Max concurrent WAL sender processes (standbys + base backups).
At a glance
| Property | Value |
|---|---|
| Parameter | max_wal_senders |
| Category | Replication |
| Default | 10 |
| Value type | boolean / enum / numeric |
| Change scope | Restart required |
What it does
Maximum number of simultaneous connections from streaming replicas and base-backup clients.
How to apply a change
Requires a full server restart (postmaster context). Set it in postgresql.conf and restart PostgreSQL.
Inspect the current value and source with SHOW max_wal_senders; or SELECT name, setting, unit, context, source FROM pg_settings WHERE name = 'max_wal_senders';.
Tuning guidance
Allow one per standby plus headroom for concurrent pg_basebackup jobs. Counts against connection-related shared memory.