RDS and Table Store are suitable for storing session state data for a highly available web application using stateless web servers. RDS provides a relational database management system, which is often used to store session information in a structured format. Table Store provides a NoSQL database service that is optimized for fast read and write operations, making it suitable for session data. OSS is typically used for object storage, which is not ideal for the frequent read/write operations associated with session data. MaxCompute is designed for large-scale data warehousing and analytics, which is also not suitable for session state storage.