Mesh Control Plane
The component that configures and coordinates a service mesh's data plane proxies, distributing policy, identity and routing rules.
The data plane is the set of proxies that carry traffic. The control plane computes configuration and pushes it to them: which services exist, which routes apply, what policy is in force, and which certificates each workload should present.
The separation has an important operational consequence. A control plane outage does not immediately stop traffic — proxies continue with their last configuration. What stops is change: no new routing, no policy updates, and, critically, no certificate rotation, which means a sufficiently long outage eventually breaks mTLS as certificates expire.
That makes the control plane a statically stable dependency for the data path and a hard dependency for change — the same distinction that governs cloud control planes generally.
What it provides in practice: workload identity issued as short-lived certificates, which is the mesh's most valuable feature and the hardest to build by hand; policy distribution for authorisation, retries, timeouts and circuit breaking; traffic rules for splitting, mirroring and header-based routing; and service discovery.
Operational obligations that follow: the control plane needs its own SLO, its own capacity plan, and a version upgrade path — because a mesh nobody owns becomes the estate's largest liability rather than its security foundation.