> But if you could rebuild streaming from the ground up for the cloud, you could achieve something a lot better than fewer disks – zero disks. The difference between some disks and zero disks is night and day. Zero disks, with everything running directly through object storage with no intermediary disks, would be better.<p>That's still a trade-off. Object storage, simply by the overhead of HTTP + SSL, has higher latency than EFS, which has higher latency than EBS, which has higher latency than local SSD. So in the end your service (no matter if it's Kafka or anything else) has _higher_ latency if you also want consistency (aka resilience against "everything goes dark in an instant") as all writes on all machines in the pool have to be committed to storage.<p>The only way a "zero disk" <i>anything</i> makes sense is if you have enough machines in enough diverse locations with enough RAM to cover the entire workload and to pray there's never any event taking the entire cloud provider offline.