[KAFKA-5096] Only log invalid user configs and overwrite with correct one

• Type: Improvement
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Fix Version/s: 1.0.0
• Component/s: streams
• Labels: beginner newbie
• Assignee: Mariam John
• Reporter: Matthias J. Sax
• Reviewer: Matthias J. Sax
• Created: 20/Apr/17 15:34
• Updated: 02/Aug/17 13:12
• Resolved: 02/Aug/17 13:11

Description

Streams does not allow to overwrite some config parameters (eg, enable.auto.commit) Currently, we throw an exception, but this is actually not required, as Streams can just ignore/overwrite the user provided value.

Thus, instead of throwing, we should just log a WARN message and overwrite the config with the values that suits Streams. (atm it's only one parameter enable.auto.commit), but with exactly-once it's going to be more (cf. KAFKA-4923). Thus, the scope of this ticket depends when it will be implemented (ie, before or after KAFKA-4923).

This ticket should also include JavaDoc updates that explain what parameters cannot be specified by the user.

Issue Links

• is related to: KAFKA-4923 Add Exactly-Once Semantics to Streams
• links to: GitHub Pull Request #2938
• links to: GitHub Pull Request #2990