View a markdown version of this page

Resource Limit Configuration - Amazon MQ
Resource names and configuration keysHow to override resource limitsInstance specific section support in configurationResource limit override errors

Resource Limit Configuration

Amazon MQ for RabbitMQ supports configuring broker resource limits from RabbitMQ 4 onwards. When you create a broker, Amazon MQ automatically applies default values to these resource limits. These defaults act as guardrails to protect your broker availability while accommodating common customer usage patterns. You can customize your broker behavior by changing the limit configuration values to better match your specific workload requirements. For more details about default and maximum allowed values, see Amazon MQ for RabbitMQ sizing guidelines.

Resource names and configuration keys

Resource Name Configuration Key
Connection connection_max
Channel channel_max_per_node
Queue cluster_queue_limit
Vhost vhost_max
Shovel runtime_parameters.limits.shovel
Exchange cluster_exchange_limit
Consumer per channel consumer_max_per_channel
Maximum message size max_message_size

How to override resource limits

You can override resource limits using the Amazon MQ API and Amazon MQ console.

The following example shows how to override the queue count default limit using the AWS CLI:


aws mq update-configuration --configuration-id <config-id> --data "$(echo "cluster_queue_limit=500" | base64 --wrap=0)"

A successful invocation creates a configuration revision. You must associate the configuration to your RabbitMQ broker and reboot the broker to apply the override. For more details see RabbitMQ Broker Configurations

Instance specific section support in configuration

With RabbitMQ 4, Amazon MQ supports sections in configuration data. Sections let you define instance-specific resource limits within a single configuration. Each section corresponds to a specific instance type and deployment mode combination. When you associate the configuration with a broker, Amazon MQ automatically applies the matching section for the broker's instance type and deployment mode.

Important

Section support is only available on RabbitMQ 4. If you attempt to apply a configuration that contains sections to a RabbitMQ 3 broker, the API returns a BadRequestException.

Section syntax

Sections are delimited by double curly braces with the following format:


{{<host-instance-family>.<size>.<mode>}}

The mode value indicates the deployment mode:

  • 1 – Single-instance broker

  • 3 – Cluster broker

Any other mode value is invalid and the API returns an error.

The following example shows configuration data with sections for two different instance types:


connection_max = 1000

{{m7g.large.3}}
connection_max = 2000
{{m7g.large.3}}

{{m7g.xlarge.3}}
connection_max = 4000
{{m7g.xlarge.3}}

Allowed configuration keys in sections

Only the following resource limit configuration keys are supported inside a section. Adding any other configuration key inside a section results in an API error.

  • max_message_size

  • channel_max_per_node

  • connection_max

  • cluster_queue_limit

  • vhost_max

  • consumer_max_per_channel

  • runtime_parameters.limits.shovel

  • cluster_exchange_limit

Section precedence rules

When a configuration key appears in both the generic (top-level) section and an instance-specific section, the value that appears later in the configuration data takes precedence. For example, applying the following configuration to an m7g.large cluster broker sets connection_max to 2000:


connection_max = 1000

{{m7g.large.3}}
connection_max = 2000
{{m7g.large.3}}

Reversing the order sets connection_max to 1000, because the generic value comes last:


{{m7g.large.3}}
connection_max = 2000
{{m7g.large.3}}

connection_max = 1000
Note

If the configuration data does not define values for a particular instance type, Amazon MQ applies the default values.

Examples

The following examples show how to create a configuration with sections and associate it with a broker using the AWS CLI.

To update a configuration with sections

Run the following command to update a configuration with instance-specific resource limits for multiple instance types:


aws mq update-configuration \
    --configuration-id <config-id> \
    --data "$(echo -e "connection_max = 1000\nchannel_max_per_node = 64\n\n{{m7g.large.3}}\nconnection_max = 2000\nchannel_max_per_node = 128\n{{m7g.large.3}}\n\n{{m7g.xlarge.3}}\nconnection_max = 4000\nchannel_max_per_node = 256\n{{m7g.xlarge.3}}" | base64 --wrap=0)"

This configuration defines the following values:

  • Generic defaults: connection_max = 1000 and channel_max_per_node = 64

  • m7g.large cluster brokers: connection_max = 2000 and channel_max_per_node = 128

  • m7g.xlarge cluster brokers: connection_max = 4000 and channel_max_per_node = 256

To associate the configuration with a broker

After you update the configuration, associate it with your broker and reboot the broker to apply the changes. Run the following command:


aws mq update-broker \
    --broker-id <broker-id> \
    --configuration id=<config-id>,revision=<revision-number>

Resource limit override errors

Associating or creating a broker with configuration values outside the supported range results in an error response similar to the following:


Configuration Revision N for configuration:cluster_queue_limit has limit: of value: 100000000 larger than maximum allowed limit:5000

For default values and maximum supported ranges by instance type and deployment mode, see Default resource limits and Amazon MQ for RabbitMQ maximum resource limit.