What is the control plane?

In its simplest form, the control plane is the brain of a distributed system. It’s the portion that directs, or “controls,” how the rest of the system, commonly known as the data plane, behaves. There are several areas in cloud computing where these control and data planes are referred to. Whether it's networking, Kubernetes, databases, analytics, or overall software as a service architecture, the control plane is the area that orchestrates the processing of the data plane.

The role of the control plane

A distributed system's job is to move data around and process it to accomplish some task or goal. What this means is context-dependent for the system itself. Some examples:

In a cloud networking system

A key function of the control plane would involve creating, managing, and removing virtual networks. These networks are essential for dividing and securely transmitting data across various segments of cloud infrastructure. The flexibility of the control plane to dynamically generate, adjust, and eliminate virtual networks as needed is vital in catering to the scalable and adaptable characteristics of cloud services. 

The control plane would also be responsible for making high-level routing decisions, orchestrating traffic management, and maintaining the overall health and security of the network. This is particularly important in cloud environments, where resources are dynamically allocated, and scalability and flexibility are key.

In a database as a service system

A vital function of the control plane would involve creating, managing, and removing instances and clusters of the database system. It can use cloud infrastructure to dynamically provision compute, storage, and networking resources as needed for customer demand, control all the security configurations specified by the user, and set up the necessary networking connections to allow ingress from public or private networks. The control plane would also orchestrate upgrade, backup, and export processes.

In an analytics as a service system

Analytics systems have similar properties to database systems in that the control plane is responsible for provisioning and managing the data plane infrastructure resources that are responsible for analyzing large amounts of data (including upgrades, security, etc) but the control plane here must also orchestra the execution of analytics tasks themselves. This typically involves scheduling jobs to run on the fleet in the data planes, monitoring and restarting them as necessary, and collecting the results when the jobs are complete.

SaaS companies that provide a service for analyzing or manipulating large amounts of data adopt a Bring Your Own Cloud (BYOC) deployment architecture where the data to be processed lives on the customer's infrastructure. The SaaS provider acts as the control plane as it works with the data in the data plane, which lives in the customer’s infrastructure either on-premise, in the cloud, or both.

Control plane security

The control plane plays a vital role in enforcing security policies and mechanisms. It is responsible for implementing access controls, encrypting data transmissions, and ensuring compliance with security standards. The control plane's ability to centrally manage security policies allows for a consistent and robust security posture across the entire cloud infrastructure.

The evolution of cloud technology has also seen the integration of software-defined networking (SDN) principles into the control plane. The control plane is abstracted from the underlying hardware in an SDN architecture, allowing for more flexible and programmable network management. This separation enables cloud administrators to adaptively and efficiently manage network resources through software, facilitating quicker deployments and more agile responses to changing network conditions.

Learn more about secure ingress to external networks

The control plane in modern cloud architecture is a critical component that governs the routing and management of data in distributed environments. As cloud computing continues to evolve and expand, the role of the control plane becomes increasingly integral, driving the efficiency, scalability, and security of cloud-based services and applications.

If you’d like to learn more about efficiently and securely handling ingress to external networks, we recommend the following from the ngrok blog:

• What is the data plane?
• Unleash the power of ngrok with our Go SDK
• Kubernetes Ingress with ngrok and HashiCorp Consul

Don't hesitate to reach out if you have any questions or encounter any issues. Connect with us on Twitter, the ngrok community on Slack, or contact us at support@ngrok.com. 

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