aws network_error ai_generated true

MSK broker unreachable: connection to broker failed

ID: aws/aws-msk-broker-error

Also available as: JSON · Markdown
80%Fix Rate
83%Confidence
50Evidence
2023-01-01First Seen

Version Compatibility

VersionStatusIntroducedDeprecatedNotes
2 active — — —

Root Cause

Client cannot connect to MSK (Managed Streaming for Kafka) broker due to networking, auth, or broker health issues.

generic

Workarounds

  1. 85% success Verify security group allows inbound on Kafka ports from client 
    Check security group allows TCP on ports 9092 (plaintext), 9094 (TLS), 9096 (SASL) from client security group

    Sources: https://docs.aws.amazon.com/msk/latest/developerguide/client-access.html

  2. 82% success Use the correct bootstrap broker string for the authentication method 
    aws kafka get-bootstrap-brokers --cluster-arn ARN to get the correct TLS, SASL, or IAM bootstrap servers

    Sources: https://docs.aws.amazon.com/msk/latest/developerguide/msk-get-bootstrap-brokers.html

Dead Ends

Common approaches that don't work:

  1. Connect to MSK from outside the VPC over the internet 90% fail

    MSK brokers are VPC-only by default; public access requires explicit configuration and is not recommended

  2. Reboot the MSK cluster to fix broker connectivity 65% fail

    MSK reboots replace brokers sequentially and can cause data loss if replication is insufficient

Error Chain

Leads to:
Frequently confused with: