane, click Topics.
5. On the Topics page, click Create Topic.
6. In the Create Topic panel, configure the parameters and click OK.
   

   Parameter	Description	Example
   Name	The name of the topic.	demo
   Description	The description of the topic.	demo test
   Partitions	The number of partitions of the topic.	12
   Storage Engine	The storage engine of the topic. Message Queue for Apache Kafka supports the following storage engines: Cloud Storage: If you specify this value, the system uses Alibaba Cloud disks for the topic and stores data in three replicas in distributed mode. This storage engine provides the following benefits: low latency, high performance, durability, and high reliability. If you set the Instance Edition parameter to Standard (High Write) when you created the instance, you can specify only Cloud Storage as the value of the Storage Engine parameter. Local Storage: If you specify this value, the system uses the in-sync replicas (ISR) algorithm of open source Apache Kafka and stores data in three replicas in distributed mode.	Cloud Storage
   Message Type	The message type of the topic. Normal Message: By default, messages of the same key are stored in the same partition in the order in which the messages are sent. When a broker in the cluster fails, the order of the messages may not be preserved in affected partitions. If you set the Storage Engine parameter to Cloud Storage, this parameter is automatically set to Normal Message. Partitionally Ordered Message: By default, messages of the same key are stored in the same partition in the order in which the messages are sent. When a broker in the cluster breaks down, the messages are stored in the same order in the partitions that are affected by the failed broker. The affected partitions cannot store new messages until the partitions are restored. If you set the Storage Engine parameter to Local Storage, this parameter is automatically set to Partitionally Ordered Message.	Normal Message
   Log Cleanup Policy	The log cleanup policy for the topic. If you set the Storage Engine parameter to Local Storage, configure the Log Cleanup Policy parameter. Message Queue for Apache Kafka provides the following log cleanup policies: Delete: The default log cleanup policy is used. If sufficient storage space is available in the system, messages are retained based on the maximum retention period. After the storage usage exceeds 85%, the system deletes messages in the order in which the messages are stored. The earliest message that is stored is the first message that is deleted. This helps ensure that the performance of the service is not degraded. Compact: The Apache Kafka log compaction policy is used. If the log compaction policy is used and the keys of different messages are the same, the system retains the most recent message that is stored. This policy applies to scenarios in which the system recovers from a failure, or the cache is reloaded after a system restart. For example, when you use Kafka Connect or Confluent Schema Registry, you must store the information about the system status and configurations in a log-compacted topic. Important You can use log-compacted topics only in specific ecosystem components such as Kafka Connect and Confluent Schema Registry. You cannot use the log compaction policy for a topic that is used to send and receive messages in other components. For more information, see Message Queue for Apache Kafka demos.	Compact
   Tag	The tags that you want to attach to the topic.	demo

   After the topic is created, the topic is displayed on the Topics page.

Create the group that is required by a MaxCompute sink connector

In the Message Queue for Apache Kafka console, you can manually create the group that is required by a MaxCompute sink connector. The name of the group must be in the connect-task name format. For more information, see Parameters in the Configure Source Service step.

1. Log on to the Message Queue for Apache Kafka console.
2. In the Resource Distribution section of the Overview page, select the region where your instance is deployed.
3. On the Instances page, click the name of the instance that you want to manage.
4. In the left-side navigation pane, click Groups.
5. On the Groups page, click Create Group.
6. In the Create Group panel, enter the group name in the Group ID field and the group description in the Description field, attach tags to the group, and then click OK.
   After the group is created, you can view the group on the Groups page.

Create and deploy a MaxCompute sink connector

To create and deploy a MaxCompute sink connector that is used to export data from Message Queue for Apache Kafka to MaxCompute, perform the following steps:

1. Log on to the Message Queue for Apache Kafka console.
2. In the Resource Distribution section of the Overview page, select the region where your instance is deployed.
3. On the Instances page, click the name of the instance that you want to manage.
4. In the left-side navigation pane, click Connectors.
5. On the Connectors page, click Create Connector.
6. In the Create Connector wizard, perform the following steps:
   1. In the Configure Basic Information step, set the parameters that are described in the following table and click Next.

      Parameter	Description	Example
      Name	The name of the connector. Take note of the following rules when you specify a connector name: The connector name must be 1 to 48 characters in length. It can contain digits, lowercase letters, and hyphens (-), but cannot start with a hyphen (-). Each connector name must be unique within a Message Queue for Apache Kafka instance. The name of the group that is used by the connector task must be in the connect-task name format. If you have not already created such a group, Message Queue for Apache Kafka automatically creates one for you.	kafka-maxcompute-sink
      Instance	The information about the Message Queue for Apache Kafka instance. By default, the name and ID of the instance are displayed.	demo alikafka_post-cn-st21p8vj****

   2. In the Configure Source Service step, select Message Queue for Apache Kafka as the source service, set the parameters that are described in the following table, and then click Next.
      Note If you have created the topics and consumer group in advance, set the Resource Creation Method parameter to Manual and enter the names of the created resources in the fields below. Otherwise, set the Resource Creation Method parameter to Auto.

      Table 1. Parameters in the Configure Source Service step

      Parameter	Description	Example
      Data Source Topic	The name of the data source topic from which data is to be exported.	maxcompute-test-input
      Consumer Thread Concurrency	The number of concurrent consumer threads used to export data from the data source topic. Default value: 6. Valid values: 1 2 3 6 12	6
      Consumer Offset	The offset where consumption starts. Valid values: Earliest Offset: Consumption starts from the earliest offset. Latest Offset: Consumption starts from the latest offset.	Earliest Offset
      VPC ID	The ID of the virtual private cloud (VPC) where the data export task runs. Click Configure Runtime Environment to display the parameter. The default value is the VPC ID that you specified when you deployed the Message Queue for Apache Kafka instance. You do not need to change the value.	vpc-bp1xpdnd3l***
      vSwitch ID	The ID of the vSwitch where the data export task runs. Click Configure Runtime Environment to display the parameter. The vSwitch must be deployed in the same VPC as the Message Queue for Apache Kafka instance. The default value is the vSwitch ID that you specified when you deployed the Message Queue for Apache Kafka instance.	vsw-bp1d2jgg81***
      Failure Handling Policy	Specifies whether to retain the subscription to a partition where a message send failure occurs. Click Configure Runtime Environment to display the parameter. Valid values: Continue Subscription: retains the subscription to the partition where the error occurred and returned the logs. Stop Subscription: stops the subscription to the partition where the error occurred and returned the logs. Note For more information, see Manage a connector. For more information about how to troubleshoot errors based on error codes, see Error codes.	Continue Subscription
      Resource Creation Method	The method to create the topics and group that are required by the MaxCompute sink connector. Click Configure Runtime Environment to display the parameter. Auto Manual	Auto
      Connector Consumer Group	The group that is used by the data export task of the connector. Click Configure Runtime Environment to display the parameter. The name of the group must be in the connect-task name format.	connect-kafka-maxcompute-sink
      Task Offset Topic	The topic that is used to store consumer offsets. Click Configure Runtime Environment to display the parameter. Topic: We recommend that you start the topic name with connect-offset. Partitions: The number of partitions in the topic must be greater than 1. Storage Engine: The storage engine of the topic must be set to Local Storage. cleanup.policy: The log cleanup policy for the topic must be set to Compact.	connect-offset-kafka-maxcompute-sink
      Task Configuration Topic	The topic that is used to store task configurations. Click Configure Runtime Environment to display the parameter. Topic: We recommend that you start the topic name with connect-config. Partitions: The topic can contain only one partition. Storage Engine: The storage engine of the topic must be set to Local Storage. cleanup.policy: The log cleanup policy for the topic must be set to Compact.	connect-config-kafka-maxcompute-sink
      Task Status Topic	The topic that is used to store the task status. Click Configure Runtime Environment to display the parameter. Topic: We recommend that you start the topic name with connect-status. Partitions: We recommend that you set the number of partitions in the topic to 6. Storage Engine: The storage engine of the topic must be set to Local Storage. cleanup.policy: The log cleanup policy for the topic must be set to Compact.	connect-status-kafka-maxcompute-sink
      Dead-letter Queue Topic	The topic that is used to store the error data of the Kafka Connect framework. Click Configure Runtime Environment to display the parameter. To save topic resources, you can create a topic as both the dead-letter queue topic and the error data topic. Topic: We recommend that you start the topic name with connect-error. Partitions: We recommend that you set the number of partitions in the topic to 6. Storage Engine: The storage engine of the topic can be set to Local Storage or Cloud Storage.	connect-error-kafka-maxcompute-sink
      Error Data Topic	The topic that is used to store the error data of the connector. Click Configure Runtime Environment to display the parameter. To save topic resources, you can create a topic as both the dead-letter queue topic and the error data topic. Topic: We recommend that you start the topic name with connect-error. Partitions: We recommend that you set the number of partitions in the topic to 6. Storage Engine: The storage engine of the topic can be set to Local Storage or Cloud Storage.	connect-error-kafka-maxcompute-sink

   3. In the Configure Destination Service step, select MaxCompute as the destination service, set the parameters that are described in the following table, and then click Create.
      Note If the instance that contains the data source topic is in the China (Hangzhou) or China (Chengdu) region, the Service Authorization dialogue box appears when you select MaxCompute as the destination service. Click OK in the Service Authorization dialogue box, set the parameters described in the following table, and click Create.

      Parameter	Description	Example
      Endpoint	The endpoint of MaxCompute. For more information, see Endpoints. VPC endpoint: We recommend that you use the VPC endpoint because it has lower latency. The VPC endpoint can be used if the Message Queue for Apache Kafka instance and the MaxCompute project are in the same region. Public endpoint: We recommend that you do not use the public endpoint because it has higher latency. The public endpoint can be used if the Message Queue for Apache Kafka instance and the MaxCompute project are in different regions. To use the public endpoint, you must enable Internet access for the connector. For more information, see Enable Internet access for a connector.	http://service.cn-hangzhou.maxcompute.aliyun-inc.com/api
      Workspace	The name of the MaxCompute project to which you want to export data.	connector_test
      Table	The name of the MaxCompute table to which you want to export data.	test_kafka
      Region for Table	The region where the MaxCompute table is created.	China (Hangzhou)
      Alibaba Cloud Account ID	The ID of the Alibaba Cloud account that is used to access MaxCompute.	188***
      RAM Role	The name of the RAM role that is assumed by Message Queue for Apache Kafka. For more information, see Create a RAM role.	AliyunKafkaMaxComputeUser1
      Mode	The mode in which messages are exported to the MaxCompute sink connector. Default value: DEFAULT. Valid values: KEY: Only the keys of messages are retained and written into the Key column of the MaxCompute table. VALUE: Only the values of messages are retained and written into the Value column of the MaxCompute table. DEFAULT: Both keys and values of messages are retained. Keys are written into the Key column and values are written into the Value column of the MaxCompute table. Important In the DEFAULT mode, the CSV format is not supported. You can select only the TEXT and BINARY formats.	DEFAULT
      Format	The format in which messages are exported to the MaxCompute sink connector. Default value: TEXT. Valid values: TEXT: strings BINARY: byte arrays CSV: strings separated with commas (,) Important If you set the parameter to CSV, the DEFAULT mode is not supported. Only the KEY and VALUE modes are supported. KEY mode: Only the keys of messages are retained. Keys are separated with commas (,) and then written into the MaxCompute table in the order of indexes. VALUE mode: Only the values of messages are retained. Values are separated with commas (,) and then written into the MaxCompute table in the order of indexes.	TEXT
      Partition	The frequency at which partitions are created. Default value: HOUR. Valid values: DAY: writes data into a new partition every day. HOUR: writes data into a new partition every hour. MINUTE: writes data into a new partition every minute.	HOUR
      Time Zone	The time zone of the Message Queue for Apache Kafka producer client that sends messages to the data source topic. Default value: GMT 08:00.	GMT 08:00

      After the connector is created, you can view it on the Connectors page.
7. Go to the Connectors page, find the connector that you created, and then click Deploy in the Actions column.

Send a test message

After you deploy the MaxCompute sink connector, you can send a message to the data source topic in Message Queue for Apache Kafka to test whether the message can be exported to MaxCompute.

1. On the Connectors page, find the connector that you want to use and click Test in the Actions column.
2. In the Send Message panel, configure the required parameters to send a test message.
   • Set the Method of Sending parameter to Console.
     1. In the Message Key field, enter the key of the message. For example, you can enter demo as the key of the message.
     2. In the Message Content field, enter the content of the message. For example, you can enter {"key": "test"} as the content of the message.
     3. Configure the Send to Specified Partition parameter to specify whether to send the message to a specific partition.
        • If you want to send the message to a specific partition, click Yes and enter the partition ID in the Partition ID field. For example, you can enter 0 as the partition ID. For information about how to query partition IDs, see View partition status.
        • If you do not want to send the message to a specific partition, click No.
   • Set the Method of Sending parameter to Docker and run the docker commands that are provided in the Run the Docker container to produce a sample message section to send a test message.
   • Set the Method of Sending parameter to SDK and click the link to the topic that describes how to obtain and use the SDK that you want to use. Then, use the SDK to send and consume a test message. Message Queue for Apache Kafka provides topics that describe how to use SDKs for different programming languages based on different connection types.

View data in the MaxCompute table

After you send a message to the data source topic in Message Queue for Apache Kafka, you can log on to the MaxCompute client to check whether the message is received.

To view the test_kafka table, perform the following steps:

1. Log on to the MaxCompute client.
2. Run the following command to view the partitions of the table:

   show partitions test_kafka;

   In this example, the following result is returned:

   pt=11-17-2020 15
   
   OK

3. Run the following command to view the data stored in the partitions:

   select * from test_kafka where pt ="11-17-2020 14";

   In this example, the following result is returned:

   +----------------------+------------+------------+-----+-------+---------------+
   | topic                | partition  | offset     | key | value | pt            |
   +----------------------+------------+------------+-----+-------+---------------+
   | maxcompute-test-input| 0          | 0          | 1   | 1     | 11-17-2020 14 |
   +----------------------+------------+------------+-----+-------+---------------+