Re: (ITS#5178) [feature request] pcache stats & monitoring

[masarati@aero.polimi.it]

> This is a feature request for stats and monitoring capabilities for
> pcache;
> basically:
>
> - the number of cached queries

The number of cachedQueryURL values

> - the number of cached entries

not available; maybe cachedQueryURL could carry a x-nentries=<num> extension

> - possibly, a list of cached queries in cachedQueryURL form

ditto

> - how many times each cached query was used instead of re-running the
> request
> - the ratio answerable / cacheable for each cacheable query
> - some global figure like the average response time (send searchResult
> time -
> start caching time) for each query, and the overall average.

None of the above is available.  The first one is interesting, but it
would require query information to survive its life, and match by
base/scope/filter rather than by queryUUID.

> Adding per-query info could be done by either extending the cachedQueryURL
> format or by adding a child entry for each cached query (like connections
> and
> other dynamic info).

This second option does not seem to be viable, although interesting.  I
fear too much overhead.

It's not clear yet how all of this stuff will need to cooperate with the
new TTR (and bind caching, when available).

p.