Chapter 3. Choosing a Hybrid Cloud Solution
Connecting the private and public clouds is where many organizations stop. The benefits of going further are obvious, but the added complexity can make creating a true hybrid cloud seem too difficult. Although there are solutions available, it can be difficult to find a robust solution offering the necessary level of support and advanced capabilities. This chapter helps with the decision with respect to choosing a hybrid cloud solution that can make deployment of a hybrid cloud much easier.
Examining Capabilities
Several capabilities are necessary in order to provide the level of service necessary in today’s modern organization. When looking at cloud-specific capabilities, these are key ingredients:
Extensive workload support
Advanced resource pooling
Application-centric automation
Connectivity across clouds
Zero-downtime migrations
Extensive Workload Support
Cloud workloads consist of long-running services and short-lived jobs. Although both private and public clouds support both types, providing orchestration and integration for these workloads is challenging.
Best practice dictates running applications on their native platform, regardless of the underlying operating system. Doing so enables the greatest compatibility and performance for a given application. IT staff frequently support various versions of Microsoft Windows and various distributions of Linux, not to mention other Unix variants.
It is no longer uncommon to find multiple operating systems running in support of an individual application. This cross-platform nature of line-of-business applications also facilitates efficiency within the datacenter.
Ideally, a platform with hybrid cloud capabilities would also support the various underlying operating systems and applications necessary for a given workload. Certain products abstract an application into a single-button or low-touch installation.
Advanced Resource Pooling
With a true hybrid cloud platform, resources are abstracted such that applications can execute in the private or public clouds. This is true whether the application runs on another virtualization platform such as vSphere or OpenStack, on a public cloud such as Amazon Web Services (AWS) or Google Cloud Platform (GCP), or within a Docker container.
Applications should also be isolated and partitioned in order to meet security and compliance rules. Ensuring that containers do not run with administrative or root privileges is a key factor in providing security.
Application-Centric Automation
A modern hybrid cloud platform should have capabilities to interact programmatically and automatically. For example, integration points offered through an API can be used to trigger automated processes. The platform should ideally also automatically sense failed nodes and replace as needed.
Beyond failure handling, the hybrid cloud platform should also scale up and down as needed. Scaling is one of the key features of a public cloud platform and having dynamic scaling is useful in a hybrid cloud as well.
Connectivity Across Clouds
The hybrid cloud wouldn’t be much of a hybrid without being able to connect and orchestrate between private and public clouds. The control plane should work with the popular vendors for both cloud types, but it is the orchestration that provides the next level of connectivity.
Zero-Downtime Migrations
A unified interface for connectivity is valuable but is not enough for the next level of automation and control needed by modern organizations. Seamless migration of workloads between private and public clouds is necessary for an organization to truly take advantage of a hybrid cloud.
The migration of workloads should result in zero downtime for the end user. This is achieved by abstracting the infrastructure and by providing that level of abstraction for jobs and services.
Zero-downtime migration is the single most important element in choosing a hybrid cloud solution.
Examining Decision-Making Criteria
There are three criteria that are helpful when examining solutions to the problem of creating a hybrid cloud:
Pricing
Application control
Data locality and regulatory compliance
This section looks at each of those criteria.
Pricing
Many open source packages are available to provide pieces of functionality discussed in this book. Not only do these packages offer access to the source code for customizations, but many times the packages are available at no cost. However, combining many such packages requires another level of care and expertise to achieve the same result as a reasonably priced, single-source solution.
Adding the vital enterprise support and configuration assistance is a differentiator between a self-compiled open source package and one obtained from a vendor. This is notably the case with several large open source projects, for which enterprise support is provided by a vendor who also is an expert in the open source package.
Application Control
Using a single interface and platform for control of an application or workload is another differentiator when looking at hybrid cloud solutions. There is tangible effort involved when working with multiple interfaces and vendors in order to configure a job or service.
Consider this example: to deploy a new service you need to work with database export software, configuration tools, deployment tools, and other elements in order to bring up the service within the private cloud. Making that same service work correctly in the public cloud is no small effort because the tools might be different or at least have a different front-end interface.
Contrast that example with a single control plane from which you can configure and launch a service in either or both clouds and move the service between the clouds without downtime. When looking for a hybrid cloud solution, choose one that has a single, unified interface for application control.
Data Locality and Regulatory
Regulatory compliance is more important than ever. For certain cases, part of that compliance is ensuring that data is homed or stored in the region or country in which it was collected or is to be used. This can be challenging and frequently leads to master data management issues wherein there might be more than one single source of truth for a given data element.
By itself, the hybrid cloud helps with regulatory compliance by facilitating use of public cloud providers located in the desired regions. You then can store data where it needs to be stored in compliance with the necessary regulations and local laws.
However, like other cases, no configuration or built-in template will help create the architecture that is necessary to be compliant. Therefore, it’s up to the system administrators and operations staff to understand and ensure compliance through the use of disparate tools.
Ideally, though, a hybrid cloud solution would help to facilitate the compliant architecture. In much the same way that a single interface makes implementation of a true hybrid cloud better, a single interface can also give the administrator power to move services and jobs around seamlessly. This makes future compliance easier, as well. Not only can the system be compliant with today’s regulations, but as those regulations change, workloads and data can be shifted around as needed to maintain compliance.
Auditing is also part of the compliance landscape. Tracking where and when actions happened with data and services is important. Like other aspects, a hybrid cloud by itself will have no facilities for integrated logging but rather will have logs and audit trails spread over all of the tools used. This makes piecing together what happened and when it happened very challenging.
A solution that uses both a single control plane abstracts the jobs and services in such a way that unified logging and a unified audit trail becomes possible. Collection of that audit trail is much easier and parsing the information to find out what happened and when it happened becomes trivial.
Conclusion
Choosing a solution for a hybrid cloud implementation involves the examination of several criteria. The first of which is typically the workloads themselves: can the proposed solution run the jobs and services that the organization needs to run? After you answer that question, you should evaluate the hybrid cloud solution on how well it does things like pooling of resources and automation. The depth at which a hybrid cloud solution connects between clouds is important. Superficial connections can give the appearance of hybrid behavior while not really providing much substantive assistance to architects and engineers.
The most important element in choosing a hybrid cloud solution is how it handles migrations. Migrations that that you can perform with no noticeable downtime for the end user is the goal. To achieve this goal, the solution needs to have an architecture designed with zero-downtime in mind.
Final decision-making criteria typically includes the cost of the solution along with its ability to control the applications needed by the organization. Many organizations are also affected by data locality and regulatory issues that are a factor in the final decision. The solution you choose must be able to support the regulatory environment in which the organization operates.