Synchronous online gaming architecutre in AWS - Highly Available, Scalable & Elastic to support Millions of Players

The most important part of designing a database architecture for high performance service at large scale is prioritizing data consistency and availability while ensuring scalability and performance. This means choosing the right database model (relational, NoSQL, etc.) and implementing strategies like data sharding, replication, and caching to handle massive amounts of data and concurrent requests efficiently. This also necessitates careful consideration of indexing, query optimization, and data partitioning to minimize latency and maximize throughput. 

The best balance between read replicas and other database architecture components for high-performance, large-scale services depends on specific workload characteristics. Read replicas excel at offloading read operations from the primary database, improving read performance and scalability. However, they introduce latency for write operations due to data synchronization. Therefore, a balanced approach involves using read replicas strategically for read-heavy applications, implementing caching mechanisms for frequently accessed data, and employing sharding or partitioning to distribute data and improve performance. Ultimately, the optimal architecture requires careful consideration of read/write ratios, latency tolerance, and the specific needs of the application. 

From above diagram, Amazon Elasticache is for Redis that provides fully managed solution that enhances robustness and reduces the cost of installing, operating & maintaining a highly available & scalable Redis cluster. Leverage Multi-AZ Elasticache in your game to provide automated disaster recovery & a scalable tier with read replicas if needed.

Amazon Aurora, a MySQL compatible database provides very high read & write throughput, up to 64TB 6-way replicated storage & up to 15 low latency read replicas in Multi-AZ. We recommend Aurora as a fast, scalable robust database if you are using a relational database like MySQL. Gaming customers have sen 2-3x reduction in cost after migration to Aurora.

Amazon DynamoDB provides predictable performance & scalability by high speed, low latency managed No-SQL database.