Managing the granular challenges of microservices

As CSPs migrate operations and services to the cloud, microservices – decomposed software-based functions in a system or process run independently on a server or in a container – are enabling many new capabilities. TM Forum’s latest Digital Transformation Tracker found that nearly 90% of CSP respondents are committed to adopting cloud-native technology and a greater percentage have fully committed to cloud-native approaches for all IT workloads (33% today versus 22% a year ago).

But as the reliance on distributed, microservices-based systems grows, a series of challenges are beginning to emerge including scale, increasing complexity and managing performance end to end.

“Microservices need a lot of management and co-ordination, and the degree of orchestration that microservices require is pretty high,” says Mohammad Rubbyat Akram, Vice President, Infrastructure Management at Robi Axiata, a large mobile operator in Bangladesh. Akram advises that “decomposing an already existing system might be a little difficult” and warns that “a microservices architecture, if not properly strategized, can create problems with latency, resulting in poor performance of 5G applications and services.” He notes that such problems will only be magnified as networks become more distributed, cloud-based and ultimately intent-based.

But despite the challenges cloud-native technology and microservices pose, they give enterprises and CSPs common technical benefits that previous iterations of technology could not offer, such as:

• The ability to invoke and re-use functional components easily and in many combinations
• Simplification of new product creation due to reusable components
• Faster and easier fixes and upgrades that do not impact other functional components or business processes
• Exposure of services to third-party applications without complex protocol conversion
• Trading complex protocols for lightweight messaging to communicate between services.

Granular complexity

Achieving the benefits of microservices requires consideration for how processes should be structured, how functions should be decomposed and how much complexity should be introduced at the granular microservices level. TM Forum CTO George Glass argues that there is a point at which functions can become so granular as to be impractical or unmanageable. Initially proponents of microservices thought they would need to decompose systems and processes down to their most atomic or granular degree, but “I don’t see operators or vendors moving in that direction,” says Glass.

Rather, TM Forum Open APIs are structured to allow for granularity in functionality, while exposing less complexity via the APIs. “I might expose an API that’s around appointment management and there are microservices under it for ‘move’, ‘change’, ‘cancel appointment’, and other functions. But no one would buy or consume a ‘change appointment’ microservice on its own, so we have not gone to that level of granularity.”

Glass adds: “Granularity tends to be collections of microservices that make sense and align with Open APIs.”

Microservices everywhere

The main reason CSPs are facing questions relating to functional granularity, architecture and scale is because they are adopting microservices across all areas of their businesses at once. Following are some of the parts of the business where CSPs are driving microservices adoption either overtly or inherently:

Legacy OSS/BSS reconciliation – here microservices give CSPs a new opportunity to access the valuable data stored in and managed well by their legacy systems, like billing and customer relationship management (CRM), without disrupting performance and while migrating away from them. “I’ve seen this behavior used a lot by our members to manage transformation in a controlled manner,” says Glass. “They use Open APIs connected to microservices to get access to legacy data without having to plumb into the legacy applications or move all the data out, then they can move it in a controlled manner over time.”

New software-as-a-service (SaaS) adoption – the commercial model by which CSPs procure software is changing, moving away from long-term fees for licensing, maintenance and customization of monolithic applications toward cloud-native and even SaaS applications. Increasingly these are multi-tenant, single code stream, no-code or low-code configurable and running in public clouds. In our report, How Liberty Latin America revamped to cloud BSS, we looked at how the company is eliminating software customization entirely in favor of cloud-native technology and methodology.

Rollout of 5G standalone core – microservices are at the center of the 5G standalone core specification. “In this new architecture, each network function (NF) offers one or more services to other NFs via APIs,” says Robi Axiata’s Akram. “Each NF is formed by a combination of small pieces of software code, which are microservices.” Microservices allow reuse of 5G NFs, which simplifies implementation and enables independent lifecycle management. That way, “upgrades and new functionalities can be deployed with zero impact on running services,” he explains.

Read our report Microservices: paving CSPs' path to the cloud to find out more about how CSPs are using microservices in operations, networks and services.