Re: [Maposmatic-dev] Database update becoming critical

[Maxime Petazzoni]

* David Decotigny <address@hidden> [2010-06-08 09:08:51]:

> It would be very interesting to have some benchmarks about this. At
> first I was dubitative about that claim, but on second thoughts, maybe
> it's right (startup overhead higher, but working sets smaller on the
> other hand => scan/search/sort overheads perhaps smaller). The only
> closely-related benchmark I'm aware of is
> http://lists.openstreetmap.org/pipermail/talk-fr/2010-May/021293.html
> (thanks, Thomas), do you know of any other tests with osmosis in the loop ?

So I guess the bottomline of all this is that switching to SSD storage
would solve the problem. Switching to minutely diffs would be a plus,
reducing the latency between new data being imported in OSM and this
data being available for render on MapOSMatic.

> To test this... Is there a "COW" feature for pgsql which would allow us
> to run a few tests with the prod DB, without altering the data delivered
> to ocitysmap ? If not, I'm afraid we'd have to test on another machine.

I'll try to import the planet database on my machine and test the
minutely diffs (quad core, 4gb ram, standard 7200rpm SATA drives).

- Maxime
-- 
Maxime Petazzoni <http://www.bulix.org>
 ``One by one, the penguins took away my sanity.''
Linux kernel and software developer at MontaVista Software

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