Failing event deserialization test

[zbartos]

We've an issue with some particular serialized events and metadata.

The metadata attached as well as two serialized events so the test emulates real case... BtdbMissingMetadataException thrown for second event although it shouldn't.

[Bobris]

61 at beggining means type DiskInfoAdded. First field is List so next number is number of items + 1. Clearly 62 is totally wrong. So we have to find out how this was created in first place.

[zbartos]

So does it mean that event serialized bytes are wrong by itself (metadata independent)? It's very hard to find out how it was created because data were produced by three QA guys installation and I guess nobody knows what they really did... There was three-nodes cluster but another back-end services were running there too. Kafka request log was by default turned off. Despite of that we think that events and corresponding metadata should be produced info Kafka correctly even in case of more back-end services...

[Bobris]

Yes this is just corrupted no problem in metadata. Will try later to skip first 61 and start directly with 62.

[Bobris]

Hmm 62 is "type" of first field, the List<DbDriveInfo>. But that's wrong because List should be always written as inline. It does not look like corruption, there is probably some mistake, but we need to reproduce.

[Bobris]

It would be interesting to have all such events starting 61 and as second byte something else than 4.

[zbartos]

I've extracted required test data (all events starting 61 and as second byte something else than 4) from the Kafka topic and created pull request. Later I've seen in QA guys provided log files that another back-end services were older versions. But I don't know whether they directed them to this Kafka or another Kafka instance, mess in that... I guess it's possible that older back-end fed events into this Kafka topics, newer back-end started then..., perhaps could it cause the issue?