Organizing the Event Queue
Integration via Apache Kafka requires strict management of ordering. Using keyed ordering by object identifier (e.g., order_id) within a single partition guarantees that all changes for a specific order arrive in the correct sequence. To ensure integrity, one should use the idempotent producer available in version 0.11, which minimizes message duplication during retry attempts.
Transactions and External Systems
It is important to understand that Kafka's transactional capabilities apply only to internal broker mechanisms and do not automatically extend to external receiving systems. To avoid data loss during synchronization with CRM or DWH, it is necessary to implement the 'Transactional Outbox' pattern—recording the business operation and the event within a single local database transaction. The rest of the synchronization must support idempotent writes in target systems, where each event is checked for a previously processed identifier. Do not forget to monitor Consumer Lag regularly to respond promptly to stream processing delays.
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