Why cannot the same path for cache be used several times?

[B.R.]

On Wed, Aug 6, 2014 at 8:47 AM, itpp2012 <nginx-forum at nginx.us> wrote:

> keys_zone is memory, the other a 'file' path, I could imagine a 'cachehash'
> used could overwrite the other.
>

​I thought of that​, but learning how variables are resolved at request
time, and knowing that configuration is parsed on HUP signal, I though
nginx would handle cache requests from different servers/locations the same
way it is dealing with them when they are coming from the same server.

I have not digged into the code, and I do not know if there is such thing
sa a 'cache manager' which would centralize cache management and respond to
cache events.

keys_zone are normally enough to avoid overwriting cache entries from other
zones.
Failing to do so, it would mean several keys_zone being used in the same
cache are not isolated and can lead to collision... that would be
catastrophic...
>From the assumption that keys_zone are collision-free, it would seem
reasonable to share the same cache file over several calls.

IMHO, the only thing that shall fail is the use of the same keys_zone on
the same file more than once.
Does not that sound reasonable?
​---
*B. R.*
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