Fine tune flow limit of incoming connections in Rabbit MQ

[Sravani Cheruvu]

Hi Team,

Currently we are using 3.12.13 and Erlang 26.2.2

We have a load balanced cluster with two linux nodes , each node is have 16 processors and 64 GB RAM

Here are RMQ settings :

File descriptors is 65535 

socket descriptors 58892

Erlang processors 1048576

Memory High water mark 25 GB

Disk space 100 GB

SSL handshake timeout is 30 seconds

authentication backend ldap timeout is 60 seconds

We are receiving 1000 active connections at once and we are continuously seeing the error handshake timeout in rabbit mq logs.

Message publish rate is 135 /s

we see that CPU utilisation and Memory utilisation for each linux node is below 60%

RMQ Memory utilisation is below water mark which is 10 GB

But still we see Handshake errors most of the time..

Please let us know if there are any fine tune settings to control the flow limit of huge incoming connections without impacting server performance in RabbitMQ.

Thanks,

Lakshmi Sravani K.

[Sravani Cheruvu]

Please note that , all these 10000 connections are coming from a single user to rabbitmq cluster via loadbalancer

---------- Forwarded message ---------
From: Sravani Cheruvu <srava...@gmail.com>
Date: Fri, Oct 17, 2025 at 4:40 PM
Subject: Fine tune flow limit of incoming connections in Rabbit MQ
To: <rabbitm...@googlegroups.com>

Hi Team,

Currently we are using 3.12.13 and Erlang 26.2.2

We have a load balanced cluster with two linux nodes , each node is have 16 processors and 64 GB RAM

Here are RMQ settings :

File descriptors is 65535 

socket descriptors 58892

Erlang processors 1048576

Memory High water mark 25 GB

Disk space 100 GB

SSL handshake timeout is 30 seconds

authentication backend ldap timeout is 60 seconds

We are receiving 10000 active connections at once and we are continuously seeing the error handshake timeout in rabbit mq logs.

[Lucas Weis Polesello]

Hey Sravani,

I think the Rabbit team won't jump into issues regarding versions lower than 4.1.4 (current LTS).

For the community to help out I think we might need more information about the setup?

What do you mean by `load balanced`? Do you mean an AMQP Proxy of connections? Can you share more details?

Also, are you able to reproduce the issue in some script (i.e spamming connections to repro)?