<![CDATA[PostgreSQL addon: optional logical replication for apps that need it]]>Some apps now need PostgreSQL logical replication. The one I've hit is wger: since version 2.0, its mobile app requires PowerSync, which reads changes from the wger database through a logical replication slot. PowerSync, ElectricSQL, Supabase Realtime, Zero and Debezium all work this way.

The addon currently can't support this. The server runs with wal_level=replica, and app roles don't have the REPLICATION attribute. Neither can be changed from inside a package, so the only option is to bundle a separate PostgreSQL in the app and give up the addon's managed backups and upgrades.

Would you consider an opt-in addon option, something like "postgresql": { "logicalReplication": true }? It would need to:

  • run the server with wal_level=logical (the only cost to other apps is somewhat more write-ahead log (WAL) volume)
  • grant REPLICATION to the role of each app that asks for it
  • set max_slot_wal_keep_size, so an abandoned slot can't fill the shared disk
  • drop the app's replication slots on uninstall and before a restore

With that, packages like wger could stay on the addon instead of each shipping its own database.

]]>https://forum.cloudron.io/topic/15996/postgresql-addon-optional-logical-replication-for-apps-that-need-itRSS for NodeSat, 26 Sep 2026 09:23:10 GMTTue, 22 Sep 2026 10:06:20 GMT60<![CDATA[Reply to PostgreSQL addon: optional logical replication for apps that need it on Wed, 23 Sep 2026 13:04:57 GMT]]>

I presume you noticed, but, 18 is not 19 🙂

that's sadly true. 19 will be released... soon this autumn (also, I haven't tested that change yet, only have that from the docs)

]]>https://forum.cloudron.io/post/129908https://forum.cloudron.io/post/129908Wed, 23 Sep 2026 13:04:57 GMT<![CDATA[Reply to PostgreSQL addon: optional logical replication for apps that need it on Wed, 23 Sep 2026 12:59:09 GMT]]>

@girish said:

postgres 18

I presume you noticed, but, 18 is not 19 🙂

]]>https://forum.cloudron.io/post/129907https://forum.cloudron.io/post/129907Wed, 23 Sep 2026 12:59:09 GMT<![CDATA[Reply to PostgreSQL addon: optional logical replication for apps that need it on Wed, 23 Sep 2026 12:58:05 GMT]]>Oh thanks for that @jdaviescoates , i had missed that note from @rolig . So, we will roll out postgres 18 next week as part of 10.1. I guess we might just wait it out instead of adding this feature flag.

]]>https://forum.cloudron.io/post/129906https://forum.cloudron.io/post/129906Wed, 23 Sep 2026 12:58:05 GMT<![CDATA[Reply to PostgreSQL addon: optional logical replication for apps that need it on Wed, 23 Sep 2026 12:55:12 GMT]]>@girish see also:

@roliG said:

FYI, it seems postgres 19 won't need the explicit "wal_level = replica", as it will automatically set it if there's a replication

]]>https://forum.cloudron.io/post/129905https://forum.cloudron.io/post/129905Wed, 23 Sep 2026 12:55:12 GMT<![CDATA[Reply to PostgreSQL addon: optional logical replication for apps that need it on Wed, 23 Sep 2026 12:32:17 GMT]]>@loudlemur I will have to read up on this, to see what this is

]]>https://forum.cloudron.io/post/129903https://forum.cloudron.io/post/129903Wed, 23 Sep 2026 12:32:17 GMT