A highly available connection that uses a combination of AWS Direct Connect as primary and AWS Site-to-Site VPN as secondary connects on-premises users and systems. Amazon S3 is used for PROS applications to exchange files with upstream and downstream systems. Files are generated after a batch job and stored on Amazon S3 for retrieval. The PROS application comprises an Origin & Destination (O&D) module and a Group Revenue Management System (GRMS) module, accessible only by private IP addresses. Virtual private clouds (VPCs) (production and development environments) are connected via AWS Transit Gateway. The O&D module primary node acts as the access point for users and distributes traffic and jobs to other O&D worker nodes. You can configure primary node manual failover to a worker node or automate primary node failover through an AWS Auto Scaling group and script integration. For worker node failover, you automate failover using Amazon CloudWatch and AWS Lambda. The GRMS module runs in active-passive mode. If the running Amazon EC2 instance fails, a new Amazon EC2 instance is provisioned. You can automate this failover through an AWS Auto Scaling group and script integration. Both O&D and GRMS modules use Amazon RDS for Oracle as the databases, which can be configured into single-AZ deployment (recovered from RDS snapshot) or multi-AZ deployment for high-availability (standby instance has failover capability). Memory-optimized Amazon EC2 R5 instance types handle the memory-intensive O&D database workload. AWS Key Management Service provides D
