@lvferdi are you using SSL? does kafka server to ssl termination? I have a feeling the issue is the ELB and if you're trying to pass through to your back end, you need to make sure its not terminating ssl for osquery and then passing through in cleartext. I'm not familiar with Kafka itself, but those logs are typical of improperly terminated connection, which would indicate that osquery is actually making the connection to the ELB, but the elb is not passing it through