2/28/2023 0 Comments Dark envoy v1.0![]() ![]() ![]() When a request hits one of the listeners in Envoy, that request goes through a set of filters. For example, we could set up the locality of endpoints to keep the traffic local, to send it to the closest endpoint. We can structure the endpoints to prioritize certain instances over other instances based on the metadata. This is where we go from a logical entity of a cluster to a physical IP and port. ![]() We can select an endpoint to send the traffic to. Once we have received the request, we know where to route it (using the routes) and how to send it (using the cluster and load balancing policies). ![]() Clusters are also where we can configure things like outlier detection, circuit breakers, connection timeouts, and load balancing policies. This is all configurable, and we can decide which hosts to include in which clusters. We could have a cluster representing our API services or a cluster representing a specific version of back-end services. Envoy listener, routes, and clusters ClustersĪ cluster is a group of similar upstream hosts that accept traffic. Based on the matching rules in the route, Envoy selects a cluster. Envoy Proxy listener and routesįor example, if the Host header contains the value, we want to route the traffic to one service, or if the path starts with /api we wish to route to the API back-end services. We could look at the request metadata– things like headers and URI path - and then route the traffic to clusters. There can be more than one listener as Envoy can listen on more than one IP and port combination.Īttached to these listeners are routes – routes are a set of rules that map virtual hosts to clusters. Listeners are the way Envoy receives connections or requests. The address and port Envoy proxy listens on is called a listener. To send a request, we need an IP address and a port the proxy is listening on (e.g., 1.0.0.0:9999 from the image above). We are trying to send a request to the proxy, so it ends up on one of the backend services. Let’s say we have the Envoy proxy running, and it’s sending requests through to a couple of services. Let’s explain Envoy’s building blocks using an example. In addition to the traditional load balancing between different instances, Envoy also allows you to implement retries, circuit breakers, rate limiting, and so on.Īlso, while doing all that, Envoy collects rich metrics about the traffic it passes through and exposes the metrics for consumption and use in tools such as Grafana, for example. One of the cool features of Envoy is that we can configure it through network APIs without restarting! These APIs are called discovery services or xDS for short. The idea is to have Envoy sidecars run next to each service in your application, abstracting the network and providing features like load balancing, resiliency features such as timeouts and retries, observability and metrics, and so on. It’s written in C++ and designed for services and applications, and it serves as a universal data plane for large-scale microservice service mesh architectures. Understanding this will help you better understand how Istio works.Įnvoy’s website defines Envoy as an open-source edge and service proxy designed for cloud-native applications. In this blog post, we’ll look at the fundamentals of Envoy: the building blocks of the proxy and, at a high level, how the proxy works. If you’re familiar with Istio, you know that the collection of all Envoys in the Istio service mesh is also referred to as the data plane. Envoy is the engine that keeps Istio running. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |