private async Task <HealthReportEntry> RunCheckAsync(IServiceScope scope, HealthCheckRegistration registration, CancellationToken cancellationToken)
{
cancellationToken.ThrowIfCancellationRequested();
var healthCheck = registration.Factory(scope.ServiceProvider);
// If the health check does things like make Database queries using EF or backend HTTP calls,
// it may be valuable to know that logs it generates are part of a health check. So we start a scope.
using (_logger.BeginScope(new HealthCheckLogScope(registration.Name)))
{
var stopwatch = ValueStopwatch.StartNew();
var context = new HealthCheckContext {
Registration = registration
};
Log.HealthCheckBegin(_logger, registration);
HealthReportEntry entry;
CancellationTokenSource timeoutCancellationTokenSource = null;
try
{
HealthCheckResult result;
var checkCancellationToken = cancellationToken;
if (registration.Timeout > TimeSpan.Zero)
{
timeoutCancellationTokenSource = CancellationTokenSource.CreateLinkedTokenSource(cancellationToken);
timeoutCancellationTokenSource.CancelAfter(registration.Timeout);
checkCancellationToken = timeoutCancellationTokenSource.Token;
}
result = await healthCheck.CheckHealthAsync(context, checkCancellationToken).ConfigureAwait(false);
var duration = stopwatch.GetElapsedTime();
entry = new HealthReportEntry(
status: result.Status,
description: result.Description,
duration: duration,
exception: result.Exception,
data: result.Data);
Log.HealthCheckEnd(_logger, registration, entry, duration);
Log.HealthCheckData(_logger, registration, entry);
}
catch (OperationCanceledException ex) when(!cancellationToken.IsCancellationRequested)
{
var duration = stopwatch.GetElapsedTime();
entry = new HealthReportEntry(
status: HealthStatus.Unhealthy,
description: "A timeout occured while running check.",
duration: duration,
exception: ex,
data: null);
Log.HealthCheckError(_logger, registration, ex, duration);
}
// Allow cancellation to propagate if it's not a timeout.
catch (Exception ex) when(ex as OperationCanceledException == null)
{
var duration = stopwatch.GetElapsedTime();
entry = new HealthReportEntry(
status: HealthStatus.Unhealthy,
description: ex.Message,
duration: duration,
exception: ex,
data: null);
Log.HealthCheckError(_logger, registration, ex, duration);
}
finally
{
timeoutCancellationTokenSource?.Dispose();
}
return(entry);
}
}
/// <summary>
/// Runs the health check, returning the status of the component being checked.
/// </summary>
/// <param name="context">A context object associated with the current execution.</param>
/// <param name="cancellationToken">A <see cref="CancellationToken"/> that can be used to cancel the health check.</param>
/// <returns>A <see cref="Task{HealthCheckResult}"/> that completes when the health check has finished, yielding the status of the component being checked.</returns>
public Task <HealthCheckResult> CheckHealthAsync(HealthCheckContext context, CancellationToken cancellationToken = default) => _check(cancellationToken);
public Task <HealthCheckResult> CheckHealthAsync(HealthCheckContext context, CancellationToken cancellationToken = default)
{
return(Task.FromResult(HealthCheckResult.Healthy()));
}
public override async Task <HealthReport> CheckHealthAsync(
Func <HealthCheckRegistration, bool> predicate,
CancellationToken cancellationToken = default)
{
var registrations = _options.Value.Registrations;
using (var scope = _scopeFactory.CreateScope())
{
var context = new HealthCheckContext();
var entries = new Dictionary <string, HealthReportEntry>(StringComparer.OrdinalIgnoreCase);
var totalTime = ValueStopwatch.StartNew();
Log.HealthCheckProcessingBegin(_logger);
foreach (var registration in registrations)
{
if (predicate != null && !predicate(registration))
{
continue;
}
cancellationToken.ThrowIfCancellationRequested();
var healthCheck = registration.Factory(scope.ServiceProvider);
// If the health check does things like make Database queries using EF or backend HTTP calls,
// it may be valuable to know that logs it generates are part of a health check. So we start a scope.
using (_logger.BeginScope(new HealthCheckLogScope(registration.Name)))
{
var stopwatch = ValueStopwatch.StartNew();
context.Registration = registration;
Log.HealthCheckBegin(_logger, registration);
HealthReportEntry entry;
try
{
var result = await healthCheck.CheckHealthAsync(context, cancellationToken);
entry = new HealthReportEntry(
result.Result ? HealthStatus.Healthy : registration.FailureStatus,
result.Description,
result.Exception,
result.Data);
Log.HealthCheckEnd(_logger, registration, entry, stopwatch.GetElapsedTime());
Log.HealthCheckData(_logger, registration, entry);
}
// Allow cancellation to propagate.
catch (Exception ex) when(ex as OperationCanceledException == null)
{
entry = new HealthReportEntry(HealthStatus.Failed, ex.Message, ex, data: null);
Log.HealthCheckError(_logger, registration, ex, stopwatch.GetElapsedTime());
}
entries[registration.Name] = entry;
}
}
var report = new HealthReport(entries);
Log.HealthCheckProcessingEnd(_logger, report.Status, totalTime.GetElapsedTime());
return(report);
}
}