Using Lambda with Amazon MQ - Amazon Lambda
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Using Lambda with Amazon MQ


If you want to send data to a target other than a Lambda function or enrich the data before sending it, see Amazon EventBridge Pipes.

Amazon MQ is a managed message broker service for Apache ActiveMQ and RabbitMQ. A message broker enables software applications and components to communicate using various programming languages, operating systems, and formal messaging protocols through either topic or queue event destinations.

Amazon MQ can also manage Amazon Elastic Compute Cloud (Amazon EC2) instances on your behalf by installing ActiveMQ or RabbitMQ brokers and by providing different network topologies and other infrastructure needs.

You can use a Lambda function to process records from your Amazon MQ message broker. Lambda invokes your function through an event source mapping, a Lambda resource that reads messages from your broker and invokes the function synchronously.


Lambda event source mappings process each event at least once, and duplicate processing of records can occur. To avoid potential issues related to duplicate events, we strongly recommend that you make your function code idempotent. To learn more, see How do I make my Lambda function idempotent in the Amazon Knowledge Center.

The Amazon MQ event source mapping has the following configuration restrictions:

  • Concurrency – Lambda functions that use an Amazon MQ event source mapping have a default maximum concurrency setting. For ActiveMQ, the Lambda service limits the number of concurrent execution environments to five. For RabbitMQ, the number of concurrent execution environments is limited to 1. Even if you change your function's reserved or provisioned concurrency settings, the Lambda service won't make more execution environments available. To request an increase in the default maximum concurrency, contact Amazon Web Services Support.

  • Cross account – Lambda does not support cross-account processing. You cannot use Lambda to process records from an Amazon MQ message broker that is in a different Amazon Web Services account.

  • Authentication – For ActiveMQ, only the ActiveMQ SimpleAuthenticationPlugin is supported. For RabbitMQ, only the PLAIN authentication mechanism is supported. Users must use Amazon Secrets Manager to manage their credentials. For more information about ActiveMQ authentication, see Integrating ActiveMQ brokers with LDAP in the Amazon MQ Developer Guide.

  • Connection quota – Brokers have a maximum number of allowed connections per wire-level protocol. This quota is based on the broker instance type. For more information, see the Brokers section of Quotas in Amazon MQ in the Amazon MQ Developer Guide.

  • Connectivity – You can create brokers in a public or private virtual private cloud (VPC). For private VPCs, your Lambda function needs access to the VPC to receive messages. For more information, see Network configuration later in this topic.

  • Event destinations – Only queue destinations are supported. However, you can use a virtual topic, which behaves as a topic internally while interacting with Lambda as a queue. For more information, see Virtual Destinations on the Apache ActiveMQ website, and Virtual Hosts on the RabbitMQ website.

  • Network topology – For ActiveMQ, only one single-instance or standby broker is supported per event source mapping. For RabbitMQ, only one single-instance broker or cluster deployment is supported per event source mapping. Single-instance brokers require a failover endpoint. For more information about these broker deployment modes, see Active MQ Broker Architecture and Rabbit MQ Broker Architecturein the Amazon MQ Developer Guide.

  • Protocols – Supported protocols depend on the type of Amazon MQ integration.

    • For ActiveMQ integrations, Lambda consumes messages using the OpenWire/Java Message Service (JMS) protocol. No other protocols are supported for consuming messages. Within the JMS protocol, only TextMessage and BytesMessage are supported. Lambda also supports JMS custom properties. For more information about the OpenWire protocol, see OpenWire on the Apache ActiveMQ website.

    • For RabbitMQ integrations, Lambda consumes messages using the AMQP 0-9-1 protocol. No other protocols are supported for consuming messages. For more information about RabbitMQ's implementation of the AMQP 0-9-1 protocol, see AMQP 0-9-1 Complete Reference Guide on the RabbitMQ website.

Lambda automatically supports the latest versions of ActiveMQ and RabbitMQ that Amazon MQ supports. For the latest supported versions, see Amazon MQ release notes in the Amazon MQ Developer Guide.


By default, Amazon MQ has a weekly maintenance window for brokers. During that window of time, brokers are unavailable. For brokers without standby, Lambda cannot process any messages during that window.

Lambda consumer group

To interact with Amazon MQ, Lambda creates a consumer group which can read from your Amazon MQ brokers. The consumer group is created with the same ID as the event source mapping UUID.

For Amazon MQ event sources, Lambda batches records together and sends them to your function in a single payload. To control behavior, you can configure the batching window and batch size. Lambda pulls messages until it processes the payload size maximum of 6 MB, the batching window expires, or the number of records reaches the full batch size. For more information, see Batching behavior.

The consumer group retrieves the messages as a BLOB of bytes, base64-encodes them into a single JSON payload, and then invokes your function. If your function returns an error for any of the messages in a batch, Lambda retries the whole batch of messages until processing succeeds or the messages expire.


While Lambda functions typically have a maximum timeout limit of 15 minutes, event source mappings for Amazon MSK, self-managed Apache Kafka, Amazon DocumentDB, and Amazon MQ for ActiveMQ and RabbitMQ only support functions with maximum timeout limits of 14 minutes. This constraint ensures that the event source mapping can properly handle function errors and retries.

You can monitor a given function's concurrency usage using the ConcurrentExecutions metric in Amazon CloudWatch. For more information about concurrency, see Configuring reserved concurrency for a function.

Example Amazon MQ record events
{ "eventSource": "aws:mq", "eventSourceArn": "arn:aws:mq:us-west-2:111122223333:broker:test:b-9bcfa592-423a-4942-879d-eb284b418fc8", "messages": [ { "messageID": "", "messageType": "jms/text-message", "deliveryMode": 1, "replyTo": null, "type": null, "expiration": "60000", "priority": 1, "correlationId": "myJMSCoID", "redelivered": false, "destination": { "physicalName": "testQueue" }, "data":"QUJDOkFBQUE=", "timestamp": 1598827811958, "brokerInTime": 1598827811958, "brokerOutTime": 1598827811959, "properties": { "index": "1", "doAlarm": "false", "myCustomProperty": "value" } }, { "messageID": "", "messageType": "jms/bytes-message", "deliveryMode": 1, "replyTo": null, "type": null, "expiration": "60000", "priority": 2, "correlationId": "myJMSCoID1", "redelivered": false, "destination": { "physicalName": "testQueue" }, "data":"LQaGQ82S48k=", "timestamp": 1598827811958, "brokerInTime": 1598827811958, "brokerOutTime": 1598827811959, "properties": { "index": "1", "doAlarm": "false", "myCustomProperty": "value" } } ] }
{ "eventSource": "aws:rmq", "eventSourceArn": "arn:aws-cn:mq:us-west-2:111122223333:broker:pizzaBroker:b-9bcfa592-423a-4942-879d-eb284b418fc8", "rmqMessagesByQueue": { "pizzaQueue::/": [ { "basicProperties": { "contentType": "text/plain", "contentEncoding": null, "headers": { "header1": { "bytes": [ 118, 97, 108, 117, 101, 49 ] }, "header2": { "bytes": [ 118, 97, 108, 117, 101, 50 ] }, "numberInHeader": 10 }, "deliveryMode": 1, "priority": 34, "correlationId": null, "replyTo": null, "expiration": "60000", "messageId": null, "timestamp": "Jan 1, 1970, 12:33:41 AM", "type": null, "userId": "AIDACKCEVSQ6C2EXAMPLE", "appId": null, "clusterId": null, "bodySize": 80 }, "redelivered": false, "data": "eyJ0aW1lb3V0IjowLCJkYXRhIjoiQ1pybWYwR3c4T3Y0YnFMUXhENEUifQ==" } ] } }

In the RabbitMQ example, pizzaQueue is the name of the RabbitMQ queue, and / is the name of the virtual host. When receiving messages, the event source lists messages under pizzaQueue::/.

Execution role permissions

To read records from an Amazon MQ broker, your Lambda function needs the following permissions added to its execution role:


When using an encrypted customer managed key, add the kms:Decrypt permission as well.

Network configuration

To give Lambda full access to your broker through your event source mapping, either your broker must use a public endpoint (public IP address), or you must provide access to the Amazon VPC you created the broker in.

By default, when you create an Amazon MQ broker, the PubliclyAccessible flag is set to false. For your broker to receive a public IP address, you must set the PubliclyAccessible flag to true.

Best practice for using Amazon MQ with Lambda is to use Amazon PrivateLink VPC endpoints and to give your Lambda function access to your broker's VPC. Deploy an endpoint for Lambda, and, for ActiveMQ only, an endpoint for Amazon Security Token Service (Amazon STS). If your broker uses authentication, also deploy an endpoint for Amazon Secrets Manager. To learn more, see Working with VPC endpoints.

Alternatively, configure a NAT gateway on each public subnet in the VPC containing your Amazon MQ broker. For more information, see Enable internet access for VPC-connected Lambda functions.

When you create an event source mapping for an Amazon MQ broker, Lambda checks whether Elastic Network Interfaces (ENIs) are already present for the subnets and security groups of your broker’s VPC. If Lambda finds existing ENIs, it attempts to re-use them. Otherwise, Lambda creates new ENIs to connect to the event source and invoke your function.


Lambda functions always run inside VPCs owned by the Lambda service. These VPCs are maintained automatically by the service and are not visible to customers. You can also connect your function to an Amazon VPC. In either case, your function’s VPC configuration doesn’t affect the event source mapping. Only the configuration of the event source’s VPC determines how Lambda connects to your event source.

VPC security group rules

Configure the security groups for the Amazon VPC containing your cluster with the following rules (at minimum):

  • Inbound rules – Allow all traffic on the broker port for the security group specified for your event source from within its own security group. ActiveMQ uses port 61617 by default and RabbitMQ uses port 5671 by default.

  • Outbound rules – Allow all traffic on port 443 for all destinations. Allow all traffic on the broker port for within its own security group. ActiveMQ uses port 61617 by default and RabbitMQ uses port 5671 by default.

  • If you use VPC endpoints instead of a NAT gateway, the security groups associated with the VPC endpoints must allow all inbound traffic on port 443 from the event source's security groups.

Working with VPC endpoints

When you use VPC endpoints, API calls to invoke your function are routed through these endpoints using the ENIs. The Lambda service principal needs to call lambda:InvokeFunction on any functions that use those ENIs. Additionally, for ActiveMQ, the Lambda service principal needs to call sts:AssumeRole on roles that use the ENIs.

By default, VPC endpoints have IAM policies which are open. Best practice is to restrict these policies to only allow specific principals to perform the needed actions using that endpoint. To ensure that your event source mapping is able to invoke your Lambda function, the VPC endpoint policy must allow the Lambda service principle to call lambda:InvokeFunction and, for ActiveMQ, sts:AssumeRole. Restricting your VPC endpoint policies to only allow API calls originating within your organization prevents the event source mapping from functioning properly.

The following example VPC endpoint policies show how to grant the required access for Amazon STS and Lambda endpoints.

Example VPC endpoint policy - Amazon STS endpoint (ActiveMQ only)
{ "Statement": [ { "Action": "sts:AssumeRole", "Effect": "Allow", "Principal": { "Service": [ "" ] }, "Resource": "*" } ] }
Example VPC endpoint policy - Lambda endpoint
{ "Statement": [ { "Action": "lambda:InvokeFunction", "Effect": "Allow", "Principal": { "Service": [ "" ] }, "Resource": "*" } ] }

If your Amazon MQ broker uses authentication, you can also restrict the VPC endpoint policy for the Secrets Manager endpoint. To call the Secrets Manager API, Lambda uses your function role, not the Lambda service principal. The following example shows a Secrets Manager endpoint policy.

Example VPC endpoint policy - Secrets Manager endpoint
{ "Statement": [ { "Action": "secretsmanager:GetSecretValue", "Effect": "Allow", "Principal": { "AWS": [ "customer_function_execution_role_arn" ] }, "Resource": "customer_secret_arn" } ] }

Add permissions and create the event source mapping

Create an event source mapping to tell Lambda to send records from an Amazon MQ broker to a Lambda function. You can create multiple event source mappings to process the same data with multiple functions, or to process items from multiple sources with a single function.

To configure your function to read from Amazon MQ, add the required permissions and create an MQ trigger in the Lambda console.

To add permissions and create a trigger
  1. Open the Functions page of the Lambda console.

  2. Choose the name of a function.

  3. Choose the Configuration tab, and then choose Permissions.

  4. Under Role name, choose the link to your execution role. This link opens the role in the IAM console.

    Link to execution role
  5. Choose Add permissions, and then choose Create inline policy.

    Create inline policy in IAM console
  6. In the Policy editor, choose JSON. Enter the following policy. Your function needs these permissions to read from an Amazon MQ broker.

    { "Version": "2012-10-17", "Statement": [ { "Effect": "Allow", "Action": [ "mq:DescribeBroker", "secretsmanager:GetSecretValue", "ec2:CreateNetworkInterface", "ec2:DeleteNetworkInterface", "ec2:DescribeNetworkInterfaces", "ec2:DescribeSecurityGroups", "ec2:DescribeSubnets", "ec2:DescribeVpcs", "logs:CreateLogGroup", "logs:CreateLogStream", "logs:PutLogEvents" ], "Resource": "*" } ] }

    When using an encrypted customer managed key, you must also add the kms:Decrypt permission.

  7. Choose Next. Enter a policy name and then choose Create policy.

  8. Go back to your function in the Lambda console. Under Function overview, choose Add trigger.

    Function overview section of the Lambda console
  9. Choose the MQ trigger type.

  10. Configure the required options, and then choose Add.

Lambda supports the following options for Amazon MQ event sources:

  • MQ broker – Select an Amazon MQ broker.

  • Batch size – Set the maximum number of messages to retrieve in a single batch.

  • Queue name – Enter the Amazon MQ queue to consume.

  • Source access configuration – Enter virtual host information and the Secrets Manager secret that stores your broker credentials.

  • Enable trigger – Disable the trigger to stop processing records.

To enable or disable the trigger (or delete it), choose the MQ trigger in the designer. To reconfigure the trigger, use the event source mapping API operations.

Update the event source mapping

Use the update-event-source-mapping command to update an event source mapping. The following example command updates an event source mapping to have a batch size of 2.

aws lambda update-event-source-mapping \ --uuid 91eaeb7e-c976-1234-9451-8709db01f137 \ --batch-size 2

You should see the following output:

{ "UUID": "91eaeb7e-c976-1234-9451-8709db01f137", "BatchSize": 2, "EventSourceArn": "arn:aws-cn:mq:us-east-1:123456789012:broker:ExampleMQBroker:b-b4d492ef-bdc3-45e3-a781-cd1a3102ecca", "FunctionArn": "arn:aws-cn:lambda:us-east-1:123456789012:function:MQ-Example-Function", "LastModified": 1601928393.531, "LastProcessingResult": "No records processed", "State": "Updating", "StateTransitionReason": "USER_INITIATED" }

Lambda updates these settings asynchronously. The output will not reflect changes until this process completes. To view the current status of your resource, use the get-event-source-mapping command.

aws lambda get-event-source-mapping \ --uuid 91eaeb7e-c976-4939-9451-8709db01f137

You should see the following output:

{ "UUID": "91eaeb7e-c976-4939-9451-8709db01f137", "BatchSize": 2, "EventSourceArn": "arn:aws-cn:mq:us-east-1:123456789012:broker:ExampleMQBroker:b-b4d492ef-bdc3-45e3-a781-cd1a3102ecca", "FunctionArn": "arn:aws-cn:lambda:us-east-1:123456789012:function:MQ-Example-Function", "LastModified": 1601928393.531, "LastProcessingResult": "No records processed", "State": "Enabled", "StateTransitionReason": "USER_INITIATED" }

Event source mapping errors

When a Lambda function encounters an unrecoverable error, your Amazon MQ consumer stops processing records. Any other consumers can continue processing, provided that they do not encounter the same error. To determine the potential cause of a stopped consumer, check the StateTransitionReason field in the return details of your EventSourceMapping for one of the following codes:


The event source mapping configuration is not valid.


Lambda failed to authenticate the event source.


Lambda does not have the required permissions to access the event source.


The function's configuration is not valid.

Records also go unprocessed if Lambda drops them due to their size. The size limit for Lambda records is 6 MB. To redeliver messages upon function error, you can use a dead-letter queue (DLQ). For more information, see Message Redelivery and DLQ Handling on the Apache ActiveMQ website and Reliability Guide on the RabbitMQ website.


Lambda does not support custom redelivery policies. Instead, Lambda uses a policy with the default values from the Redelivery Policy page on the Apache ActiveMQ website, with maximumRedeliveries set to 6.

Amazon MQ and RabbitMQ configuration parameters

All Lambda event source types share the same CreateEventSourceMapping and UpdateEventSourceMapping API operations. However, only some of the parameters apply to Amazon MQ and RabbitMQ.

Event source parameters that apply to Amazon MQ and RabbitMQ
Parameter Required Default Notes




Maximum: 10,000








Lambda event filtering



500 ms

Batching behavior



The name of the Amazon MQ broker destination queue to consume.



For ActiveMQ, BASIC_AUTH credentials. For RabbitMQ, can contain both BASIC_AUTH credentials and VIRTUAL_HOST information.