Marks and Spencer has built up a large IT estate, with legacy systems sitting alongside more modern infrastructure created to support new initiatives over the years – from online sales to banking services.
Managing a complex environment like this can be a challenge for IT staff at the retail firm as it pursues a 'cloud-first' strategy.
"We have a two-mode IT," said Glen Larkin, technical architect at Marks and Spencer, speaking at Cloud Expo in London today. "We have got to a point where the two things have become so large that there is a lot of duplication, so we are going through the challenge now of having to bring those two things together."
The retailer's applications are currently spread across a variety of infrastructure environments. This includes on-premise data centres which use VMware private cloud tools, shared colocation facilities, as well as public cloud vendors Amazon Web Services and Microsoft Azure.
Larkin said that a mix of private and public cloud resources makes sense as part of a longer process to modernise systems.
"Working with the hybrid cloud, it gives you the ability to have a long-term strategy but allow people the ability to do things in the short term," he said.
The migration of workloads to the cloud is happening step by step, with a variety of cloud delivery models considered depending on the application.
"Our cloud strategy puts things in the cloud that are most suited to go into it," said Larkin. "If it is something that we can buy as software as a service then we will.”
"If it is a platform as a service we will get the developers to choose which is the best platform as a service. And then for the infrastructure side of things, some of that will actually need to be transformed before you move it over because it is a different environment."
Workload migrations are being governed by application road maps in place at the company, Larkin explained: "Rather than just letting the cloud organically grow over time, [we have] an application strategy that says that each of these applications is going to be looked at over five years.
"That way your application roadmap will have transformed to the cloud anyway, without that whole drive of 'let's go to the cloud and get everything ready'. It is our strategy that naturally pushes all of the environment to the right cloud. I don't think one cloud is the be all and end all."
For its on-premise systems, M&S has invested in VMware's software defined networking system, NSX, to give it more control over how data is managed internally.
Larkin said: "For a long while everybody thought that if you put everything in one place, you know where it is and it is secure. But in order to do changes and to adapt that in any way, you are always thinking about the application and the infrastructure as a whole."
NSX allows IT staff to put security controls not just around individual applications, Larkin explained, but applications and data ecosystems.
"They are all there together, they can talk to each other, but they are a lot more componentised and things can be more transient than they were before," he said. "That is inherently more secure, it is more flexible as well, by breaking down that monolith of where we are keeping our data."
This means that different applications can be treated differently depending on the need. "So if it is customer data we know we are going to be giving that a lot more rigour than a dev and test workload," he said.
Going forward, Larkin said that Marks and Spencer is looking at containerisation as a way of modernising application delivery. However there will no rush to adopt the technology while both the tools and skills mature.
"We are heading down the containers route, but it is not like it is going to be completely overnight 'everything is containers now'. It is only new things that are going to be looking at that," he said.
"We have applications that are 10 years old and it is going to be a long time before we [replace them]. It is just a learning journey to say the technology is more mature, the skill sets are more mature and the process is well matured. We see the value, but are we going to put the crown jewels onto containers? Not yet, but maybe in a few years."