[HN Gopher] Husky, Datadog's Third-Generation Event Store
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Husky, Datadog's Third-Generation Event Store
Author : louis-paul
Score : 5 points
Date : 2022-05-17 22:04 UTC (57 minutes ago)
(HTM) web link (www.datadoghq.com)
(TXT) w3m dump (www.datadoghq.com)
| rektide wrote:
| Lovely read. Condensing some, there's three node types in the
| system, writers, compactors, and readers.
|
| > _Writers read from Kafka, (briefly) buffer events in memory,
| upload events to blob storage in our custom file format, and then
| commit the presence of these new files to our metadata store....
| Compactors scan the metadata store for small files generated by
| the Writers and previous compactions, and compact them into
| larger files.... The Reader (leaf) nodes run queries over
| individual files in blob storage and return partial aggregates,
| which are re-aggregated by the distributed query engine._
|
| And then the meta-data supporting the system:
|
| > _Husky 's metadata store has multiple responsibilities, but its
| most important one is to serve as the strongly consistent source
| of truth for the set of files currently visible to each customer.
| We'll delve into the details of our metadata store more in future
| blog posts, but it is a thin abstraction around FoundationDB,
| which we selected because it was one of the few open source OLTP
| database systems that met our requirements_
|
| There's some nice scalability/isolation benefits in this all.
| Having reader nodes reading from network storage has created a
| lot of flexibility & ability to shift work around on demand.
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(page generated 2022-05-17 23:02 UTC)