HealthCheck

Description

Health checks are a set of checks that you perform in order to tell whether an application/service is up, running & healthy or not. Health checks are very useful especially when your application depends on other things like a database or even other services.

NuGet Packages

• AspNetCore.HealthChecks.UI
• AspNetCore.HealthChecks.UI.Client

HealthChecks UI offers several storage providers, available as different nuget packages.

• AspNetCore.HealthChecks.UI.InMemory.Storage
• AspNetCore.HealthChecks.UI.SqlServer.Storage
• AspNetCore.HealthChecks.UI.SQLite.Storage
• AspNetCore.HealthChecks.UI.PostgreSQL.Storage
• AspNetCore.HealthChecks.UI.MySql.Storage

HealthChecks packages include health checks for:

• Sql Server
• MySql
• Oracle
• Sqlite
• RavenDB
• Postgres
• EventStore
• RabbitMQ
• IbmMQ
• Elasticsearch
• CosmosDb
• Solr
• Redis
• SendGrid
• System: Disk Storage, Private Memory, Virtual Memory, Process, Windows Service
• Azure Service Bus: EventHub, Queue and Topics
• Azure Storage: Blob, Queue and Table
• Azure Key Vault
• Azure DocumentDb
• Azure IoT Hub
• Amazon DynamoDb
• Amazon S3
• Google Cloud Firestore
• Network: Ftp, SFtp, Dns, Tcp port, Smtp, Imap, Ssl
• MongoDB
• Kafka
• Identity Server
• Uri: single uri and uri groups
• Consul
• Hangfire
• SignalR
• Kubernetes
• ArangoDB
• Gremlin

Code Snippet

We need to write extension service class code for AddHealthcheckExtensionService inside Extensions folder of API as below,

public static class HealthcheckExtensionRegistration
    {
        public static IServiceCollection AddHealthcheckExtensionService(this IServiceCollection services, IConfiguration configuration)
        {
            services.AddHealthChecks()
            .AddSqlServer(configuration["ConnectionStrings:IdentityConnectionString"], tags: new[] {
                "db",
                "all"})
            .AddUrlGroup(new Uri("http://localhost:61948/healthz"), tags: new[] {
                "weatherApi",
                "all"
            });

            //adding healthchecks UI
            services.AddHealthChecksUI(opt =>
            {
                opt.SetEvaluationTimeInSeconds(15); //time in seconds between check
                opt.MaximumHistoryEntriesPerEndpoint(60); //maximum history of checks
                opt.SetApiMaxActiveRequests(1); //api requests concurrency
                opt.AddHealthCheckEndpoint("API", "/healthz"); //map health check api
            }).AddSqlServerStorage(configuration["ConnectionStrings:HealthCheckConnectionString"]);
            return services;
        }
    }

Now we need to configure AddHealthcheckExtensionService to service in Program.cs class. Please refer to the below snippet which is required to set up HealthChecks UI.

services.AddHealthcheckExtensionService(Configuration);

By default HealthChecks returns a simple Status Code (200 or 503) without the HealthReport data. If you want that HealthCheck-UI shows the HealthReport data from your HealthCheck you can enable it adding an specific ResponseWriter.

app.MapHealthChecks("/healthz", new HealthCheckOptions
{
    Predicate = _ => true,
    ResponseWriter = UIResponseWriter.WriteHealthCheckUIResponse
});

//map healthcheck ui endpoing - default is /healthchecks-ui/
app.MapHealthChecksUI();

Demo

Demo video to get the clear result view of above implemented module.