@bdelpizzo Can you see any error in kafka logs/mirror maker logs? It might be possible that the mirror maker is not able to process messages, because of size of message. If the size of any message is high than configured/default value then it might stuck in queue.   Check for message.max.bytes property ... View more

@srowen Is 12 executors really necessary?  Surely you just need a total of 12 cores (so you could have 1 executor with 12 cores).   Is this what you mean by "Also, 1 core per executor is generally very low."?   What happens when you have more cores than kafka partitions? will it generall run faster? ... View more