Couchbase utilizes the N1QL language to enable SQL-like queries on JSON data, which is particularly useful when simulating production workloads to test new application performance against required SLAs. Apache JMeter is a versatile, open-source tool for conducting performance tests across various services, including databases and web applications, allowing users to design and execute complex test scenarios while measuring metrics like response time and throughput. The blog discusses setting up test scenarios with JMeter for Couchbase, detailing two specific workloads and demonstrating how JMeter can manage concurrent threads, parameterize queries, and visualize results through various listeners. It highlights the performance differences when running workloads independently versus concurrently, noting that high concurrency can significantly impact response times, as exemplified by the increased latency of complex queries under heavier loads. Additionally, the article mentions other tools such as cbc-pillowfight and YCSB for benchmarking Couchbase and other NoSQL databases.