DiagnosticsActivityFilter.cs

using System.Diagnostics;
using Hangfire.Client;
using Hangfire.Server;
using Hangfire.States;
using Hangfire.Storage;

namespace ActivitiesSupport
{
    public sealed class DiagnosticsActivityFilter : IClientFilter, IServerFilter, IApplyStateFilter
    {
        private const string ActivityItemsKeyName = "Diagnostics.Activity";

        private const string ParentIdParameterName = "My.Activity.ParentId";

        private readonly ActivitySource _activitySource;

        public DiagnosticsActivityFilter(ActivitySource activitySource)
        {
            _activitySource = activitySource ?? throw new ArgumentNullException(nameof(activitySource));
        }

        public void OnCreating(CreatingContext context)
        {
            using var parentActivity = _activitySource.StartActivity(
                $"background job '{context.Job.Type.Name}.{context.Job.Method.Name}'");

            parentActivity?.SetTag("job.type", context.Job.Type.FullName);
            parentActivity?.SetTag("job.method", context.Job.Method.Name);
            parentActivity?.SetTag("job.state", context.InitialState.Name);
            parentActivity?.SetTag("job.storage", context.Storage.ToString());

            if (parentActivity?.Id != null)
            {
                context.SetJobParameter(ParentIdParameterName, parentActivity.Id);
            }

            var activity = _activitySource.StartActivity(
                $"create job '{context.Job.Type.Name}.{context.Job.Method.Name}'",
                ActivityKind.Producer);

            context.Items[ActivityItemsKeyName] = activity;
        }

        public void OnCreated(CreatedContext context)
        {
            if (context.Items.TryGetValue(ActivityItemsKeyName, out var item) &&
                item is Activity activity)
            {
                if (context.Exception == null)
                {
                    activity.SetStatus(ActivityStatusCode.Ok, "Created");
                    activity.SetTag("job.id", context.BackgroundJob.Id);
                    activity.SetTag("job.created", context.BackgroundJob.CreatedAt.ToString("O"));
                }
                else
                {
                    activity.SetStatus(ActivityStatusCode.Error, "Exception");
                    activity.SetTag("exception.type", context.Exception.GetType().FullName);
                    activity.SetTag("exception.message", context.Exception.Message);
                    activity.SetTag("exception.stacktrace", context.Exception.ToString());
                }

                activity.Dispose();
            }
        }

        public void OnPerforming(PerformingContext context)
        {
            var parentId = context.GetJobParameter<string>(ParentIdParameterName);
            ActivityContext.TryParse(parentId, null, isRemote: true, out var parentCtx);

            var activity = _activitySource.StartActivity(
                $"perform job '{context.BackgroundJob.Job.Type.Name}.{context.BackgroundJob.Job.Method.Name}'",
                ActivityKind.Consumer,
                parentCtx);

            context.Items[ActivityItemsKeyName] = activity;
        }

        public void OnPerformed(PerformedContext context)
        {
            if (context.Items.TryGetValue(ActivityItemsKeyName, out var item) && item is Activity activity)
            {
                if (context.Exception == null)
                {
                    activity.SetStatus(ActivityStatusCode.Ok, "Performed");
                }
                else
                {
                    activity.SetStatus(ActivityStatusCode.Error, "Exception");
                    activity.SetTag("exception.type", context.Exception.GetType().FullName);
                    activity.SetTag("exception.message", context.Exception.Message);
                    activity.SetTag("exception.stacktrace", context.Exception.ToString());
                }

                activity.Dispose();
            }
        }

        public void OnStateApplied(ApplyStateContext context, IWriteOnlyTransaction transaction)
        {
            var parentId = context.GetJobParameter<string>(ParentIdParameterName);
            ActivityContext.TryParse(parentId, null, isRemote: true, out var parentCtx);

            using var activity = _activitySource.StartActivity(
                $"state change to '{context.NewState.Name}'",
                ActivityKind.Consumer,
                parentCtx);

            activity?.SetTag("state.old", context.OldStateName);
            activity?.SetTag("state.new", context.NewState.Name);
            activity?.SetTag("state.reason", context.NewState.Reason);
        }

        public void OnStateUnapplied(ApplyStateContext context, IWriteOnlyTransaction transaction)
        {
        }
    }
}