sysstat blocks fcron running cron.hourly

[Clos3y]

Is this a new report?

Yes

System Info

Void 6.6.22_1 x86_64 AuthenticAMD notuptodate rrrmFFFF

Package(s) Affected

sysstat-12.7.2_1, fcron-3.3.1_2

Does a report exist for this bug with the project's home (upstream) and/or another distro?

No, not that I can see

Expected behaviour

fcron runs all scripts in /etc/cron.hourly

Actual behaviour

fcron runs all scripts alphabetically up to sysstat. This process does not terminate, locking fcron and preventing the execution of files starting with letters after 's' in /etc/cron.hourly.

Steps to reproduce

0. Install sysstat, fcron, and setup the fcron service and systab crontab.
1. Create a script in /etc/cron.hourly.
2. If it comes before 'sysstat' alphabetically, it will be executed when the systab is set to run hourly. If it comes after, it will not execute until around fifty minutes after due to sysstat locking.

[classabbyamp]

probably caused by sysstat/sysstat@e659232, where an assumption is probably made that the cron daemon runs things in cron.hourly asynchronously

[Clos3y]

Hmm, adding & back in (and running # fcrontab -z -u systab followed by a reboot) doesn't fix the issue for me: it's still locked. fcron doesn't seem to care if you use &, it'll still lock. For example, I just tested

while true; do sleep 5; done &

in a test file in /etc/cron.monthly, reloaded the system crontab, and then forced /etc/cron.monthly to run with fcrondyn. fcron is still executing and is locked:

2024-03-27T00:20:08.44950 cron.notice: Mar 27 00:20:08 fcron[3843]: Job '/usr/bin/run-parts /etc/cron.monthly' started for user systab (pid 3844)
2024-03-27T00:20:46.30541 cron.warn: Mar 27 00:20:46 fcron[1022]:     process already running: systab's '/usr/bin/run-parts /etc/cron.monthly'

Perhaps this is an fcron issue specifically?

[classabbyamp]

then yeah it's probably fcron. might be interesting to check how another cron daemon reacts to this

[Clos3y]

I've tested with cronie: if you add the & to the script, cronie has no problem and will execute the rest. But in its current state without the &, the script will lock cronie too.

So I think a solution might be to patch /etc/cron.hourly/sysstat to reinclude the & and just accept that fcron misbehaves, but I appreciate the Void ethos is to have upstream fix these things.

[leahneukirchen]

Surely cronie runs all jobs in parallel?

[leahneukirchen]

But perhaps sysstat should use a /etc/cron.d file, as run-parts from 0hourly will run in sequence (by design).

So sysstat shouldn't be run from cron.hourly.

[Clos3y]

Surely cronie runs all jobs in parallel?

Seemingly not. cronie and fcron call run-parts which, if you execute it on /etc/cron.hourly, will take 50 mins to finish due to sysstat's current form.

But perhaps sysstat should use a /etc/cron.d file, as run-parts from 0hourly will run in sequence (by design).

So sysstat shouldn't be run from cron.hourly.

Yeah that sounds sensible, so just change these to etc/cron.d?

void-packages/srcpkgs/sysstat/template

Lines 25 to 26 in fc3f3c3

	vmkdir etc/cron.daily
	vmkdir etc/cron.hourly

[leahneukirchen]

I'm at it, let me test it locally.