Explain how you would design a logging system for a cloud-based application that ensures quick access to logs while maintaining performance and security. What tools would you use?

``` Implement a centralized logging system using tools such as ELK stack (Elasticsearch, Logstash, Kibana) or Splunk, ensuring logs are structured for easy searching and filtering; employ access controls and encryption to address security concerns. Scenario Pressure: How would you handle log retention and regulatory compliance? Depth Trigger: Discuss the implications of real-time logging versus batch logging for system performance. ```