watchHeartbeatInterval

watchHeartbeatInterval is the interval at which the client asks the server to send a heartbeat on an idle Watch stream, so that a half-open stream is noticed and reconnected (watchIdleTimeoutMs, c69e6bda/#1472). It is a request, not a setting: the server clamps it to its own bounds and the client times a silent stream out at three times the interval the server actually settles on and advertises back on the init frame. A non-positive value asks for no heartbeats, which also leaves the stream without an idle timeout. The default value is 20000(ms).

Unlike channelHeartbeatInterval, which is how often the client sends a channel refresh to keep a channel session alive, this is how often the server writes to the client's own Watch stream.

Note: Options is a data class without @JvmOverloads, so adding this trailing parameter keeps Kotlin source compatibility but changes the generated constructor and copy signatures for Java callers.

Ported from JS client.ts's watchHeartbeatInterval option (c1a03877/#1483).