Implementing SignalR
Let’s briefly recap how our HealthCheck and HealthCheckAPI projects currently work:
- The 
HealthCheckAngular app features a component—theHealthCheckComponent—that, right after being loaded, performs a call to the server-side/healthendpoint. - The above endpoint is handled by the 
HealthCheckMiddleware: when called, theHealthCheckAPIASP.NET Core Web API is configured to launch various ICMP health checks, each one configured to ping a hostname or IP address and return its status (healthy or unhealthy). - The health checks’ statuses are wrapped together by the 
HealthCheckMiddlewareand sent in a single JSON response. - The 
HealthCheckAngular app fetches the JSON response and uses it to create an HTML table, thus showing the result in a readable format. 
As we can see, the only interaction between the two projects is a single HTTP call issued to the /health endpoint: right after the first health check...