OpenStack is an open-source project that enables enterprises to deploy private clouds, with companies like PayPal and eBay using it for mission-critical services. Due to the complexity and scale of OpenStack environments, continuous logging and monitoring are crucial to preemptively address performance issues. The ELK Stack, comprising Elasticsearch, Logstash, and Kibana, is highlighted as an effective logging platform for this purpose, offering scalability and ease of use. The text provides a comprehensive guide for monitoring OpenStack using ELK, detailing how to retrieve logs via OpenStack's APIs and CLI, and emphasizes the need for authentication tokens. Monitoring is broken down into layers, including hypervisor, server, and tenant metrics, with the importance of RabbitMQ, OpenStack’s default messaging system, also noted. The guide includes configurations for using Logstash and Amazon S3 for log aggregation and shipping, and demonstrates how to build visual dashboards with Kibana to present the collected metrics, thereby enhancing the monitoring and control capabilities of cloud operations teams.