...

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: Drafting

Discussion thread: Not ready yet

JIRA: KAFKA-7904

Motivation

Today, a topic partition may be categorized as:

...

In this example, AtMinIsr triggers when there is only 1 insync replica remaining, and tells us that 1 more failure will cause the partition to go completely offline!

Public Interfaces

We will introduce a new metric and a new TopicCommand option to identify AtMinIsr partitions.

ReplicaManager.AtMinIsrPartitions


--at-min-isr-partitions

Proposed Changes

We will add the gauge to Partition.scala:

...

private val reportAtMinIsrPartitionsOpt = parser.accepts("at-min-isr-partitions",
  "if set when describing topics, only show partitions whose isr count is equal to the configured minimum. Not supported with the --zookeeper option.")

private def hasAtMinIsrPartitions(partitionDescription: PartitionDescription) = {
  partitionDescription.isr.size == partitionDescription.minIsrCount
}

private def shouldPrintAtMinIsrPartitions(partitionDescription: PartitionDescription) = {
  opts.reportAtMinIsrPartitions && hasAtMinIsrPartitions(partitionDescription)
}

Compatibility, Deprecation, and Migration Plan

The new TopicCommand option requires use of AdminClient so it will not be available with the --zookeeper option.

Rejected Alternatives

None so far.