Multicast Socket Buffer in AWS


I see the following in my logs:

2020-05-08 13:46:37,457 WARN - JGRP000015: the send buffer of socket MulticastSocket was set to 5.00MB, but the OS only allocated 212.99KB. This might lead to performance problems. Please set your max send buffer in the OS correctly (e.g. net.core.wmem_max on Linux)

I’m running HiveMQ in AWS EKS and would like to know if I should tune this parameter as I’ve thought multicast was not supported in AWS.


Hi @lsattler,

This message refers to the TCP read/write buffer that is used for inter cluster communication. This multicast can be used on EKS. You cannot configure this value on EKS, however.
As long as the buffer size is bigger than 200kb this warning can be ignored.

PS: Which HiveMQ version are you using?

Best regards,