java.lang.OutOfMemoryError: Java heap space

Root cause

The worker exhausted JVM heap. Large records/transactions, connector queues, converters and snapshots can contribute; inspect heap and runtime metrics.

How to fix

1. Measure heap, GC, queue sizes, record sizes and concurrent tasks before choosing a heap budget.
2. Review connector-specific queue and snapshot limits. snapshot.fetch.size is not a universal cap on transaction or converter memory.
3. Check the installed output plugin and connector behavior; do not assume pgoutput or decoderbufs always buffers an entire transaction or always streams one row at a time.