1. Considerations for operating MS SQL in the cloud, in production, DR, or hybrid scenarios.
By Nick Rubtsov

2. What is a cloud?
Shared hosting
Grid computing
Lots of marketing 

3. Pros of a cloud Low initial cost
Distribution across multiple datacenters, DR/BC
Someone else is responsible for infrastructure
Improved performance (under certain conditions)
Ease and speed of deployment
Ability to easily assign costs
Forces to clean up coding
Supported by all the buzzwords 

4. Cons of a cloud
High sustained cost in production (for larger deployments)
Poor performance (under certain conditions)
Lack of control over the infrastructure and ability to troubleshoot it
Lack of flexibility (you get what everyone else gets)
Cloud-specific idiosyncrasies
Coding mistakes can be critical, and lead to higher expenses

5. Types of clouds
Private
Public

6. Deployment types Cloud-based Hosted in-house Hybrid
Cloud-based with CDN

7. Deployment scenarios and goals
Disaster Recovery and Business Continuity
Moving highly available systems to the cloud
Development and QA
Complete outsourcing to the cloud
Offsite ready backup and cold/hot sites
Pilot projects

8. MS SQL in the cloud: cloud-based vs. hosted in-house
All the pros and cons of cloud-based deployment apply.
Idiosyncrasies – MS Azure hates SQL 
Placement of SQL clients really matters, and can add to expenses
Dedicated WAN links to the cloud are an option
Know your performance metrics and do evaluate your cost!

9. MS SQL in the cloud: hybrid deployment
Geo-cluster (SiOS DataKeeper)
AlwaysOn Availability groups (SiOS DataKeeper)
Database Mirroring
Verify you have enough WAN bandwidth!
Check the latency! You might have to switch from VPN to direct WAN link to access the cloud.

10. 2-node replicated cluster:
Geo-cluster with SiOS
2-node replicated cluster:

11. 3-node cluster with hybrid storage:
Geo-cluster with SiOS
3-node cluster with hybrid storage:

12. 4-node cluster with hybrid storage
Geo-cluster with SiOS
4-node cluster with hybrid storage

13. AlwaysOn Availability Groups with SiOS
Configure the cluster in multinode mode:

14. AlwaysOn Availability Groups with SiOS
Configure availability groups

15. Geo-cluster vs. AlwaysOn
Geo-cluster is easier to administer, but has slower failover, especially over WAN
AlwaysOn fails over faster, but requires more administration (although some of it can be automated)
Database Mirroring can be used, if WFCS cannot be used for some reason.

16. Things to watch out for:
Make sure that the nodes are configured IDENTICALLY! Especially the network names.
Make sure that identical domain policies apply to all nodes, and that these policies are correct.
Make sure your cloud servers have static IPs. Dynamic allocation with reservations isn’t good enough!
Know the infrastructure between your hosted and cloud servers. Make sure that the IPs you think your servers have match what the servers see (due to multiple NATs in the clouds and on your end).
Make sure you have enough bandwidth for your amount of changes, and that the latency isn’t ridiculously high (you might have to change the location of your servers in the cloud, or the cloud, if the latency is high; or get a dedicated WAN link to the cloud).

17. Common mistakes in cloud deployments
Not defining the goals for cloud deployment early on
Not evaluating the performance requirements against the potential solutions
Not researching the cloud as applied to your requirements
Not properly stress-testing the pilot project
Not performing a realistic cost analysis
Listening to cloud’s sales representatives 

18. What to look for in a cloud
Discussion