3.8 Service Removal

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When a definition disappears from Machine\System\Services\, peinit learns of it through the ordinary change-notification path. What happens next depends on whether anything is running.

3.8.1 Not running #

An entry in Inactive, Failed, Completed, Skipped or Abandoned is discarded immediately. There is no process to consider.

3.8.2 Running #

An entry in Active, Starting, Reloading, Backoff or Stopping is not killed. The running process is a job, and a job's lifecycle is independent of the definition that produced it — removing a definition stops future management, it does not terminate work in progress.

peinit marks the entry definition-removed and keeps the cached definition, solely to go on supervising the instance it already has. When that instance exits it is not restarted — RestartPolicy is moot, because there is nothing left to restart from — and peinit then discards the entry.

While an entry is definition-removed:

• it keeps satisfying its dependents for as long as the instance is alive, because it is still running;
• stop is accepted, so an administrator can drain it cleanly, using the cached StopTimeout;
• start, restart and reload are rejected with UNKNOWN_SERVICE — there is no definition to work from;
• status reports the current runtime state with definition_removed set, so the draining instance is visible rather than silent.

definition-removed is a flag on the existing runtime state, not a state of its own. The state machine (§6.1) and the command × state matrix (§10.3) are unchanged by it.

Once the instance exits or is stopped, the entry — including anything in its fd store (§10.6) — is discarded. A dependent that Requires the removed service keeps being satisfied while the instance runs; after the entry is discarded, the dependent's next start sees an unresolved dependency and takes the ordinary validation path.

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