ANZ continues to re-architect its "monolith" applications

ANZ Banking Group is continuing to break down "monolithic" applications in its environment, having seen improvements to stability and availability from its transformation work to date.

Product area lead for digital channels in institutional technology, Peter Tsatsaronis, told a recent Red Hat Summit in Sydney that the bank had spent “the last couple of years” rearchitecting monolithic applications to be composed of microservices and API-based services instead.

Work is continuing, both with applications that have already been rearchitected as well as others that have been identified as transformation candidates.

"There's still monolithic applications that we need to transform," Tsatsaronis said.

Of those that have been transformed, Tsatsaronis noted that some tweaking of the architecture is still taking place.

"We talked about breaking down the monolith, but how small do you go? How small is too small?" he said.

"If you break them down too small, you get to this maintenance nightmare. If you don't break it down enough, you don't necessarily get the benefits that you're looking for.

"So that was one of our biggest challenges, and the way we overcame those challenges was [by exploring] what logically made sense for breaking down the application. What are some of the common services? What are some of the features that we can break out that actually makes sense?"

The bank had also learned from customer behaviour, once the rearchitected application was in production, since these were hard to simulate in test.

"With the [behavioural] data coming back, we actually learn and evolve and it's like, 'We should break down that service a little bit of more', or 'We probably broke that up a little bit too much. If we converge a couple of these here, we get some synergies'.

"So we're continuing to evolve how we break down the monolith as we learn more and more about the customers behaviour and about these applications."

Tsatsaronis said that both the bank and its customers benefited from the re-architected apps, with benefits in the areas of stability, reliability and increased cadence of new feature delivery.

In previous incidents, applications were "either up or down"; when they were down, customers could not login or transact at all.

The use of a microservices architecture now means problems can be isolated to a specific service or component, meaning other parts of the application remain functional.

"What we're finding now with the more services-based architecture is we can now have customers still logging in," Tsatsaronis said.

"If we have an incident, we might have one or two functions not working but the customer can still fulfill 90 percent of what they were wanting to do."

Tsatsaronis said that incident numbers were lower generally and that stability and availability measures had improved.

In addition, new features can be delivered to production much faster, in part because the number of engineers and squads that can work with the application is much higher now that the architecture has changed.

"Previously, it was only certain number of teams and engineers that could work on a particular monolith application, whereas now that we've gone to a microservices-type architecture, we've got the ability to have multiple squads working on multiple services in parallel," he said.

"We're really seeing a big uptake in our feature delivery by moving to this new architecture as well."

Tsatsaronis said that further benefits could accrue when more of the microservices and applications are migrated to run in the cloud, instead of on on-premises infrastructure.

OpenShift migration

At the conference, ANZ Banking Group also revealed details of a version upgrade to its Red Hat OpenShift environment.

Red Hat OpenShift 3.11 was "approaching end of life" requiring it to move up to OpenShift 4, which it did with help from the vendor's consulting arm.

As part of the project, the bank also used a tool called Red Hat Service Interconnect to "more securely connect applications across [OpenShift] environments, enabling developer teams to move them as they were ready".

According to Red Hat and ANZ, "This resulted in a streamlined migration" and maintained "uninterrupted transactions for the bank’s retail and commercial customers."

The bank picked up a vendor award for the project.

Tsatsaronis said there are additional possible use cases to explore around the Interconnect service, beyond the migration one for which it was initially used.