lock verifiedWritten by the Hub
Lock file
in the configuration this is a line
lock: /tmp/mailerq.pidFile holding the process id, used to keep two engines from running at once.
Values
- Values
file path- Default
/tmp/mailerq.pid · taken from the build- applying
restart required- where it can be set
in the config file · with a startup flag · as an environment variable
In detail
Kept in /tmp by default, which is the one detail worth changing: on a system that cleans /tmp, the lock can disappear under a running process. A second engine started afterwards would consume the same queue with the same identity — and the symptom, duplicate deliveries, would not obviously point back here.
What happens if you get it wrong
The lock file is removed while the engine runs.A second instance can start and consume the same queue, delivering some messages twice.inference · inference