Hi Yuepeng,
Thanks, line-level answers it.
I scanned the full source tree of 13 release tags plus current master
instead of individual files, because these keys move between classes
(schema-registry.subject passed through three). On master there are 23
withFallbackKeys sites: 9 pass a string literal, 14 reference another
option's key. That split is mechanical, so the two categories you want
separated can be told apart without judgement. The 9 literal sites cover
7 keys:
schema-registry.url option until 1.13, fallback since 1.14
schema-registry.subject option until 1.17 (last in the Kafka
connector), fallback only since 1.18
schema-registry.schema never an option, fallback since 1.18
web.address option until 1.20, marked @Deprecated for
years, fallback since 2.0
s3.access.key never an option, fallback since 2.0
s3.secret.key never an option, fallback since 2.0
s3.path.style.access never an option, fallback since 2.3
So the s3 keys are recent, and s3.path.style.access only appeared in
2.3, which settles those: leave them. web.address did carry a
deprecation marker while it was still an option. schema-registry.url is
the one that stands out, a silent fallback for about ten releases and
never marked deprecated.
Best regards,
Sai Krishna Sepuri
