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| author | Michael Olbrich <m.olbrich@pengutronix.de> | 2012-02-01 17:17:12 +0100 |
|---|---|---|
| committer | Lennart Poettering <lennart@poettering.net> | 2012-02-01 19:29:19 +0100 |
| commit | a6927d7ffc18c51fbb9940f5f1e89f5c7695ed63 (patch) | |
| tree | a56630fa33002013683a69126a2caec16ef31b6c /src/systemd | |
| parent | c4aa65e7147dc742886edf25593e10466b02fc3a (diff) | |
service: add watchdog timestamp
This patch adds WatchdogTimestamp[Monotonic] to the systemd service
D-Bus API. The timestamp is updated to the current time when the
service calls 'sd_nofity("WATCHDOG=1\n")'.
Using a timestamp instead of an 'alive' flag has two advantages:
1. No timeout is needed to define when a service is no longer alive.
This simplifies both configuration (no timeout value) and
implementation (no timeout event).
2. It is more robust. A 'dead' service might not be detected should
systemd 'forget' to reset an 'alive' flag. It is much less likely
to get a valid new timestamp if a service died.
Diffstat (limited to 'src/systemd')
| -rw-r--r-- | src/systemd/sd-daemon.h | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/src/systemd/sd-daemon.h b/src/systemd/sd-daemon.h index eb2a60651..7b664bf42 100644 --- a/src/systemd/sd-daemon.h +++ b/src/systemd/sd-daemon.h @@ -217,6 +217,11 @@ int sd_is_mq(int fd, const char *path); MAINPID=... The main pid of a daemon, in case systemd did not fork off the process itself. Example: "MAINPID=4711" + WATCHDOG=1 Tells systemd to update the watchdog timestamp. + Services using this feature should do this in + regular intervals. A watchdog framework can use the + timestamps to detect failed services. + Daemons can choose to send additional variables. However, it is recommended to prefix variable names not listed above with X_. |