An Instana administrator is documenting all backend architecture components for a security compliance audit and must explain each component's function. What is the primary function of Apache Zookeeper in the Instana backend infrastructure?

Apache Zookeeper provides the distributed coordination layer for the Kafka cluster in the Instana backend, handling broker registration, leader election for Kafka partitions, and configuration synchronization. Without a healthy Zookeeper ensemble, the Kafka cluster cannot elect partition leaders and the entire metrics pipeline is disrupted. Trace storage is handled by ClickHouse, service maps by Elasticsearch, and agent authentication by the Instana backend server. The correct answer is 'Providing distributed coordination, configuration management, and broker registration for the Kafka cluster'. The incorrect options — 'Storing raw application traces and span data received from instrumented services', 'Indexing monitored service endpoints and relationships to power the Instana service map', 'Managing Instana agent authentication tokens and TLS certificate rotation' — are wrong because they do not align with IBM Instana's architecture or recommended practices for this scenario. Understanding this concept is essential for the Domain 5: Planning domain of the IBM Instana Observability certification.