Hello HDFS Development Community, I hope you’re doing well. I have an HDFS HA cluster where the NameNode and DataNodes are currently running on version **2.10.2**, but I need to upgrade our HDFS client to **3.3.6** for compatibility with some newer tooling.
**My main question**: Is there guaranteed **wire-protocol compatibility** between a **2.10.2** HDFS server and a **3.3.6** client? We do not use any authentication system (e.g., Kerberos), and our workload is limited to reading and writing CSV and Parquet files. I have already reviewed the official Compatibility Guide and some JIRA issues, but I’d appreciate confirmation from the HDFS maintainers on whether any known protobuf or RPC changes in 3.x would break wire compatibility with a 2.10.2 cluster. Thank you for your time and guidance! Best regards, Alireza Asgarian
