+1 to Bowen Song's feedback for the most part. We have processes that parse output from these nodetool commands:
- info - netstats - status - version My opinion is that for anyone running a reasonably sized fleet of Cassandra will have different flavors of automation - some things running on the nodes themselves where nodetool is very handy and some things running outside the cluster where virtual tables accessed via cql are preferred. I propose a rule that within a given major version, additional lines of output are acceptable changes, but changes to the format of existing lines of output are forbidden. I would be inclined to accept JSON or YAML output from nodetool for Ruby/Python/etc scripts, but for bash, the human-readable output is more work-able. On Mon, Jul 10, 2023 at 4:35 AM Miklosovic, Stefan < stefan.mikloso...@netapp.com> wrote: > Hi Cassandra users, > > I am a Cassandra developer and we in Cassandra project would love to know > if there are users out there for whom the output of the tooling, like, > nodetool, is important when it comes to parsing it. > > We are elaborating on the consequences when nodetool's output for various > commands is changed - we are not completely sure if users are parsing this > output in some manner in their custom scripts so us changing the output > would break their scripts which are parsing it. > > Additionally, how big of a problem the output change would be if it was > happening only between major Cassandra versions? E.g. 4.0 -> 5.0 or 5.0 -> > 6.0 only. In other words, there would be a guarantee that no breaking > changes in minor versions would ever occur. Only in majors. > > Is somebody out there who is relying on the output of some particular > nodetool commands (or any command in tools/bin) in production? How often do > you rely on the parsing of nodetool's output and how much work it would be > for you to rework some minor changes? For example, when the tool output > prints "someStatistic: 10" and we would rework it to "Some Statistic: 10". > > Would you be OK if the output changed but you would have a way how to get > e.g. JSON or YAML output instead by some flag on nodetool command so it > would be irrelevant what the default output would be? > > It would be appreciated a lot if you gave us more feedback on this. I > understand that not all questions are relatable to everyone. > > Even you are not relying on the output of the tooling in some custom > scripts where you parse it, please tell us so. We are progressively trying > to provide CQL way how to query the internal state of Cassandra, via > virtual tables, for example. > > Regards > > Stefan Miklosovic -- Andrew Weaver
