THIS IS A TEST INSTANCE. ALL YOUR CHANGES WILL BE LOST!!!!
This page is meant as a template for writing a FLIP. To create a FLIP choose Tools->Copy on this page and modify with your content and replace the heading with the next FLIP number and a description of your issue. Replace anything in italics with your own description.
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Document the state by adding a label to the FLIP page with one of "discussion", "accepted", "released", "rejected".
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Please keep the discussion on the mailing list rather than commenting on the wiki (wiki discussions get unwieldy fast).
Motivation
Describe the problems you are trying to solve.
Public Interfaces
Briefly list any new interfaces that will be introduced as part of this proposal or any existing interfaces that will be removed or changed. The purpose of this section is to concisely call out the public contract that will come along with this feature.
A public interface is any change to the following:
Binary log formatThe network protocol and api behaviorAny class in the public packages under clientsConfiguration, especially client configurationorg/apache/kafka/common/serializationorg/apache/kafka/commonorg/apache/kafka/common/errorsorg/apache/kafka/clients/producerorg/apache/kafka/clients/consumer (eventually, once stable)
MonitoringCommand line tools and argumentsAnything else that will likely break existing users in some way when they upgrade
Proposed Changes
FLIP-274: Introduce metric group for OperatorCoordinator introduced a new metric group for source enumerators to emit metrics. However, there is no way from the Flink REST API to fetch these metrics.
The current metric related REST APIs are the following:
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/jobmanager/metrics
/taskmanagers/<taskmanagerid>/metrics
/jobs/<jobid>/metrics
/jobs/<jobid>/vertices/<vertexid>/subtasks/<subtaskindex>
Request metrics aggregated across all entities of the respective type:
/taskmanagers/metrics
/jobs/metrics
/jobs/<jobid>/vertices/<vertexid>/subtasks/metrics |
For example, these APIs allow external services to fetch subtask metrics.
Public Interfaces
The REST API needs to change to support this.
Proposed Changes
Thus, I propose a new REST API
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/jobs/<jobid>/vertices/<vertexid>/operators/<operatorid>/metrics |
with the query parameter get that accepts comma separated metric names, like the other APIs. This path is based on https://github.com/apache/flink/blob/7bebd2d9fac517c28afc24c0c034d77cfe2b43a6/flink-runtime/src/main/java/org/apache/flink/runtime/metrics/dump/QueryScopeInfo.java#L234Describe the new thing you want to do in appropriate detail. This may be fairly extensive and have large subsections of its own. Or it may be a few sentences. Use judgement based on the scope of the change.
Compatibility, Deprecation, and Migration Plan
- What impact (if any) will there be on existing users?
- If we are changing behavior how will we phase out the older behavior?
- If we need special migration tools, describe them here.
- When will we remove the existing behavior?
Test Plan
Describe in few sentences how the FLIP will be tested. We are mostly interested in system tests (since unit-tests are specific to implementation details). How will we know that the implementation works as expected? How will we know nothing broke?
Rejected Alternatives
No compatibility concerns as this is introducing a new API without modifying older APIs.
Test Plan
Unit tests.
Rejected Alternatives
NoneIf there are alternative ways of accomplishing the same thing, what were they? The purpose of this section is to motivate why the design is the way it is and not some other way.