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Overview

Admin API

An HTTP service for viewing Samaritan's runtime information, include config, stats.

Admin API Reference

Config

Store service configuration, process services and configuration updates, and notify the Controller.

• Static

  Read and parse service configuration from bootstrap file. Work only when init config.

• Dynamic

  The gRPC delivers service and service configuration information.

Controller

Control proc creation, destruction, and runtime behavior.

Proc

The smallest processing unit used to proxy a real service, different protocols can have their own implementation.

Hot Reloader

Responsible for smooth upgrades to Samaritan without downtime, use SO_REUSEPORT.

The new Samaritan instance use UNIX socket to communicate with the old samaritan instance.

sequenceDiagram
   participant new as New Samaritan
   participant old as Old Samaritan
   new ->> old: Dail to UNIX socket
   new ->> new: Start controller
   new ->> old: Shutdown admin request
   old ->> old: Shutdown admin
   new ->> new: Start admin
   new ->> new: Start listeners
   new ->> old: Drain listeners request
   old ->> old: Drain listeners
   new ->> old: Terminate parent request
   old ->> old: Terminate

Workflow

sequenceDiagram
    participant cfg as Config
    participant ctl as Controller
    participant proc as Proc
    cfg ->> ctl: New service event
    ctl ->> +proc: Create new proc
    cfg ->> ctl: Endpoints add event
    ctl ->> proc: Call OnSvcHostAdd()
    cfg ->> ctl: Endpoints remove event
    ctl ->> proc: Call OnSvcHostRemove()
    cfg ->> ctl: Config update event
    ctl ->> proc: Call OnSvcConfigUpdate()
    cfg ->> ctl: Del service event
    ctl ->> -proc: Call Stop()