start

Registers the application's subscriptions and joins every context's lease group: heartbeats, reconciles, and acquires its share of the partitions, starting their subscriptions. A start that fails stops what it started and throws.

With standby (the dual-run window of a migration's cut-over) the node starts serving reads only: it registers the subscriptions but joins no lease group, so no subscription handles anything, no parked entry is retried and no job or schedule runs, and its gateway refuses every command (FrameworkCodes.NODE_STANDBY). activate then joins the groups, at the cut-over: a subscription that starts at the end of its stream starts where the stream ends then, not where it ended when the node booted.

Starts the node as start does, on standby when standby says so (see start).