On Thu, Jan 29, 2026 at 5:10 PM Fujii Masao <[email protected]> wrote: > > On Wed, Jan 28, 2026 at 10:02 PM Ahmed Et-tanany > <[email protected]> wrote: > > > > Yes, that's what I meant. > > Would something like max_logical_wal_senders also be needed for your purpose? > Otherwise, logical replication connections could exhaust max_wal_senders and > prevent physical replication connections from being established. >
I could be mistaken, but I haven’t found a way to start a logical replication stream without a replication slot. A replication connection and walsender can exist without a slot, for example: ./psql "host=localhost port=5432 user=user1 dbname=postgres replication=database" However, converting that connection to logical replication requires a slot from the max_logical_replication_slots pool. If that pool is exhausted, the connection cannot be converted — in which case, wouldn’t a single GUC suffice? I might be missing something — are you referring to a different scenario? One possibility is if max_wal_senders is lower than max_logical_replication_slots, which could exhaust WAL senders for logical connections, though that would mostly be a configuration issue. Isn't it? thanks Shveta
