[FLINK-27206] Deprecate reflection-based reporter instantiation

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 1.16.0
• Component/s: Runtime / Metrics
• Labels: pull-request-available

Release Note

Configuring reporters by their class has been deprecated. Reporter implementations should provide a MetricReporterFactory, and all configurations should be migrated to such a factory.
If the reporter is loaded from the plugins directory, setting metrics.reporter.reporter_name.class no longer works.

• Assignee: Chesnay Schepler
• Reporter: Chesnay Schepler
• Created: 12/Apr/22 14:01
• Updated: 24/Nov/22 05:01
• Resolved: 20/Apr/22 20:42

Description

Metric reporters can currently be instantiated in one of 2 ways:
a) the reporter class is loaded via reflection
b) the reporter factory is loaded via reflection/ServiceLoader (aka, plugins)

All reporters provided by Flink use the factory approach, and it is preferable because it supports plugins. The plugin approach also has been available 1.11, and I think it's fair to deprecate the old approach by now.

Issue Links

• causes: FLINK-30183 We should add a proper error message in case the deprecated reflection-based instantiation of a reporter is triggered
• relates to: FLINK-24235 Only support reporter factories for instantiation
• relates to: FLINK-24236 Migrate tests to reporter factories
• links to: GitHub Pull Request #19444