6. Availability, Business Continuity and Disaster Recovery

6.1      Thru Availability

At Thru, we define availability as the continuous accessibility and functionality of our Managed File Transfer service, ensuring uninterrupted operations for our customers. We achieve High Availability through a multi-faceted approach leveraging cloud technologies and robust architectural design. Individual instances of each service that Thru provides can be drained of active sessions and put in maintenance mode.  This allows maintenance to be performed without official maintenance windows.  Our infrastructure is built on leading cloud platforms (AWS or Azure), utilizing their regional availability zones to ensure geographic redundancy. A core architectural principle in our design is ensuring high availability and disaster recovery capabilities across all services. This design allows us to maintain operations even in the event of an entire cloud zone failure, with services continuing to function through redundancy across zones.

 6.1.1     Resilient Storage

Thru utilizes Zone Redundant Storage (ZRS) which synchronously replicates data across three availability zones in the primary Azure region. Each zone operates on independent infrastructure pillars mitigating impact from localized disruptions.

ZRS provides >= 99.9999999999% (12 9s) durability for storage resources over one year.

6.1.2     Resilient Databases

Thru databases leverage Azure SQL Managed Instance and MongoDB configured for geo-redundant storage, with data continuously replicated to a paired region.

6.1.3     Cross-Region Disaster Recovery

The risk of an entire Azure region going down is very low, but still possible in extreme circumstances. Thru’s software-defined architecture enables full environment mobility across regions.

Additional Key features of our availability strategy include:

6.2      Rapid Disaster Recovery

We've prioritized the ability to recover swiftly from potential disasters such as security breaches or VM destruction. Our architecture avoids single points of failure by ensuring no singular VM or box is positioned as an irreplaceable special case.        

6.3      Dynamic Scalability

We can swiftly spawn replacements as needed, allowing for elasticity, and guarding against prolonged downtimes when issues emerge.

6.4      Service Decoupling

 By decoupling service dependencies, we enhance our system's resilience and flexibility.

6.5      Continuous Monitoring

We employ monitoring tools to proactively identify and address potential availability issues before they impact our customers.

6.6      Regular Testing

We conduct regular tests of our high availability and disaster recovery capabilities to ensure their effectiveness.

6.7      Recovery Times

Our commitment to availability is reflected in our Recovery Time Objective (RTO) of 48 Hours and Recovery Point Objective (RPO) of 1 hour, ensuring minimal data loss and quick service restoration in the event of an outage. This approach to high availability and disaster recovery provides our customers with the assurance of business continuity and uninterrupted access to their critical file transfer operations.

6.8      Achieving Cross-Region High Availability

For those requiring high availability spanning Azure/AWS regions, contact our sales team to discuss options.