Dashboard does not show exception for retries

[DavidLievrouw]

I have noticed an inconsistency between Hangfire.Mongo and other storages, like in-memory, and Redis (Hangfire.Pro):
When a job is retried, the encountered exception is not shown in the dashboard, when using Hangfire.Mongo.

When using any of the other storages I tested, the exceptions are shown on every retry.

When I use the ASP.NET Core sample, and make a job fail, I get this.

Any of the others do this (notice the Failed-state with exception information):

I traced the issue down to the MongoWriteOnlyTransaction class. It only saves the latest StateHistory item to the database, instead of all the ones that were encountered, during handling of all the configured state filters.

I don't know if this behavior is the desired behavior. It might be for performance reasons. But in any case, to change it, I did the following:

MongoJobUpdates.cs

/// <summary>
/// Updates for a specific job
/// </summary>
public class MongoJobUpdates
{
    /// <summary>
    /// Set updates
    /// </summary>
    public BsonDocument Set { get; } = new();

    /// <summary>
    /// Push updates
    /// </summary>
    public List<BsonDocument> Pushes { get; } = new();

    /// <summary>
    /// Creates a UpdateOneModel with a filter for the given job id
    /// </summary>
    /// <param name="jobId"></param>
    /// <returns></returns>
    public UpdateOneModel<BsonDocument> CreateUpdateModel(string jobId)
    {
        var filter = new BsonDocument("_id", ObjectId.Parse(jobId));
        var update = new BsonDocument();
        if (Set.Any())
        {
            update["$set"] = Set;
        }

        if (Pushes.Any())
        {
            var pushByElement = Pushes
                .SelectMany(p => p)
                .GroupBy(elem => elem.Name)
                .Select(g => new BsonElement(g.Key, new BsonDocument("$each", new BsonArray(g.Select(e => e.Value)))));

            update["$push"] = new BsonDocument(pushByElement
                .ToDictionary(p => p.Name, p => p.Value));
        }


        var updateModel = new UpdateOneModel<BsonDocument>(filter, update);
        return updateModel;
    }
}

MongoWriteOnlyTransaction.cs

 public override void SetJobState(string jobId, IState state)
        {
            var stateDto = new StateDto
            {
                Name = state.Name,
                Reason = state.Reason,
                CreatedAt = DateTime.UtcNow,
                Data = state.SerializeData()
            }.Serialize();

            var updates = GetOrAddJobUpdates(jobId);
            updates.Set[nameof(JobDto.StateName)] = state.Name;
            updates.Pushes.Add(new BsonDocument(new Dictionary<string, object>
            {
                { nameof(JobDto.StateHistory), stateDto }
            }));
        }

        public override void AddJobState(string jobId, IState state)
        {
            var stateDto = new StateDto
            {
                Name = state.Name,
                Reason = state.Reason,
                CreatedAt = DateTime.UtcNow,
                Data = state.SerializeData()
            }.Serialize();

            var updates = GetOrAddJobUpdates(jobId);
            updates.Pushes.Add(new BsonDocument(new Dictionary<string, object>
            {
                { nameof(JobDto.StateHistory), stateDto }
            }));
        }

Now the exceptions are shown for every retry.

Should I create a PR, or is the current behavior as intended?

Thanks for your efforts.

[gottscj]

@DavidLievrouw,

Thank you for the feedback! I can do the required updates if you like. Im also looking into an optimization another place in the MongoWriteOnlyTransaction anyways.

Thanks!

[gottscj]

@DavidLievrouw,

I added your changes. Please let me know if it works as you expect.

Thanks for the help!

[DavidLievrouw]

Perfect! Thank you.