[STORM-2783] De-couple "Spout Lag" metrics on Storm UI from Kafka Spout and StormKafkaMonitor

• Type: Improvement
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: 2.0.0, 1.1.1
• Component/s: storm-core
• Assignee: Unassigned
• Reporter: Stephen Powis
• Created: 21/Oct/17 11:14
• Updated: 27/Oct/17 05:43

Description

As a developer of a spout, I'd love to be able to publish lag metrics to the storm UI. After digging into the source code for how the UI interacts with storm-kafka-monitor to get these metrics, it appears to be strongly coupled. I believe that the concept of "Spout Lag" extends beyond the scope of just consuming from Kafka.

I'd like to propose the idea of restructuring how these metrics are queried by StormUI to a way that allows developers of other spouts to be able to "plug into" the UI. The easiest way that springs to mind is to provide an interface that allows developers to code against.