Increasing the message size limit on AMQP inputs

1. Describe your incident:
I am trying to receive large messages using AMQP plaintext raw inputs.

I get the following in graylog-server logs:

2025-01-06T10:25:36.244Z ERROR [ForgivingExceptionHandler] An unexpected connection driver error occurred
java.lang.IllegalStateException: Message body is too large (68265620), maximum configured size is 67108864. See ConnectionFactory#setMaxInboundMessageBodySize if you need to increase the limit.
	at com.rabbitmq.client.impl.CommandAssembler.consumeHeaderFrame(CommandAssembler.java:109) ~[graylog.jar:?]
	at com.rabbitmq.client.impl.CommandAssembler.handleFrame(CommandAssembler.java:172) ~[graylog.jar:?]
	at com.rabbitmq.client.impl.AMQCommand.handleFrame(AMQCommand.java:108) ~[graylog.jar:?]
	at com.rabbitmq.client.impl.AMQChannel.handleFrame(AMQChannel.java:123) ~[graylog.jar:?]
	at com.rabbitmq.client.impl.AMQConnection.readFrame(AMQConnection.java:761) [graylog.jar:?]
	at com.rabbitmq.client.impl.AMQConnection.access$400(AMQConnection.java:48) [graylog.jar:?]
	at com.rabbitmq.client.impl.AMQConnection$MainLoop.run(AMQConnection.java:688) [graylog.jar:?]
	at java.base/java.lang.Thread.run(Unknown Source) [?:?]

2. Describe your environment:

  • OS Information:
    Ubuntu 22.04

  • Package Version:
    6.1.4

  • Service logs, configurations, and environment variables:

3. What steps have you already taken to try and solve the problem?
I’ve tried googling how to set these options when using Graylog, with no luck.

As I understand it, messages fail before entering the graylog flow, so putting them in a DLQ is not possible - hence all messages are queueing up.

4. How can the community help?
Any ideas on how to increase this limit are very welcome.

Dit you try editing the input size thru Graylog in the input configuration?

That option is not available for input type “Raw/Plaintext AMQP”, only for “Raw/Plaintext TCP” or “Raw/Plaintext UDP”

You could try overriding the default as described here:

and if it works put the working values in /etc/sysctl.conf.

If you are in a fast network environment it is possible to set some
values higher.