[OSM-dev] [OSM-talk] donating read-only api-mirrors

Stefan de Konink stefan at konink.de
Fri Feb 6 17:11:35 GMT 2009


Tom Hughes wrote:
>>> The alternative is do much more complicated database queries which 
>>> are likely to be slower (impossibly so on mysql, but possibly 
>>> manageable with a different database).
>>
>> I still do not see how your database queries can be your main pain. 
>> That is just a one time bench and test action. Again MySQL is not 
>> /that/ bad. I really don't see a reason why first so much fuzz need to 
>> be generated to make things better for everyone.
> 
> MySQL cannot cope with joining the node and way tables so you have to 
> hold all the nodes in memory and then do a fetch of the ways which use 
> those nodes. I have tried various ways to construct a query which 
> fetches all the ways in a given bbox directly and have failed to find 
> anything that the optimiser can cope with.

For the different implementation I have created (GIS based, X/Y based) 
there were split out different methods. For me it is currently faster 
for a *huge* result set to bbox way_nds by joining them on the set that 
is bboxed by the bbox request. But if the set found is small enough the 
IN method is certainly more quick.

So you run your way request on a materialized IN (...) resultset?


>> [Sarcasm]Since the T at H folks that I think are /wasting/ resources on 
>> anything, /waste/ their human resources also on building a balanced 
>> infrastructure. I really don't mind to see them /waste/ their time on 
>> a quick main API.[/Sarcasm]
> 
> I think the T at H folks are completely bonkers, as do quite a few other 
> people that I've spoken to.

I can only totally agree. For some reason I cannot stop talking with 
myself everyday.

> Why would be kidding. You've been trolling here for quite long enough 
> for me to know what you like and (until today) I've been pretty much 
> ignoring any thread that you're posting in for at least a month now.

I'm happy you cannot be stopped by me in this thread :) But could never 
be sure these bonkers take over the main api ;)

> Thanks for proving my point. To quote your log "I don't think there's 
> any way to tell if an fcgi is hung" which is exactly what I said I had 
> said, that although one may be hung there is no way to tell which one.
> 
> Which is why I restarted all the daemons on that occasion.

The query was failing till 3am the next morning, at that time the task 
was done. To me it seems that you did not escalate the issue at all, nor 
that you gave feedback to an average user user that you claim you did 
not know. With one out of 8 failing, this was a visible issue.


Stefan




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