Hi,
Intermittently between approximately 16:00 and 21:00Z today (2nd
Jan), a host which runs one of BitFolk's caching DNS resolvers
(212.13.194.71) was overloaded, causing poor performance for many of
you.
The cause was recent changes in the data transfer monitoring
scripts as previously discussed and detailed in:
https://tools.bitfolk.com/redmine/issues/15
It seems that the more heavyweight method of estimating data
transfer is in some cases slow enough to still be running when the
next scheduled invocation of the script runs, causing both to run
slower, and the problem to spiral.
Since no hosts or critical services were actually reported down, we
weren't made aware of the issue as quickly as might have been
desired.
I have now made some modifications:
- It's now not possible for multiple copies of these scripts to run
at once.
- If system load is too high then the expensive checks will now be
skipped entirely.
There is also the fact that this host is simply doing too much - it
shouldn't be running these scripts in addition to being a resolver.
In the next few days I will be provisioning an additional resolver
and eventually this one will be retired.
Apologies for any disruption this may have caused for you.
Cheers,
Andy
--
http://bitfolk.com/ -- No-nonsense VPS hosting