protected async override Task ExecuteAsync(CancellationToken cancellationToken)
{
_logger.LogInformation("Job service is starting.");
bool started = false;
while (!cancellationToken.IsCancellationRequested)
{
using (var serviceScope = _services.CreateScope())
{
var scopeServiceProvider = serviceScope.ServiceProvider;
IJobStore jobStore = scopeServiceProvider.GetRequiredService <IJobStore>();
IJobServiceEvents jobServiceEvents = scopeServiceProvider.GetRequiredService <IJobServiceEvents>();
if (!started)
{
await jobServiceEvents.OnStartedAsync();
started = true;
}
JobDescriptor?job;
try
{
job = await jobStore.NextAsync(cancellationToken);
if (job == null)
{
if (!cancellationToken.IsCancellationRequested)
{
throw new Exception("Job store returned null for next job with no cancellation");
}
break;
}
}
catch (TaskCanceledException ex)
{
_logger.LogInformation(ex, "The service was stopped while waiting for a job");
await jobServiceEvents.OnStoppedAsync();
break;
}
catch (Exception ex)
{
_logger.LogError(ex, "An error occurred while waiting for a job");
await jobServiceEvents.OnFailedAsync(ex);
break;
}
try
{
var jobRunner = new JobRunner(scopeServiceProvider);
if (_options.JobTimeout.HasValue)
{
var timeoutCts = new CancellationTokenSource(_options.JobTimeout.Value);
using (var linkedCts = CancellationTokenSource.CreateLinkedTokenSource(cancellationToken, timeoutCts.Token))
{
await jobRunner.RunAsync(job.Call, cancellationToken);
if (cancellationToken.IsCancellationRequested)
{
_logger.LogError($"Job cancelled.");
await jobStore.FailedAsync(job.Id, ex : null);
}
else if (timeoutCts.IsCancellationRequested)
{
_logger.LogError($"Job timed out.");
await jobStore.FailedAsync(job.Id, ex : null);
}
else
{
await jobStore.SucceededAsync(job.Id);
}
}
}
else
{
await jobRunner.RunAsync(job.Call, cancellationToken);
await jobStore.SucceededAsync(job.Id);
}
}
catch (Exception ex)
{
_logger.LogError(ex, $"An error occurred while executing job ID '{job.Id}'");
await jobStore.FailedAsync(job.Id, ex);
await jobServiceEvents.OnFailedAsync(ex);
}
}
}
_logger.LogInformation("Job service is stopping.");
}
