BUG/MINOR: server: don't use date when restoring last_change from state file
When restoring from a state file: the server "Status" reports weird values on
the html stats page:
"5s UP" becomes -> "? UP" after the restore
This is due to a bug in srv_state_srv_update(): when restoring the states
from a state file, we rely on date.tv_sec to compute the process-relative
server last_change timestamp.
This is wrong because everywhere else we use now.tv_sec when dealing
with last_change, for instance in srv_update_status().
date (which is Wall clock time) deviates from now (monotonic time) in the
long run.
They should not be mixed, and given that last_change is an internal time value,
we should rely on now.tv_sec instead.
last_change export through "show servers state" cli is safe since we export
a delta and not the raw time value in dump_servers_state():
srv_time_since_last_change = now.tv_sec - srv->last_change
--
While this bug affects all stable versions, it was revealed in 2.8 thanks
to 28360dc ("MEDIUM: clock: force internal time to wrap early after boot")
This is due to the fact that "now" immediately deviates from "date",
whereas in the past they had the same value when starting.
Thus prior to 2.8 the bug is trickier since it could take some time for
date and now to deviate sufficiently for the issue to arise, and instead
of reporting absurd values that are easy to spot it could just result in
last_change becoming inconsistent over time.
As such, the fix should be backported to all stable versions.
[for 2.2 the patch needs to be applied manually since
srv_state_srv_update() was named srv_update_state() and can be found in
server.c instead of server_state.c]
(cherry picked from commit 9c21ff0208a5d87086e2ddb4fc6f2d981b75555b)
Signed-off-by: Christopher Faulet <cfaulet@haproxy.com>
(cherry picked from commit 48af6ff9d3209324fbced766aa7ff1aa72a8e37f)
Signed-off-by: Christopher Faulet <cfaulet@haproxy.com>
(cherry picked from commit fb5b4ac792078255af5231a5a854312bf1b87fe0)
Signed-off-by: Christopher Faulet <cfaulet@haproxy.com>
1 file changed