Previous blogs covered the foundational concepts and basic networking requirements to setup an AWS VPC networking with outbound connectivity.
This blog focuses on the hybrid connectivity options and the subsequent blog will be focusing on the design considerations of these connectivity options.
“Enterprise environments are often a mix of cloud, on-premises data centers, and edge locations. Hybrid cloud architectures help organizations integrate their on-premises and cloud operations to support a broad spectrum of use cases using a common set of cloud services, tools, and APIs across on-premises and cloud environments.”
First of all, lets think of why do we need a hybrid connectivity model. The drivers’ use cases to consider such model can vary, to keep it simple, the most common use cases are:
Migration to the cloud: with this scenario, an organization need to have seamless migration without introducing service interruption in which both On-prem DC and the cloud DC/VPC
(s) interconnected during the migration phase to facilitate data transfer, avoid applications down times etc.
Business Continuity: hybrid cloud architectures are a key component of any business continuity solution, where critical data is replicated to the cloud in a different location than the primary system. Data is available in the event of a downtime event, accelerating time to
operations and reducing the costs of such an event. this use case can take different scenarios, such as:
Active – Active
DR as a service: this can take different forms e.g.: cold standby, warm standby, hot standby
Refer to the following AWS blog post for more info
Rapidly recover mission-critical systems in a disaster
Let’s take a moment to define BC and DR as these two labels often used interchangeably while they should not.
Business continuity planning (BCP) is a practice or methodology aims to build and govern a tested and validated plan to maintain key business functions and operations continuity before, during and following a disruptive event. This event could be a natural disaster, human error or technical system failure. We always hear about zero-down time, this actually refers to the continuous availability which is a subset of BC.
Note: the feasibility of considering continuous availability depends on the systems and business criticality. For instance, if the cost of a system’s down time such as in financial services, overweigh the cost of implanting continuous availability, then it will be more feasible to consider redundant systems that help to achieve continuous availability.
On the other hand, Disaster Recovery DR is part of the BC and it’s not another term of BC, DR focuses on the immediate action(s) to contain the impact of an event (failure) on a system and the action(s) involved to recover it.
Speed up innovation/R&D: To support fast growing environments, dynamic organizations, research and development, startups, and others, take a big advantage of the cloud, in which they can perform various experimentation without investing in high upfront costs, systems can scale out and down (elasticity) to handle any increased load, as well as fester time to market with applications’ development in addition to have the ability to utilize cutting-edge functions and services without major efforts e.g. simple API integration to introduce AI functionalities ( e.g. Amazon, Forecast, Personalize, etc.) to their existing services etc.
It is key that the application team to start ‘thinking’ after identifying the IT strategy and applications needs, in which they can mix and match from different applications migration strategies, rather than reverse engineering it (put the applications, then let’s find a work around to connect it back to the On-Prem network). The migration strategies listed below, are based on the 6 R’s that Gartner outlined:
for more details about these migration strategies refer to this AWS blog:
6 Strategies for Migrating Applications to the Cloud
The subsequent blogs will focus on the technical aspects of the hybrid connectivity, starting with the connectivity options, then the key design considerations.