1. Disaster Recovery as a Cloud Service Chao Liu SUNY Buffalo Computer Science

2.  A typical DR service works by replicating application state between two data centers; if the primary data center becomes unavailable, then the backup site can take over and will activate a new copy of the application using the most recently replicated data. How is DR Done Today?

3.  Recovery Point Objective  The RPO of a DR system represents the point in time of the most recent backup prior to any failure.  Recovery Time Objective  The RTO is an business decision that specifies a bound on how long it can take for an application to come back online after a failure occurs. Disaster Recovery Requirements

4.  Performance  Consistency  Geographic Separation Disaster Recovery Requirements

5.  State replication can be done at one of these layers:  Within an application  Per disk or within a file system  For the full system context  Replication at the application layer can be the most optimized, only transferring the crucial state of a specific application. Disaster Mechanism

6.  The level of data protection and speed of recovery depends on the type of backup mechanism used and the nature of resources available at the backup site.  1. Hot Backup Site  2. Warm Backup Site  3. Cold Backup Site Disaster Recovery

7.  Provides a set of mirrored stand-by servers  These servers are always available to run  Provide minimal RTO and RPO  Synchronous replication  This form of backup is the most expensive  Largest impact on normal application performance Hot Backup Site

8.  Depend on the necessary RPO  Synchronous or asynchronous  It may take minutes to bring them online  Slows recovery, but also reduces cost Warm Backup Site

9.  Data is only replicated on a periodic basis  Servers are not readily available  A delay of hours or days, resulting in a High RTO Cold Backup Site

10.  Detect when a disaster has occurred is a challenging problem.  Cloud based systems can simplify this problem by monitoring the primary data center from cloud nodes distributed across different geographic regions. Failover and Failback

12.  During normal operation, the system stays in Replication Mode.  When a disaster occurs, the system enters Failover Mode. DR as a Cloud Service

13.  Cost Breakdown  99% Uptime Cost  Cost of Adding DR Case Study: Multi-tier Web App

16.  Cost Breakdown  99% Uptime Cost  Periodic Backups Case Study: Data Warehouse

19.  Cloud computing can facilitate disaster recovery by significantly lowering costs  The benefits of virtualization, while not necessarily specific to cloud platforms, still provide important features for disaster recovery Benefits of the Cloud

20.  Handling Correlated Failures  Revenue Maximization Challenges for the Cloud Provider

21.  Network Reconfiguration  Security & Isolation Mechanism for Cloud DR

22.  Cloud computing platforms are an excellent match for providing disaster recovery services due to their pay-as-you-go pricing model and ability to rapidly bring resources online after a disaster.  Better understand what features and optimizations must be included within the cloud platform itself, and to explore the tradeoffs between cost, RPO, and RTO in a cloud DR service. Ongoing Work and Conclusion

23. Thank You