Re: (ITS#8724) slapo-pcache truncates remote results

[adam@brainfood.com]

Cool.  I've looked at pcache.c, and realized I'm a noob with this code.

Basically, my thoughts, is that pcache should ignore the incoming
search request, and recreate it's own with it's own options, always
asking for paging.  Then page through all the results from the
backend, then store the full set in the backing store.

While that is going on, the cache entry should be marked with a bit
flag saying that it's in the process of being built, but otherwise can
still store the entries fetched thus far.

Meanwhile, the frontend request can begin to return results from this
partially resolved backend entry stored in the cache, utilizing
whatever pagination value(and or offset/limit) has been requested.

Of course, that's just the high-level description, not even really
pseudo-code ready.

As an aside, and this s/b a separate bug, if an error occurs from the
backend this does *not* get cached.  Aka, during this investigation,
my backend is returning 2000 entries, err=4.  This takes 7s each
time(I'm in Dallas, while the backend is in California, and I'm
communicating over a tunnel).  It's not cached, so the request is
passed through each time. I've configured the templates correctly, and
the debug shows that the request is CACHEABLE.



On Wed, Sep 6, 2017 at 6:22 PM, Quanah Gibson-Mount <quanah@symas.com> wrote:
> --On Wednesday, September 06, 2017 7:06 PM -0500 Adam Heath
> <adam@brainfood.com> wrote:
>
>
>> Well, then since you are confirming the bug, I would say this ticket
>> should *not* be closed.
>
>
> I already reopened it. ;)
>
>> I might just have to patch this to make it work.
>
>
> Make sure you follow the contribution guidelines:
>
> <https://www.openldap.org/devel/contributing.html>
>
> Thanks,
>
> Quanah
>
> --
>
> Quanah Gibson-Mount
> Product Architect
> Symas Corporation
> Packaged, certified, and supported LDAP solutions powered by OpenLDAP:
> <http://www.symas.com>
>