Most exceptions are logged as System.AggregateException

Running with .NET 4.7.2, with heavy use of Parallel.ForEach. After moving to sentry-dotnet from Raven, most of our exceptions now show up in Sentry dashboard as “System.AggregateException: One or more errors occurred.”. Raven used to unpack those if there was just a single inner exception, which made the dashboard a lot more “glanceable”.

Now I understand this might be an explicit design choice not to unpack them: in this case, could you please provide a code sample how to preprocess them in the client code (I’m guessing somewhere with filters?)

[bruno-garcia]

Although some of .NET’s API will wrap exceptions inAggregateException, simply because more than one exception could have happened at that point (i.e TPL), it’s also a valid scenario for a user to throw it’s own instance, with a meaningful message and location (stacktrace). Also, a catch block in between the throw and Sentry capturing it could have added useful stuff into Data. That would also be lost if we simply dropped the AggregateException

With that in mind, it was a design idea to not throw this information away automatically but perhaps shortsighted as for many usages of the TPL like yours this is likely noise only.

It’s a fair request to add the possibility to drop AggregateException altogether by default (on 2.0.0 which is breaking) although that will affect event grouping and could be a showstopper to many, I’m afraid.

Another option is to add an opt-in: UnwrapOnlyAggregateException or something with a much better name.

Code doing all that is here:

https://github.com/getsentry/sentry-dotnet/blob/c77736679b500f7cc7ad760d0274f2f703d7b34c/src/Sentry/Internal/MainExceptionProcessor.cs#L65-L102

In case you or someone else in the community like to help with a PR proposing a change. I’d be happy to review and discuss it further.

Until then:

The work around you’re looking for would look like this:

private class NoAggregateExceptionSentryEventProcessor : ISentryEventProcessor
{
    public SentryEvent Process(SentryEvent @event)
    {
        @event.SentryExceptions = @event.SentryExceptions
            .Where(e => e.Type != typeof(AggregateException).FullName).ToList();
        return @event;
    }
}

[mattjohnsonpint]

To summarize, we would like to add a client-side option to the SDK that will filter out aggregate exceptions, but would still keep all the inner exceptions.