Logging in ASP.NET Core

[samuraiGH]

how can I log failures that occurred in an asp.net core application?

my code:

builder.Services.AddTempus();
builder.Services.AddTempusJob<NotifyJob>();

[lkinsella]

What kind of failures?

IJobScheduler has a JobError event you can subscribe to for unhandled exceptions, however we tend to have a try...catch within the job itself and inject an ILogger and log there.

[samuraiGH]

What kind of failures?

For example, an exception thrown by the NotifyJob.ExecuteAsync method

IJobScheduler has a JobError event you can subscribe to for unhandled exceptions, however we tend to have a try...catch within the job itself and inject an ILogger and log there.

I think that wrapping every job in try..catch is not the best option. You can use ILogger<JobScheduler> on the library side instead

[lkinsella]

I think that wrapping every job in try..catch is not the best option. You can use ILogger<JobScheduler> on the library side instead

The problem here is you're then creating a hard dependency between the logging framework and ourselves which we wouldn't want to do. As it stands now you're free to choose how you integrate with logging, although as you said the approach could be cumbersome.

We'll give some thought to other mechanisms though, it might be possible to introduce a method into IJob something like this:

class SomeJob : IJob
{
    private readonly ILogger _logger;

    public SomeJob(ILogger<SomeJob> logger)
    {
        _logger = logger;
    }

    public Task ExecuteAsync(JobExecutionContext context)
    {
        // Do some work

        return Task.CompletedTask;  
    }

    public Task ErrorAsync(JobExecutionContext context, Exception ex)
    {
        _logger.LogError(ex, "Unhandled exception.");
    }
}

We could actually expand the arguments out to include a flag to say if it was handled or not etc, but you get the idea.

[samuraiGH]

This is a good option for a class-based job. But what about this code?
builder.Services.AddTempusJob( () => DoThat() )

[lkinsella]

This is a good option for a class-based job. But what about this code? builder.Services.AddTempusJob( () => DoThat() )

Yeh there's no easy solution here I don't think.