duplicate header error

[PoteRii]

Hello, we are getting following exception: An item with the same key has already been added. Key: cap-msg-group

at System.Collections.Generic.Dictionary2.TryInsert(TKey key, TValue value, InsertionBehavior behavior) at DotNetCore.CAP.Kafka.KafkaConsumerClient.Consume(ConsumeResult2 consumerResult)
at DotNetCore.CAP.Kafka.KafkaConsumerClient.Listening(TimeSpan timeout, CancellationToken cancellationToken)
at DotNetCore.CAP.Internal.ConsumerRegister.<>c__DisplayClass21_1.b__2()

This causes consumer to crash, decreases members of kafka consumer and thus increases lag (messages behind). We are not modifying headers and I could not find a message in DB with duplicate cap-msg-group header

any ideas for the cause?

[PoteRii]

turn out one of our provider produced an invalid message, which already contained cap-msg-group header. Can we move CustomerHeadersBuilder on top of other logic so such cases can be handled by it?

[yang-xiaodong]

Each has its own benefits, and placing them on top offers the possibility of rewriting Group.

Whether or not to place the headers.Add(Headers.Group, _groupId) to headers[Headers.Group] =_groupId looks good?

[PoteRii]

yes, that is also an option, since other implementations (e.g. Redis) use that approach as well

[yang-xiaodong]

yes, that is also an option, since other implementations (e.g. Redis) use that approach as well

Would you want to make a PR？

[PoteRii]

sure

[yang-xiaodong]

Fixed in v8.3.2