Status

Current state: Under discussion

Discussion thread:

JIRA:

Please keep the discussion on the mailing list rather than commenting on the wiki (wiki discussions get unwieldy fast).

Motivation

Currently, we have the following metrics per broker.

kafka.server:type=BrokerTopicMetrics,name=BytesInPerSec

kafka.server:type=BrokerTopicMetrics,name=BytesOutPerSec

The issue is that the former accounts for traffic from the producer client, but the latter accounts for traffic from the consumer client as well as internal replication. This inconsistency can be confusing. The same issue exists for the same metric at the topic level.

Public Interfaces

Proposed Changes

The proposal is to make the metrics more consistent. First, the existing metric kafka.server:type=BrokerTopicMetrics,name=BytesOutPerSec will be changed to only account for traffic from the consumer. The same change applies to the BytesOutPerSec metric at the topic level too. A new metric kafka.server:type=BrokerTopicMetrics,name=ReplicationBytesOutPerSec will be added to account for traffic from the internal replication. The ReplicationBytesOutPerSec metric won't be at the topic level.

Compatibility, Deprecation, and Migration Plan

Users who are tracking the BytesOutPerSec metric will need to understand that the meaning of the value has changed.

Rejected Alternatives