max_concurrent_io

Available since NATS Server 2.15

Hot Reloadable

Only reloadable while JetStream is being disabled in the same reload (the whole jetstream block removed or enabled: false set). Any other change while JetStream stays enabled fails the reload.

Maximum number of disk I/O operations the server allows in flight at once, across all streams and consumers. Must be between 4 and 8192. Lower it to reduce contention for the underlying disk on a server with many assets; raise it on fast storage to allow more parallel I/O.

Types

Type	Description	Choices
integer	-	-