Abstract System workload is shared by different data centers to stay Availability (可用性) and Fault Tolerance (容错性) Things to Note Traffic Redirection Effective tools are needed to direct traffic to the correct data center geoDNS can be used to direct traffic to the nearest data center depending on where a user is located Data Synchronization Users from different regions could use different local Database or Cache Server In failover cases, traffic might be routed to a data center where data is unavailable A common strategy is to replicate data across multiple data centers. Like the asynchronous multi-data center replication by Netflix Test and Deployment Automated deployment tools like Terraform are vital to keep services consistent through all the data centers
