[squid-users] AUFS vs. DISKS

[Amos Jeffries]

On 24/09/2015 12:48 a.m., FredT wrote:
> Fred,
> We now have the 3.5.8 deployed with our clients, not yet switched to the
> 3.5.9...
> "strange" messages are not a problem because i suspect it's generated by the
> cache_swap_low/high, cleaning old objects.
> I suppose the Squid cleans old objects but another squid process does not
> take care this cleaning and see the (deleted) object does not exist anymore
> so it alerts there is something wrong...
> Personaly i do not take care these warning messages from the cache.log as
> squid is smart enough to manage missing objects.

If you want to achieve highest performance it is best to resolve that
process collision issue. The wrongly indexed entries will be causing
others to get expired earlier and maybe reduce HIT rate on them.

The (rather large amount of) extra work Squid is doing to cope with the
missing objects is also sucking away CPU and disk I/O cyces that would
be better used serving traffic.

So its not a big issue generally, but for high performance it can be an
extra latency issue.

Amos