A specific
pattern used toward hybrid computing involves extending datacenters to the
public cloud. Many companies have significant investments in their immovable
datacenters and while they can create a private cloud such as a VMWare cloud
within the public cloud, they might find it costly to maintain both an
on-premise cloud and one on the public cloud. A reasonable approach between
these choices is to extend the existing datacenters to the public cloud. This
article explores this pattern.
Although technology products are not referred to by their
brands or product names in a technical discussion of an architectural pattern,
it simplifies this narrative by providing a specific example of the technology
discussed. Since many technological innovations are patented, it’s hard to
refer to them without using product names. In this case, we use the example of
a private cloud with VMWare cloud and refer to its products for manageability.
A VMWare vCenter is a centralized management utility that can manage virtual
machines, hosts, and dependent components. VMWare vSphere is VMWare’s
virtualization platform, which transforms datacenters into aggregated computing
infrastructures that include CPU, storage, and networking resources.
The pattern to extend the datacenter to VMWare Cloud on AWS
uses Hybrid Linked Mode. Inventories in both places can be managed through a
single VMWare vSphere Client interface. This ensures consistent operations and
simplified administration and uses a VMWare Cloud Gateway Appliance. It can be
used to manage both applications and virtual machines that are on-premises.
There are two mutually exclusive options for configuration.
The first option installs the Cloud Gateway Appliance and uses it to link from
the on-premises vCenter server to the cloud SDDC. The second option configures
Hybrid Linked Mode from the cloud SDDC. The Hybrid Linked Mode can only connect
one on-premises vCenter Server Enhanced Linked Mode domain and supports
on-premises vCenter Server running more recent versions. When a cloud gateway
appliance is connected to the Hybrid Linked Mode, there can be multiple vCenter
Server connected to the appliance but when the cloud SDDC is directly connected
to the Hybrid Linked Mode, there can be only one vCenter Server.
Different workloads can be migrated using either a cold
migration or a live migration with VMWare vSphere vMotion. Factors that must be
considered when choosing the migration method include virtual switch type and
version, the connection type to the cloud SDDC, and the virtual hardware
version.
A cold migration is appropriate for virtual machines that
experience downtime. These virtual machines can be shut down, migrated and then
powered back on. The migration time is
faster because there is no need to copy active memory. This holds true for
applications as well. A live migration,
on the other hand, uses vMotion to perform rolling migration without downtime and
is advisable for mission critical applications. The idea behind vMotion is that
a destination instance is prepared and made ready and the switching from source
to destination happens near instantaneously.
This pattern establishes promotes the visibility of existing
infrastructure to the cloud.
IT
organizations building a presence in the cloud have a lot in common with the
datacenter operations for a private cloud. There used to be a focus primarily
on the agile and flexible infrastructure which became challenging with the
distributed nature of the applications deployed by the various teams within the
company. The operations of these application stacks evolved with the tools that
transformed how IT operates but these organizations continued to be measured by
the speed, simplicity, and security to support their business objectives.
The speed is a
key competitive differentiator for the customers of any infrastructure – either
on-premises or in the cloud. The leveraging of datacenter locations as well as
the service centric cloud operations model has become mission critical. Fueled
by the transformations in the work habits of the workforce to work from
anywhere at any time, the business resiliency and agility depended on a
connective-fabric network.
The network
connects the on-premises, cloud, and edge applications to the workforce, and it
is a multi-disciplinary effort among NetOps, SecOps, CloudOps, and DevOps
teams. Each one has a perspective into building the infrastructure and the
tools that manage where the workloads are run, the service level objectives
defining the user experience, and implementation of zero trust security to
protect vital business assets.
Enablement of
these teams requires real-time insights usually delivered with an automation
platform. Both the cloud and the datacenter operations can be adapted to the
new normal of shifting workloads and distributed workforces. Delivering a
consistent simplified experience to the teams with such a platform, empowers
them to align and collaborate more efficiently than before. Architectural
patterns and manageability interfaces that unify and simplify these
administrative routines are more than welcomed given the scale of the
inventory.
Some datacenter
automations can be fabric agnostic but they all must have some common
characteristics. These include providing a unified view into proactive
operations with continuous assurance and actionable insights, an orchestrator
to coordinate activities, and a seamless access to network controllers and
third-party tools or services. The orchestrator can also enforce policies
across multiple network sites and enable end-to-end automation across
datacenter and networks. A dashboard offers the ability to view all aspects of
management through a single pane of glass.
It must also define multiple personas to provide role-based access to
specific teams.
Some gaps do
exist between say NetOps to DevOps which can be bridged with a collaborative
focal point that delves into integration such as with ticketing frameworks for
incident management, mapping compute, storage, and network contexts for
monitoring, identifying bottlenecks affecting workloads, and consequent
fine-tuning.
Automation also has the potential to describe
infrastructure as a code, or infrastructure as a resource or infrastructure as
a policy. Flexible deployment operations are required throughout. Complexity is
the enemy of efficiency and tools, and processes must be friendly to the
operators. Automation together with analytics can enable them to respond quickly
and make incremental progress towards their goal.