Cloud Architecture

Winston Churchill quotes, “We shape our buildings; thereafter they shape us”. We can truly extend this analogy to the cloud too. The way the cloud works, stores, governs, secures and manages user data in its varied forms is dependent on its foundation, its shape – its architecture!

All clouds today barring a few are built on a legacy architecture called a multi-tenant architecture. In the late nineteenth century, cloud services were built on database systems that had a centralized compute, storage and networking common to and serving all customers. Many of the multi-tenant clouds still use the same architecture where users share the infrastructure and software.

This kind of multi-tenancy has its pros and cons:

The multi-tenancy PROS:

• It’s your cost effective cloud as you use shared infrastructure and resources.
• Less time and resources are required to update or upgrade a large number of users at a given Instance.
• It can scale up to support consumer demands and size.
• The cloud provider maintains one shared cloud for all users.
• The users in the multi-tenant environment are always on the latest version of the cloud software.

The multi-tenancy CONS:

• It’s a Dominoes effect! Any action that affects the multi-tenant database affects all shared customers.
• It’s a security hazard as your data is commingled. One breach and everyone can get mauled.
• Customized use of the cloud in a multi-tenancy environment is not possible- very much like a tenant who doesn’t have his own say on where to place a wall cabinet!
• Interrupted Service availability- Multi-tenant architectures rely on large and complex databases that require maintenance on a regular basis. In today’s wired can you imagine living without a service for a few hours every other month with that message popping up on your screen, “The site/service is down as we are doing regular maintenance- Blah! Blah!”
• With multi-tenancy investment needs to be made into application code preventing exposure of data from one client to another.

Moving on to the other spectrum of the architectural prism, there is the multi-instance architecture. The multi-instance cloud architecture is not built on a large central database software and infrastructure. Here, instances are deployed on a per-user basis, allowing the multi-instance cloud to scale horizontally and infinitely. For every client or customer, separate application logic and database processes are deployed. Every customer has a unique set of instances that are dedicated to your organization and needs.

What are the multi-instance pros and cons?

The multi-instance PROS:

• True data isolation as there is no commingling of data. Customers are not bunched together on shared databases and infrastructure.

• The multi-instance environment is secure, stronger and allows for tighter performance SLAs.
• High uninterrupted service availability as customers can be migrated to an on-premise server or to another cloud for routine maintenance and unexpected issues. This fits in well with your need for 24×7 seamless service experiences.
• The multi-instance architecture allows for greater flexibility and control of configuration, customization, updates and upgrades
• There is less risk of harmful attacks that can impact performance, reliability, or data security
• The architecture is simple- easy to deploy, scale and manage in keeping with customer needs.
• It’s a cost effective platform as investments are made into the creation and management of multiple application instances.

The multi-instance CONS:

• It’s harder to install functionality or feature on one instance and then deploy it on all instances.
• There is a cost involved with the tooling to create and configure the environment such as databases and web application instances.

The Winner!

Hands down, in the cloud architecture debate, the multi-instance cloud is the winner especially for a business that values control over their data, systems, customizability and flexibility, as well as being proactively agile to business needs.

This quote by Amelia Boynton Robinson sums it all – “Get off of my shoulders. The foundation has been laid, now it’s time for you to build on it and get to work.”

By Sheetal Kale