Service Mesh

What is a Service Mesh?

A service mesh is a dedicated infrastructure layer for managing communication between services, typically deployed as a sidecar container next to each service instance. By abstracting away the low-level details of service-to-service communication, service meshes enable developers to focus on business logic while still allowing for fine-grained control over the network.

Service meshes are particularly well-suited for microservices-based architectures, which often consist of hundreds or even thousands of services. The benefits of using a service mesh include improved observability, increased security, and simplified networking.

Types of Service Meshes

There are two common types of service meshes: those that use a sidecar container next to each service instance (referred to as "per-service" meshes), and those that use a proxy container deployed in front of a group of service instances (referred to as "proxy" meshes).

Per-Service Meshes

With a per-service mesh, you simply need to deploy a sidecar container next to each service instance and configure it to communicate with the other sidecar containers in the mesh. Envoy is a popular open source proxy that can be used for this purpose.

Once you have Envoy deployed as a sidecar, you can begin configuring it to route traffic between services. Envoy uses a concept called "clusters" to group together a set of logically similar services. For example, you might have a cluster for all of the services in your e-commerce application, or a cluster for all of the services in your logging infrastructure. Envoy can then be configured to route traffic between these clusters based on a variety of criteria, such as the hostname or path of the incoming request.

In addition to routing traffic, Envoy can also be used to perform other tasks such as service discovery, load balancing, and security. Envoy is highly configurable, and the Envoy team has done an excellent job of documenting all of the available features.

Proxy Meshes

If you're interested in using a proxy mesh, the most popular tool is Istio. Istio is a bit more opinionated than Envoy, and it uses a different approach to routing traffic between services. With Istio, you deploy a proxy container in front of a group of service instances, and the proxy container is responsible for routing traffic between the services.

Istio uses a concept called "virtual services" to group together a set of logically similar services. A virtual service defines a set of policies that should be applied to traffic routed to the virtual service. For example, you might define a virtual service that routes traffic to your e-commerce services based on the path of the incoming request.

Istio also provides a set of tools for monitoring and debugging network traffic. These tools can be extremely helpful when you're trying to troubleshoot issues with your application.

Getting Started with Service Mesh

So, how do you get started with using service mesh in your development projects? If you're just getting started, the per-service approach is a good place to start. Envoy is a popular open source proxy that can be used for this purpose. If you're interested in using a proxy mesh, the most popular tool is Istio. Whichever approach you choose, service mesh can provide a number of benefits for your application, including improved observability, increased security, and simplified networking.