Consul Responses to Signals
SIGINT - Graceful leave by default.
SIGTERM - Non graceful leave by default.
Common kill signals and their impact on a running Consul process
| Signal name | Signal value | Effect |
|---|---|---|
| SIGHUP | 1 | Reloads Consul’s service configuration (some services like Checks, Services, Watches, HTTP Client Address and Log Levels) |
| SIGINT | 2 | Usually generated by a Ctrl-c, graceful shutdown by default |
| SIGKILL | 9 | Non-graceful shutdown by default |
| SIGTERM | 15 | Non-graceful shutdown by default |
We’ll explore combinations of signals and configurations and see how Consul behaves:
leave_on_terminate false & skip_leave_on_interrupt false.
- On SIGTERM signal known peers list will not be affected.
- On SIGINT(ctrl+c) signal known peers list will become null and the node will be deregistered from remaining nodes.
leave_on_terminate true & skip_leave_on_interrupt to false.
- On SIGTERM signal known peers list will become null and the node will be deregistered from remaining nodes.
- On SIGINT(ctrl+c) signal known peers list will become null and the node will be deregistered from remaining nodes.
leave_on_terminate true & skip_leave_on_interrupt to true.
- On SIGTERM signal known peers list will become null and the node will be deregistered from remaining nodes.
- On SIGINT(ctrl+c) signal known peers list will not be affected.
leave_on_terminate true & skip_leave_on_interrupt to true.
- On SIGTERM signal known peers list will not be affected.
- On SIGINT(ctrl+c) signal known peers list will not be affected.
Note that in case of a node failure (power failure or Consul kill signal) the known peers list will not affect.