Hybrid Cloud: Cloud Rolls Out To Data Centers in Different Hues
The term “hybrid cloud” in popular vocabulary represents a topology in which an organization’s IT infrastructure is spread over public cloud(s) and on-premise data centers. An on-premise datacenter can include the enterprise’s own data center or any colocation facility used by the enterprise. Hybrid has also lately been extended to include edge locations whether in a device or in a telecom provider’s location. These variants are sometimes also referred to as “private cloud.”
Although in a utopian world, the complete data center can be placed in the cloud, in reality, there are invariably some use cases that require workloads to be running on-premise. This is especially true of large enterprises that have considerable IT assets many of which need to continue to reside in the private cloud for various reasons.
Responding to this need, the three major cloud service providers (CSPs) — AWS, Azure and GCP — have released a number of products to enable hybrid cloud computing over the last three to four years. In this post we will look at the positioning of these products in the cloud portfolio of the major vendors along with some common use cases.
Cloud busting is a deployment topology in which the regular traffic is directed to an on-premise deployment by a load balancer. With increasing load, new instances are spun up in the public cloud after the traffic crosses a particular threshold and additional traffic is directed there.
This model is primarily used for cost optimization. A common scenario is to provision additional infrastructure in the public cloud to handle seasonal spikes and scale back or dismantle the same after the traffic returns to normal. This often turns out to be a cheaper option compared to maintaining the same infrastructure on-premise which remains unused during relatively longer periods of regular traffic.
A similar scenario is to use public cloud storage for archival purposes or when the storage requirements exceed the on-premise storage threshold.
Systems running in organizations’ data centers experience unplanned downtimes due to various reasons often causing loss to their business. To mitigate this they plan different levels of disaster recovery strategies depending on the criticality of the system/application. Setting up a disaster recovery site requires building and operating an offsite data center with its associated costs, which often looks like unnecessary overhead. Hybrid cloud gives us the flexibility of operating the disaster recovery infrastructure in public cloud. Both active/passive or active/active strategies can be implemented by leveraging the public cloud.
Organizations often have data governance/residency requirements like PCI-DSS in the cards industry and HIPAA in the insurance sector. These requirements usually prohibit storage of certain category of data in public cloud or beyond geographic boundaries. Hybrid topology enables the organization to get around this restriction by storing the sensitive data on-premise which is sent to the public cloud for storage after applying suitable encryption or aliasing.
Edge computing is the domain of processing data closer to the edge rather than in a central location. There are workloads which require single-digit millisecond latency or even lower. Such workloads need to be placed on-premise at different edge layers to offload some of the processing to the edge and process the traditional workloads in the public cloud.
Some workloads need to operate in remote locations without or with intermittent access to internet and sync with the central servers after entering the range of cellular networks. Use cases for offline execution include ocean liners, IoT devices, cargo carriers.
Network connectivity between cloud provider network and on-premise datacenter can be set up in two different ways:
This allows servers in the on-premise locations to access the public cloud resources and vice versa by private IPs.
