This article is aimed to explain when EC2 instances start, stop, and terminate.
When a workspace is launched, it is scheduled to run on a specific EC2 instance. This could mean launching a new EC2 instance of the given hardware tier or starting one that has been stopped (e.g. a machine that is set to sleep but not terminated). Domino defines these machines as Executors and they are members of a grouping called hardware tiers.
Once an Executor is used and no longer needed (i.e. idle), it will be subject to some lifecycle management by the Domino application:
- If no runs have been scheduled on a machine for 120 minutes (i.e. idle) then it will be stopped (i.e. set to sleep). The default for executorStopTimeout is 120 minutes but can be configured to a different number.
When the instance is stopped, the charges are only for the EBS volumes and there are no EC2 instance charges.
You can view how long an instance has been idle or stopped under the `Instance State` column on the Dispatcher page. For example, prod-exec-d-free-107 has been in the stopped state for approximately 13 hours.
- While in the stopped state, the Executor will be available to be woken up for a run if it is needed. This is preferred over immediately terminating the Executor as it is more efficient for the machine to go from Stopped to Running than launching a new one.
- After the executorTerminateTimeout has passed, the executor will be terminated. The default for this is 3 days. Once terminated, the machine no longer exists and there are no longer charges to AWS.