[
https://issues.apache.org/jira/browse/KAFKA-14372?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Jeff Kim updated KAFKA-14372:
-----------------------------
Description:
The default replica selector chooses a replica solely on whether the
broker.rack matches the client.rack in the fetch request (and whether the
offset exists in the follower). Here's a scenario where the consumer would not
be able to fetch:
# Cluster is undergoing a rolling upgrade and the follower is shutting down
while the consumer is fetching from follower.
# The connection will gracefully shutdown and the consumer will receive an
error but it will still consider this follower as the preferred read replica
# At the next metadata.max.age.ms (5min default) interval, the follower will
no longer be in the client's metadata so the consumer will reach out to the
leader.
# The leader will redirect the fetch request to the follower, and no progress
is made.
Choosing a replica from the ISR will allow the consumer to make progress at 4.
was:The default replica selector chooses a replica solely on whether the
broker.rack matches the client.rack in the fetch request (and whether the
offset exists in the follower). Even if the broker matching the rack is
unavailable, the consumer will go to that broker. The selector should choose a
broker from the isr.
> RackAwareReplicaSelector should choose a replica from the isr
> -------------------------------------------------------------
>
> Key: KAFKA-14372
> URL: https://issues.apache.org/jira/browse/KAFKA-14372
> Project: Kafka
> Issue Type: Bug
> Reporter: Jeff Kim
> Assignee: Jeff Kim
> Priority: Major
>
> The default replica selector chooses a replica solely on whether the
> broker.rack matches the client.rack in the fetch request (and whether the
> offset exists in the follower). Here's a scenario where the consumer would
> not be able to fetch:
> # Cluster is undergoing a rolling upgrade and the follower is shutting down
> while the consumer is fetching from follower.
> # The connection will gracefully shutdown and the consumer will receive an
> error but it will still consider this follower as the preferred read replica
> # At the next metadata.max.age.ms (5min default) interval, the follower will
> no longer be in the client's metadata so the consumer will reach out to the
> leader.
> # The leader will redirect the fetch request to the follower, and no
> progress is made.
> Choosing a replica from the ISR will allow the consumer to make progress at 4.
--
This message was sent by Atlassian Jira
(v8.20.10#820010)
