On Wed, Jun 29, 2016 at 11:15 PM, Barak Korren <bkorren@redhat.com> wrote:
On 29 June 2016 at 21:45, Yaniv Kaul <ykaul@redhat.com> wrote:
> On Mon, Jun 27, 2016 at 9:45 AM, Barak Korren <bkorren@redhat.com> wrote:
>> >
>> >
>> > It means that packages will be fetched EVERY time from outside, which
>> > may be
>> > slow(er).
>> > Y.
>> >
>> We can (and mostly already have) setup simple caches to prevent that.
> How do you set up cache on a developer's laptop?
We may have been unclear in our intentions, we want to make the
pre-syncing optional not remove it completely. It does make sense on
the laptop (sometimes), but not so much in the CI env.

> The repo directory does not need to be cleaned every time.

This is an assumption that may break if we end up having any corrupt
or failing packages in the cache. It also make it hard to "go back in
time" if we want to test without some update.
(Cleaning corrupt caches an re-running is easy in a local setting, in
CI you end up dealing with angry devs getting false '-1's)

True, and we don't want that. Developers have to trust the CI system.
This is an important point.

> It can also be
> resync'ed from a central repo - which still going to be faster than any
> other fetching.
> (hopefully sync'ed into the slave /dev/shm btw).

It could be faster, but could also be slower if you end up fetching
more then you have to. (if engine setup fails on missing dependency,
you just spent needless time fetching VDSM dpes)
Also fetching by itself may not be the bottleneck in all cases, it is
surely slow when fetching from PHX to TLV, but when fetching from the
Squid proxy's RAM inside PHX it can actually end up being faster then
copying from the local disk.

I always fetch and store on /dev/shm/repostore
It's faster than anything else.

I did copy its content once to the disk, so when the host reboots, it rsync's this to /dev/shm/repostore , then tests begin.
That perhaps is indeed not very needed in CI.

>> The existing solution looks more like premature optimization gone badly
>> IMO.
> Try to run ovirt-system-tests, clean the repo and re-run - it's 20-30
> minutes at least longer - which is far more than what it takes to run the
> whole test suite.

I wonder how many of those minutes are spend on fetching things we
actually need, and how much is spent on overhead. I suspect that
without a local cache, the test run will be longer, but not as long as
the pre-fetching+tests takes currently. More importantly, this may
allow the CI to fail faster. I think we should at least test that.

> I completely agree the manual maintenance is an annoyance, wish we had
> something in between.

Maybe we can take a middle ground, pre-fetch, but also enable external
repos in CI (perhaps with some way to log and find out what was not

This is what the code is supposed to do, I suspect. reposync syncs between what you already have and what you fetch, no?

Barak Korren