Hi Laurent, That's right; this was mentioned in the design document.
I am piggybacking on previous changes that break the "newer clients talking to older servers" compatibility. For example, as I understand, some resolved sub-tasks of DRILL-4714 [1] *implicitly* break this compatibility; say the "newer" API that was introduced is used by an application which is talking to an older server. The older server drops the connection, unable to handle the message. In DRILL-4280, there is an *explicit* break in that specific compatibility, and the error message is much cleaner with a version mismatch message. The difference is that the C++ client (unlike the Java client) checks for the server version as well, which make the compatibility break more visible. I am not sure about the plan of action in general about this compatibility. However, I could work around the issue by advertising clients' SASL capability to the server. What do you think? Thank you, Sudheesh [1] https://issues.apache.org/jira/browse/DRILL-4714 On Nov 1, 2016, at 7:49 PM, Laurent Goujon <laur...@dremio.com> wrote: Just for clarity, DRILL-4280 is a breaking-protocol change, so is the plan to defer this change to a later release, or to defer bringing back compatibility between newer clients and older servers to a later release? Laurent On Tue, Nov 1, 2016 at 3:43 PM, Zelaine Fong <zf...@maprtech.com> wrote: Oops, mistake in my notes. For the second item, I meant DRILL-4280, not DRILL-1950. On Tue, Nov 1, 2016 at 3:40 PM, Zelaine Fong <zf...@maprtech.com> wrote: Attendees: Paul, Padma, Sorabh, Boaz, Sudheesh, Vitalii, Roman, Dave O, Arina, Laurent, Kunal, Zelaine I had to leave the hangout at 10:30, so my notes only cover the discussion up till then. 1) Variable width decimal support - Dave O Currently Drill only supports fixed width byte array storage of decimals. Dave has submitted a pull request for DRILL-4834 to add support for storing decimals with variable width byte arrays. Eventually, variable width can replace fixed width, but the pull request doesn't cover that. Dave would like someone in the community to review his pull request. 2) 1.9 release - Sudheesh Sudheesh is collecting pull requests for the release. Some have been reviewed and are waiting to be merged. Sudheesh plans to commit a batch this Wed and another this Friday. He's targeting having a release candidate build available next Monday. Laurent asked about Sudheesh's pull request for DRILL-1950. He asked whether thought had been given to supporting newer Drill clients with older Drill servers. Sudheesh indicated that doing this would entail a breaking change in the protocol, and the plan was to defer doing this for a later release where we may want to make other breaking changes like this.
