QOS 0 Memory Exceeded

Hi Team
I have a doubts in HiveMQ QOS-0 memory, Yesterday I received notification in HiveMQ there was Dropped Message: QoS-0 memory Exceeded.
Also, I checked the logs in HiveMQ, its exceed the memory limit. Below attached the screenshots for your reference.

There is any limit for QOS-0 memory? or How to find the QoS-0 memory limit?
Also referred Documentation and previous community questions but its not helpful for me.
Can you please help me for resolve the issue?



Can you please give some insights into this?

Hi Harry,

That error generally boils down to subscribers consuming from topics slower than publishers publishing to them, creating a bottleneck. This is covered in a few places, but some documentation and discussions are below:



It may seem like a good idea at first to try to increase memory allowance when encountering this error, but in the end it is often a trap - increasing the memory used by the in memory queue without addressing the client consumption problem may only end up giving a higher ceiling before the problem reoccurs.

Seth - HiveMQ Support

Hi @Seth.HiveMQ @hivemq-support

Thank you for your response Seth,

I referred to these topics that you have mentioned it. I have doubts about this,
We using VM and its Capacity is:
cpu: 8
ephemeral-storage: 129886128Ki
and CPU occupied 51% and storage occupied 29% only. Is there any possible ways to drop the messages?
The Consumers are slowly consuming the messages so that the messages are dropped, right?

From these 2 questions which one is applicable to my issue?

Is there any way to increase the QoS 0 memory limit in HiveMQ?
How to increase the memory allowance can you please give some insights?

Also, I analyzed HiveMQ logs, and while analyzing the logs I saw there are multiple dropped messages are dropped in different topics. Is there any idea?

Regards & Thanks