Does not preserve Compatibility with index queries against 1.0 nodes. Command usage of RangeSliceCommand that used to work on version 1.0 won't work on 1.1 nodes (no data damange though). This will cause problem especially during live upgrade.
no, no warning or exception. Fail silently.
Yes. Need to perform a rolling update from 1.0-> 1.1. Rolling update means update without interruption.
all clients. RangeSlice command is a frequently used command. A client should except to hit the failed code path easily.
no, no dataloss. Can be recovered
perform rolling update from cassandra 1.0 => 1.1
Setup standard 1.0 node
Start rolling upgrade from version 1.0 to 1.1. Then send out range slice command.
1. start rolling upgrade
2. sending out rangeslice command (feature start)
yes. Logs tell us that the system is rollign forward
rangeslice command errors out
Since we are in the middle of a rolling upgrade from 1.0 to 1.1. It is very l likely the problem broken by the rolling upgrade. Indeed, if we look at the code, 1.1 does not preserve compatibility with index queries against 1.0 nodes.
Did not preserve backwards compatibility with earlier version.
The fix made a separate code path for to make the nodes compatible between two version. THe developer added a function to convert IndexScanCommand for backwards compatibility