Known bug, Fixed with 4.5.5. Please upgade to this version or later to solve the issue.
Observation
The following warning are seen in HiveMQ logs:
WARN - Serialization of kafka metrics failed: java.lang.IllegalArgumentException: Message size to large. Maximum allowed: 5242880 | Received: 5710237
Consequence
Impact : (Severe, Cosmetic)
(E.g. broker cannot accept any additional connection, as there are not file descriptors for network sockets left. This might also impact the ability to write log files or replicate data.)
Cause
This is a known bug where the size of the Kafka metrics increase beyond the set limit of 5 MB, leading to this error.
Solution
The bug is fixed in 4.5.5. Please upgrade to resolve this issue.