Cloud based services have become the norm. Your services are in the cloud, your data is in the cloud, your logs are in the cloud. What are the new challenges and concerns with this approach?In this talk, SpectX will share its data-driven research into the reliability and trustworthiness of S3 server access logs. How does S3 server access logging work? How does Amazon’s best-effort log delivery look like in practice? When and how should you analyse the logs? What should you ask? Can you trust the results? If not – what’s the workaround?