> For the complete documentation index, see [llms.txt](https://docs.serverlessapigateway.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.serverlessapigateway.com/glossary/s/service-mesh.md). # Service Mesh A dedicated infrastructure layer built into an app. This invisible layer facilitates service-to-service communications between services or microservices, using a proxy. A service mesh is a dedicated infrastructure layer that manages service-to-service communication within a distributed application. It uses lightweight network proxies (called sidecars) deployed alongside each service instance to handle traffic routing, load balancing, encryption, authentication, and observability without requiring changes to application code. Popular service mesh implementations include Istio, Linkerd, and Consul Connect. These tools provide features such as mutual TLS encryption between services, circuit breaking, retry logic, traffic splitting for canary deployments, and distributed tracing. The control plane manages configuration, while the data plane (sidecar proxies) handles actual traffic. Service meshes and API gateways serve complementary roles. An API gateway manages north-south traffic (external clients to internal services), while a service mesh manages east-west traffic (service-to-service communication within the cluster). In a microservices architecture, the API gateway handles external concerns like API key validation and rate limiting, while the service mesh handles internal concerns like mutual authentication, traffic policies, and observability between backend services. --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation by asking a question. Perform an HTTP GET request on the following URL with the `ask` and `goal` query parameters: ``` GET https://docs.serverlessapigateway.com/glossary/s/service-mesh.md?ask=&goal= ``` `ask` is the immediate question: it should be specific, self-contained, and written in natural language. `goal` is what the user is ultimately trying to achieve, the reason they need the answer. Sharing it helps GitBook give you a better, more relevant answer. A goal is most helpful when it describes the outcome the user wants rather than restating the question. For example, with `ask=how do I create an API token`, a goal like `automate deployments from our CI pipeline` lets GitBook tailor the answer to that use case. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.