[FLINK-4054] Inconsistent Reporter synchronization within report()

• Type: Improvement
• Status: Closed
• Priority: Critical
• Resolution: Fixed
• Affects Version/s: 1.1.0
• Fix Version/s: 1.1.0
• Component/s: Runtime / Metrics
• Assignee: Unassigned
• Reporter: Chesnay Schepler
• Created: 10/Jun/16 12:17
• Updated: 10/Jun/16 13:06
• Resolved: 10/Jun/16 13:06

Description

There are currently 2 distinct approaches to how added/removed metrics are handled while a Reporter is in report().

The StatsDReporter simply catches possible exceptions (ConcurrentModificationException/NoSuchElementException) and reports the next time, while all other reporters access the metrics in a synchronized block.

We should have a clear line as to which approach people should use.

Whether FLINK-3998 is a valid issue depends on this decision.