It is likely that you have heard of the five approaches to consider when migrating applications to a cloud vendor: rehost, refactor, revise, rebuild, and replace. But what about focusing on the database tier, which tends to be overlooked. Data base administrators (DBAs) are no different than most people where changes are concerned. After all, they are knowledgeable and comfortable with the data base management system (DBMS) they currently use. If the same DBMS is used in a cloud environment, the change threshold is limited to learning how to operate in a cloud environment (considerably less effort). If you adopt a new DBMS, though, the impact will be greater.
The various service options from a cloud vendor provide opportunities to reassess business needs to determine if a DBMS switch should be considered. Will switching to a different DBMS provide a better platform to achieve future business goals? Difficult to answer, but consider these potential advantages to switching:
- Reduced costs
- Options for a fully managed environment with guaranteed SLAs
- Options to create separate reporting databases (reducing production database load)
- Expanded DBMS capabilities (e.g., data types such as semi or unstructured data)
- Better durability options
- Better security options
These are not guaranteed and will vary depending on the cloud vendor and DBMS implemented. Also consider that the current DBMS used may not be fully optimized so a thorough review should be conducted prior to deciding to switch.
If migrating to a new DBMS is considered, initial concerns are likely to center on impacts to data, schema (structure), and functionality. Several cloud vendors offer services to minimize these concerns. Which service/approach is chosen partially depends on the amount of source data and the amount of allowable downtime for the migration. Ignoring the application and web tiers in this discussion, services exist to migrate the bulk of the data and keep it current with the on-premises system. Using this approach allows business teams (and IT) to review and get fully prepared to switch to the new production system (and can provide validation/testing time, time for last-minute modifications, etc.) There still may be some application downtime when the switch occurs, but sincethe data is constantly refreshed, an appropriate time frame can be chosen to minimize the impact. The result is a new underlying DBMS, possibly offering many more capabilities to expand the application and provide unrealized opportunities for the business teams.
Cloud migration to a new DBMS potentially offers better durability, better security, increased functionality, and scalability unmatched with on-premises environments. Cloud vendors also provide fully managed environments as an option to consider. Migrating a legacy environment deserves time for a thorough architectural review. The various DBMS options provided by cloud vendors are just one, and potentially very important, aspect of a migration effort.
Dan Kempton is the Sr. IT Advisor at North Carolina Department of Information Technology. An accomplished IT executive with over 35 years of experience, Dan has worked nearly equally in the private sector, including startups and mid-to-large scale companies, and the public sector. His Bachelor’s and Master’s degrees in Computer Science fuel his curiosity about adopting and incorporating technology to reach business goals. His experience spans various technical areas including system architecture and applications. He has served on multiple technology advisory boards, ANSI committees, and he is currently an Adjunct Professor at the Industrial & Systems Engineering school at NC State University. He reports directly to the CIO for North Carolina, providing technical insight and guidance on how emerging technologies could address the state’s challenges.
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