Monit exec without alert

[Callum Macdonald]

I'm using monit to monitor our tmpfs filesystems which are used for
caching purposes. I've written a script which deletes the oldest 10% of
files, according to their atime.

I've configured monit to run that script with exec when the filesystem
usage reaches 90%, like this:

check device cachefs with path /foo/cache
        alert address@hidden but not on { exec }
        if space usage > 90% then exec "/bar/reduce_cache.sh" as uid
apache and gid apache
        if inode usage > 80% then exec "/bar/reduce_cache.sh" as uid
apache and gid apache
        if space usage > 97% for 5 cycles then alert
        if inode usage > 90% for 5 cycles then alert

This node is running monit 4.10.1.

Currently I get emails like this:
* Resource limit matched Service cachefs
* Resource limit passed Service cachefs

I get two emails every time, one when the exec is run, then a second
when the test recovers. I want to disable both of those emails, for this
filesystem check only.

I *do* want to get an email if the script fails and filesystem usage
hits 97% or more.

Can I do something like:
        if space usage > 90% then exec "/foo/reduce_cache.sh" not alert

I've read the docs but can't figure out the syntax. As I read the
documentation, alerts can be enabled for the whole filesystem check or
not at all, but not per test. Is that correct?

Do I need to create two different checks? Is there any danger in having
two monit checks monitoring the same filesystem?

Alternatively, is using monit's exec the "wrong" approach to control
cache usage? I figured it was simpler and possibly more reliable than a
cron script which parses the output of `df` and calls the script when
required.

Thanks in advance for any input.

Love & joy - Callum.

==
Callum Macdonald

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