Hi folks, I'd like to start the conversation around 3.0, spurred in part by some compatibility-challenging issues. I'm leading with a somewhat concrete proposal, but that's meant to start the discussion!
Impala's master branch currently self-identifies as version 2.11. (See https://github.com/apache/impala/blob/master/bin/save-version.sh). There's a queue of changes that have enough compatibility concerns that we've been postponing them. (For example, see "Reserving standard SQL keywords next Impala release" in this mailing list.) I propose we create a 2.x branch, and update master to be 3.0, thereby indicating that we'd accept changes with compatibility concerns in master. Both master and 2.x would be active, and, at least for the beginning, changes would automatically be pulled into the 2.x line, unless explicitly blacklisted. After a while, of course, there would be 3.x releases, and 2.x releases would slow down. I've gone through labels IN ("incompatibility", "compatibility") and resolution = "Unresolved" and project=impala <https://issues.apache.org/jira/issues/?jql=labels%20IN%20(%22incompatibility%22%2C%20%22compatibility%22)%20%20and%20resolution%20%3D%20%22Unresolved%22%20and%20project%3Dimpala> in JIRA and here's a short, curated sublist: JIRA Summary Comment IMPALA-4277 Impala should build against latest Hadoop components Strive to make running both possible. IMPALA-3916 Reserve SQL:2016 keywords See thread "Reserving standard SQL keywords next Impala release (IMPALA-3916)" on the mailing lists. IMPALA-6204 Remove DataSourceScanNode at next compatibility breaking point IMPALA-4924 Remove DECIMAL V1 code at next compatibility breaking version Probably switch to DECIMAL_V2 by default, but retain option. IMPALA-4319 Remove unused query options in compat-breaking version IMPALA-4306 Remove deprecated query options at compatibility-breaking version Creating a new branch has the drawback of yet another entity to think about (and cherrypick to), but it seems like we need it to provide a place for changes like those above to land. Thoughts? Thanks! -- Philip
