A systemd unit with a restart limit that finally fired

A burst limit configured in 2023 as a precaution, which took three years to be needed.

[Unit]
StartLimitIntervalSec=300
StartLimitBurst=5

[Service]
Restart=always
RestartSec=5

# 04:12, and the unit entered failed after five
# restarts in forty seconds. which is the correct
# behaviour and is the first time it has happened.

Without the burst limit the worker would have restarted every five seconds indefinitely, reporting active, which is the failure this configuration exists to convert into something visible. The unit entering failed is what the alert keys on — a crash loop with Restart=always and no limit is invisible to every check that asks whether the service is running.