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mongodbpersistenceakka.net

Akka.net | MongoDB only loads one event

I'm currently working with akka on a new project. But now I'm stuck with a problem.

I added a mongo db to my project and set the journal and snapshotstore. I can persist events and the events will be stored in the database. That works great.

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But when I restart the application and the actor starts to recovering the events, the actor only restore the first event. It seems that the Recovery upper SequenceNr Limit is set to 1 but I've already checked that. After the recovery of this first event the actor received the message RecoveryCompleted and the recovery process is finished.

The recovery methods

private void recovers()
{
    Recover<TenantCreated>(evt =>
    {
        applyEvent(evt);
        Context.System.EventStream.Publish(evt);
    
    });

    Recover<TenantDeleted>(evt =>
    {
        applyEvent(evt);
        Context.System.EventStream.Publish(evt);
    });

    Recover<SnapshotOffer>(snapshot =>
    {
        this.state = (TenantCollection)snapshot.Snapshot;
    });

    Recover<RecoveryCompleted>(msg =>
    {
    });
}

One method that persists an event

Command<CreateTenant>(command =>
{
    Persist(new TenantCreated(command.Id, command.UserId, command.Name, new Guid(command.Id).ToString("N")), evt =>
    {
        var newTenant = applyEvent(evt);

        newTenant.Tell(command);

        persistAndPublishEvent(evt);
    });
});

My akka configuration. The connectionString will be loaded with a fallback. With this I can set the connectionString as an environment variable.

persistence {
    journal {
        plugin = "akka.persistence.journal.mongodb"
        mongodb {
            class = "Akka.Persistence.MongoDb.Journal.MongoDbJournal, Akka.Persistence.MongoDb"
            collection = "EventJournal"
            plugin-dispatcher = "akka.actor.default-dispatcher"
        }
    }

    snapshot-store {
        plugin = "akka.persistence.snapshot-store.mongodb"
        mongodb {
            class = "Akka.Persistence.MongoDb.Snapshot.MongoDbSnapshotStore, Akka.Persistence.MongoDb"
            collection = "SnapshotStore"
            plugin-dispatcher = "akka.actor.default-dispatcher"
        }
    }
}

What is the problem?

Does anyone has the same problem?

Solution

  • Yep, looks like this is a bug after all - deleting the metadata table exposed it.

    It's because we don't apply indexes to the collections by default (and haven't ever, by the looks of it - which we missed because the configurations in our test suites are different:) https://github.com/akkadotnet/Akka.Persistence.MongoDB/blob/552a29eed4c839fe4f91fceeb70bb29eb17d1315/src/Akka.Persistence.MongoDb/reference.conf#L11

    So this was really helpful - turns out our large users never had this issue because they ran with auto-initialize=on in their configurations this entire time. You were affected by the defaults being different.

    https://github.com/akkadotnet/Akka.Persistence.MongoDB/releases/tag/1.4.21 - we released Akka.NET v1.4.21 which fixes this.