Kafka UnknownMemberIdException: Why It Happens and How to Fix It
Kafka UnknownMemberIdException — 'The coordinator is not aware of this member' (code 25). Learn the three triggers, the memberId lifecycle, and the exact fix.
Java
107 PostsJava is both a programming language and a platform. Java's WRITE ONCE and RUN ANYWHERE is just too strong. Java is sleeker, faster, and much more powerful today.
Kafka TopicExistsException: Why It Happens and How to Fix It
Kafka TopicExistsException: Topic 'X' already exists. Why AdminClient, Spring KafkaAdmin, and kafka-topics.sh throw it, and how to handle it idempotently.
Kafka TopicAuthorizationException: Not Authorized to Access Topics — Fix
Hitting TopicAuthorizationException: Not authorized to access topics in Kafka? Here's why ACLs deny you, how principals really resolve, and the exact fix.
Kafka TimeoutException: Expiring N record(s) — Cause and Fix
Kafka producer failing with TimeoutException: Expiring N record(s): ms has passed since batch creation? What delivery.timeout.ms really does — and the fix.
Kafka Timeout Before Position for Partition Could Be Determined
Kafka consumer failing with TimeoutException: Timeout of 60000ms expired before the position for partition could be determined? Here's the fix.
Kafka: Timed out waiting for a node assignment — Fix
Kafka AdminClient and kafka-topics.sh fail with 'Timed out waiting for a node assignment. Call: createTopics'. Here's why it happens and the exact fix.
Kafka: Connection Terminated During Authentication — Fix
Kafka AuthenticationException 'terminated during authentication' with its three-reason hint decoded: security.protocol mismatch, TLS/firewall, and mTLS. Repro plus the fix.
Kafka: Subscription to Topics, Partitions and Pattern Are Mutually Exclusive
Kafka throws IllegalStateException: Subscription to topics, partitions and pattern are mutually exclusive when you mix subscribe() and assign(). Here's the fix.
Kafka Streams TaskCorruptedException: Fix and Prevent It
Kafka Streams TaskCorruptedException wipes local state and re-restores from the changelog. Here's why it fires under EOS, how to fix it, and how to stop it.
Kafka Streams: A Serializer Is Not Compatible to the Actual Type
Kafka Streams throws 'A serializer is not compatible to the actual key or value type' or 'ClassCastException invoking Processor'. Here's the SerDe fix.