Via a command-line parameter and/or server command.

May be used to stop TTL deletes if the system is under extreme load or during an outage/corruption investigation. A single global (or per-DB) setting would be easier than having to update or drop all TTL indexes.

By default, the TTLMonitor thread is enabled. To disable at startup:

--setParameter ttlMonitorEnabled=false

To disable at runtime:

db.adminCommand({setParameter:1, ttlMonitorEnabled:false})