Answer: Hadoop/Spark deployed using Cloud Dataproc Regional in High Availability mode

The question asks which compute services can be migrated 'as-is' while maintaining an optimized architecture for performance in the cloud. Based on the community discussion and Google Cloud best practices: - Option C (Hadoop/Spark deployed using Cloud Dataproc Regional in High Availability mode) is the correct answer. Cloud Dataproc is Google's managed Hadoop/Spark service that allows migration of existing Hadoop/Spark workloads with minimal changes, providing an optimized, managed environment with built-in high availability. This aligns with the 'as-is' requirement while leveraging cloud optimization. - Option A (Web applications using App Engine standard) is incorrect because the case study mentions custom configurations (Tomcat/Nginx) that may not be compatible with App Engine standard without modifications. - Option B (RabbitMQ using unmanaged instance groups) is suboptimal as Google Cloud recommends Pub/Sub for message queuing, and unmanaged instance groups require manual management, which isn't optimized for cloud. - Option D (Jenkins, monitoring, bastion hosts, security scanners) is incorrect because these services have better cloud-native alternatives (e.g., Cloud Build for Jenkins, Stackdriver for monitoring, Cloud IAP for bastion hosts) that would require changes rather than 'as-is' migration. The community consensus strongly supports C, with the highest upvoted comments (30 upvotes) and detailed reasoning highlighting Dataproc as the ideal 'as-is' migration path for Hadoop/Spark workloads.

Author: LeetQuiz Editorial Team