When an older Hadoop version tries to contact a newer Hadoop version across an IPC protocol version bump, the client currently just gets a non-useful error message like "EOFException".
Instead, the IPC server code can speak just enough of prior IPC protocols to send back a "fatal" message indicating the version mismatch.
|Status||Open [ 1 ]||Patch Available [ 10002 ]|
|Status||Patch Available [ 10002 ]||Resolved [ 5 ]|
|Resolution||Fixed [ 1 ]|