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Lessons from a year of Postgres CDC in production

74 points by saisrirampur

by ahachete

3 subcomments

> "As part of the acquisition, we made an important decision: not only to keep PeerDB open source"
> "Here goes the Open Source reference to our validation logic."
> "PeerDB Open Source Repository"
I hate to be that guy, but PeerDB seems to be governed by the Elastic License [1] which makes it NOT open source.
The difference is not small, but significant for many. For one, it won't get integrated into other OSS projects.
In my particular case, we have integrated Debezium Embedded into StackGres, as a high level object (CRD) named SGStream [2]. It allows Postgres logical replication from Postgres and exports to another Postgres and/or CloudEvents. No Kafka required. We'd love to consider other alternatives like PeerDB, but not being OSS is a red line we can't cross (having said that, we're really happy with Debezium in general, but having competition and alternatives it's always great).
[1]: https://github.com/PeerDB-io/peerdb/blob/main/LICENSE.md
[2]: https://stackgres.io/doc/latest/reference/crd/sgstream/#sgst...
[edit: formatting]

by MuffinFlavored

1 subcomments

> We discovered that on reconnect, Postgres would start reading the replication slot’s WAL from the restart_lsn—effectively the beginning—rather than from the last processed position. For workloads with long-running, large, or interleaved transactions, this meant unnecessarily re-reading large portions of WAL and drastically impacting replication lag.
I wonder if that's intended by Postgres? Doesn't seem logical at first glance.