Multi-cloud: A complex strategy with new challenges
Is multi-cloud the right strategy for enterprise businesses?
Multi-cloud dominates the articles by strategy houses and cloud vendors on cloud strategy. Many of these give the impression that a multi-cloud approach is a simple way for an enterprise to spread risk.
In reality, it’s more complicated.
Even Gartner acknowledge "There are many nuances between platforms, and trying to build services in more than one [cloud] simultaneously is challenging."
Every cloud may have a silver lining, but multiple clouds come with many problems. This article explores the challenges of a multi-cloud strategy and looks at a prime cloud strategy as an alternative.
The right way to tackle resilience
A key argument for choosing a multi-cloud strategy is to improve resilience.
The theory is that if your cloud provider has an outage, you can avoid service downtime by failing over to another cloud host.
But in practice, to get that level of resilience for an application, you would have to split your production and disaster recovery across two or more cloud vendors. That’s a significant architectural challenge - engineering critical applications to be resilient across different vendors.
With this complexity, specific applications are likely to need both production and disaster recovery hosted by the same vendor. So a cloud provider outage will still result in critical application downtime. Even if you host different applications with different vendors, this does not protect you from an outage by any individual cloud provider.
What’s the alternative?
Make use of the different regions provided by your cloud host. Even with a prime cloud provider, you can still ensure resilience when there’s an outage in one region by failing over to an unaffected region.
Global balancing within one vendor is going to be easier than trying to have resilient applications hosted across different vendors.
Negotiation tactics vs volume discounts
Many enterprises see multi-cloud as a way to strengthen their bargaining position with cloud vendors. A presence in more than one cloud provider should help you gain a better commercial deal because you always have the option of switching to another vendor.
That’s the belief, but the steps to make this happen are much harder.
For this to be an effective approach it has to be easy to switch applications quickly between vendors. However, cloud technology specialists have highlighted the top technical challenge with switching between vendors is the lack of standardisation for application portability.
Using multi-cloud as a negotiation tool also comes at a cost. When you split your cloud spending across two or more vendors, you miss the chance to realise volume discounts from either vendor. So you’re left paying a higher price to each vendor and are still locked into both services because of the costs of moving.
A different approach is to focus on gaining the best deal with your maximum volumes. A prime cloud vendor strategy gives you the benefits of volume discounts without the overheads of multi-cloud.
Increases in network complexity and cost
Data flows between enterprise applications are a fact of life.
With a multi-cloud strategy, these data flows will inevitably lead to higher network traffic between the different cloud hosts and as a result will push up your network egress costs. Every GB of data that leaves a cloud provider’s network is chargeable. This is another cost of doing business with a multi-cloud strategy.
Hosting your applications across multiple clouds is also going to demand connectivity into more data centres. With each extra cloud that you add to your architecture, you’ll see additional network complexity.
A pandora’s box of third-party tools
Multi-cloud means more than working with multiple cloud vendors.
When an enterprise adopts a multi-cloud strategy, it also has to select and invest in extra third-party tools. These vendor-neutral tools are essential to ensure applications work seamlessly across the different cloud providers.
However, bringing these tools into the operating environment has several impacts.
A desire to avoid vendor lock-in is the reason many enterprises follow a multi-cloud strategy. But the third-party tools that multi-cloud demands introduce the risk of lock-in with a new set of vendors - the third-party tool vendors.
Integrating these critical tools into your architecture is also going to increase its overall complexity. The way these tools operate will have to be factored into future application or architecture changes.
Finally, adding another set of tools and vendors into your ecosystem will push up operating costs. Ensuring interoperability with a multi-cloud strategy comes at the price of these tools.
Target a prime cloud vendor strategy
Multi-cloud has been the strategy in the headlines, but it’s important to be aware of the challenges it creates.
As a result, we recommend enterprises follow a prime cloud vendor strategy instead. This enables you to benefit from volume discounts with your cloud provider. It allows you to create failover solutions within one vendor. You can also avoid the cost of extra third-party tooling and additional network complexity.
When your enterprise needs a specific feature of another vendor, it makes sense to consider only a tactical deployment to that vendor. Your prime vendor is likely to catch up over time, so keep the deployment under review.
Such a prime-vendor cloud strategy helps you simplify your architecture and focus on getting the best deal from your cloud vendor.