What every database professional needs to know about cloud migration

What is the cloud?

In 1961, Professor John McCarthy was the first to publicly suggest in a speech at the centennial celebration of the Massachusetts Institute of Technology that: "Computing may someday be organized as a public utility just as the telephone system is a public utility. Each subscriber needs to pay only for the capacity they actually use, but they have access to a very large system. Certain subscribers might offer service to other subscribers. The computer utility could become the basis of a new and important industry."

Characteristics: Location-independent resource pooling, measured service, on-demand self- service provisioning, rapid elasticity, and ubiquitous network access.

Reasons to migrate to the cloud: Always-on architecture, automatic monitoring and management, enterprise-class security, fast access to range of resources, integrated disaster recovery, optimized infrastructure, and simplified IT operations.

Deployment models: (1) Private cloud: Resources dedicated to a single customer. (2) Public cloud: Resources shared by multiple customers. (3) Hybrid cloud: Combination of shared and dedicated resources. (4) Community cloud: Resources dedicated to a group of customers.

Service delivery models: (1) Software as a service (SaaS): Enables a user to use and application without installing it on a computer or other type of device. For example, cloud virtualized application. (2) Platform as a service (PaaS): Allows third parties to build applications without buying hardware or maintaining software. For example, cloud virtualized databases. (3) Infrastructure as a service (IaaS): Provides hardware capacitates as demanded by users to run their software services. For example, cloud virtualized machines.

Ownership:

- | dedicated | infrastructure as a service | platform as a service | software as a service

applications | customer | customer | customer | cloud provider

data | customer | customer | customer | cloud provider

middleware | customer | customer | cloud provider | cloud provider

operating system | customer | customer | cloud provider | cloud provider

servers | customer | cloud provider | cloud provider | cloud provider

storage | customer | cloud provider | cloud provider | cloud provider

networking | customer | cloud provider | cloud provider | cloud provider

Locations of databases:

- | on-premises | hosted off-premises | public cloud

resources | dedicated | dedicated | shared

databases on physical machines | yes | yes | no

databases on virtualized machines | yes | yes | yes

databases in private cloud | yes | yes | no

cloud virtualized databases | no | no | yes

Barriers to cloud migration: Cost for migrating from entrenched technology, fear of major change, preference for established infrastructure, regulatory compliance, security, and trust in stability of cloud provider.

Security concerns: Consistent policies across all systems, data privacy, data protection (encryption and destruction), identify and access, network security, sensitive data discovery and classification, threat defense (updates, monitoring, and testing), and vulnerability scanning and management.

Benefits: Agile, cost-effective, efficient, flexible, interoperable, predictable performance, reliable, scalable, secure, and time-saving.

Disadvantages: (1) Lack of insight into the underlying systems when troubleshooting problems. (2) Lack of options for scaling when not fitting into prescribed offerings of cloud provider. (3) Lack of service due to small ratio of number of staff at cloud provider versus number of customers. (4) Risk of inconsistent performance due to lack of shared resources.

Challenges: (1) Acquire skills to take advantage of cloud. (2) Create processes to drive line-of-business cloud speed. (3) Exceed budget for cloud. (4) Lack tools and processes to manage new procurement model. (5) Move from capital expenditure to operating expenditure. (6) Suffer from cloud failure due to human errors.

Steps for cloud migration:

(1) Adopt: Perform business case analysis, determine requirements, and select service providers.

(2) Prepare for deployment: Develop migration plan, decide architecture, and determine integration requirements.

(3) Deploy: Prepare systems, migrate together with cloud provider, and verify migration.

(4) Monitor: Setup tools, set thresholds and benchmarks, and monitor and adjust tools.

(5) Manage: Engage administrative processes, adapt to cloud-specific details, and review procedures periodically.