Apache Helix – Near-Realtime Rsync Replicated File System
Minor rant: The trouble with all these lovely Apache projects is their dependency on Java.If these things were written in C, Go or Rust then I'd leap at the opportunity to explore them and maybe use them in production.But Java dependency just brings so much baggage with it.  Its all well and good if you've got a Java pro or two on your team. But if you don't, you usually end up spending hours and days troubleshooting obscure JVM problems or somesuch.