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This page is meant as a template for writing a KIP. To create a KIP choose Tools->Copy on this page and modify with your content and replace the heading with the next KIP number and a description of your issue. Replace anything in italics with your own description.
Status
Current state: "Under Discussion"
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Please keep the discussion on the mailing list rather than commenting on the wiki (wiki discussions get unwieldy fast).
Motivation
In managed Kafka service world, the service provider needs a way for billing the customer by the network usage inbound/outbound. To do that we have the following options:
- Counting the network usage via the metrics in other component, ex: proxy software like nginx, HAProxy. That works, but while there will be some over-counted number because not every network package entering Kafka in the end, ex: when an IP is rejected by the proxy software, or authentication failure... etc. But all the package flow will be counted into the metrics in proxy software.
- Using the
BrokerTopicMetrics
in Kafka.Description Mbean name Normal value Byte in from clients kafka.server:type=BrokerTopicMetrics,name=BytesInPerSec,topic=([-.\w]+) Byte in (from the clients) rate per topic. Omitting 'topic=(...)' will yield the all-topic rate.
Currently, Kafka has exposed request size in bytes by request type:
Description | Mbean name | Normal value |
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Request size in bytes | kafka.network:type=RequestMetrics,name=RequestBytes,request=([-.\w]+) | Size of requests for each request type. |
But the metrics is in "histogram" type, so it needs further process to sum all the data.
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.
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Binary log format
The network protocol and api behavior
Any class in the public packages under clientsConfiguration, especially client configuration
org/apache/kafka/common/serialization
org/apache/kafka/common
org/apache/kafka/common/errors
org/apache/kafka/clients/producer
org/apache/kafka/clients/consumer (eventually, once stable)
Monitoring
Command line tools and arguments
- Anything else that will likely break existing users in some way when they upgrade
Proposed Changes
Describe 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 KIP 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
If 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.