DNS for NFV and 5G: Automatic Scaling and Easy Instantiation

Modern application developments should integrate cloud design principles including meshing, redundancy, horizontal scalability and being event driven. Infrastructure services can follow the same approach for some components that can be distributed. DNS is one of the services that has been designed for meshing, replication, scalability and load sharing. This makes it a really good candidate for Network Function Virtualization (NFV) as seen in telecommunication designs, and especially nowadays in 5G network infrastructures.

Digital transformation has pushed some developments and architecture concepts which have now been adopted by most developers. This helps rapid service deployment, adaptation to the usage and demand, automatic scalability, resiliency and short iterations for software delivery. Some are advocating chaos testing – putting the software in really bad situations to observe how it resists. What seems to be obvious for applications is a bit more complex with infrastructure components, even with the software design approach (SDx) that vendors have been pushing for since many years now. The infrastructure is more central by design, is hard to replace, should not fail, is generally installed for medium to long time periods, and for some in the network space required to run very old protocols that have inherent design constraints for today’s networks.

Virtual Network Functions in 5G networks bring accelerated deployment

In the telecommunications industry, the 5G community would like to do everything in software, this includes a need for network functions that could be virtual. These Virtual Network Functions (VNF) run in virtual environments like any application component for the web industry. With this in mind, any function can be deployed quickly, ideally on the fly, and can scale up and down whenever required by clients. Services deployed as VNF should remain rock solid, manipulate old and complex protocols, be easy to configure, and be able to adapt to any kind of topology which is not entirely what they have been engineered for at their very beginning.

Microservice designs bring scalability

Digital transformation is one thing that can be envisioned using microservices. Infrastructure has been designed with a more traditional and monolithic approach, on single core processors, mainly for improving robustness, efficiency, hardware utilization and overcoming real time constraints. Playing with high speed networking processors, large memory, and real time processing requires a different mindset.

In the microservice world we are helped by the orchestration and virtualization layers that take care of most of the start and stop mechanisms, the scaling complexity and error handling. This is great, but not adapted for infrastructure processes that are required to enable the orchestrator to work. So it’s really a chicken and egg problem. If you need a DNS to start your virtualization infrastructure, don’t put all your DNS engines in virtual machines. Furthermore, monolithic infrastructure applications are not able to start with sub-second delay, or be deployed in multiple instances which would allow them to easily scale up or down. Think about the DHCP and try to make it scale up – keeping address pools consistent will be a really complex process as it requires synchronization. Furthermore, most infrastructure services require rich configuration but not all yet follow a zero-touch approach to help instantiation and scaling.

The current 5G NFV challenge for most network vendors is to bring the best of both worlds: rich applications with monolithic architecture and scalability of microservice designs.

DNS for NFV brings Zero-Touch installation and scaling

DNS is a good candidate for NFV and scaling purposes. It has been designed to be distributed and mainly provides a massive “read” service; the “write” service is asynchronous and is not highly demanding for the underlying infrastructure (compute, storage, network). This is suitable for a CQRS design principle. It can therefore be installed on demand and scale up and down according to technical constraints, or even to internal ones like the number of queries per seconds or recursion delay. The future steps regarding more 5G slices to serve more business requirements and operator offers will imply more complexity and specific requirements for DNS zero-touch installation and scalability.

SmartArchitecture™ makes complex 5G scenarios and usages achievable

EfficientIP has the world’s most powerful DNS in terms of queries per second (QPS) and can serve most telco usages with just a few DNS Blast appliances. To complement this, putting a DNS engine in an VNF is a very interesting architecture pattern that may well serve other usages. We have made some specific developments on automatic installation and automatic scaling up and down of our DNS system in order to comply with the zero-touch paradigm. In addition to automatic startup of an image – which is not really the complex part with evolved systems like OpenStack or even Docker – the interesting part resides in the usage of the SmartArchitecture offered by SOLIDserver. SmartArchitecture for DNS allows advanced preparation of a topology, attachment of all associated configuration, zones, views and parameters, and then addition of DNS engines inside. SmartArchitecture takes care of synchronizing all the configuration aspects and also centralizing the data related to DNS usage.

For NFV, this is exactly the correct approach to take, since the configuration when spinning up a DNS server will automatically be applied from an already running service in a SmartArchitecture and therefore added to the already existing members. Since we can mix high performance hardware appliances and small lightweight packages inside the same SmartArchitecture, even more complex scenarios of the 5G architecture can be realized. The solution brings the required performance, ultra low latency and automatic scaling for occasional events – both planned ones such as time of day or user flows, and unplanned ones like natural disasters. In addition to provisioning and scaling capacities of this VNF flavor, the cache sharing system already available in the DNS Guardian engine allows any new VNF to be immediately operational with a hot-cache directly available upon startup. Therefore the QPS rate able to be delivered is automatically at top level, without any impact on the northbound recursion service.

Align with your business metrics

Lastly, EfficientIP has developed some specific metrics that allow adoption of a well known microservice and scaling principle: qualitative growth scale, which is about the scalability of a service. This allows tie-in with higher-level business metrics rather than only to externally exposed metrics at the hypervision level, like the CPU or the disk and network IOs.

What has been adapted for 5G requirements will also be valuable for other usages. For enterprise and corporate networking, scalability and zero-touch operations are concepts that anyone should embrace, through NFV or any other virtualization approach.