Though it is true that children repos are consulted in order, this is a not a 
contract.
Why don't we have mirroring support for things served from archive?
Also rather than changing the repos, why can't we have http-level redirect for 
these URLs?

On 2011-02-19, at 3:23 AM, Thomas Hallgren wrote:

> Hi David,
> 
> For the meta-data, order doesn't matter since that would break the whole idea 
> of using a SAT algorithm to come up with a resolution. p2 will build a set of 
> all UI's in the repository (composite or not), and then feed that to the SAT 
> solver. The solver then comes up with a plan. The order of children doesn't 
> affect the content of the set.
> 
> For the artifacts, I know that url's with 'file:' are consulted first so that 
> unnecessary download traffic is avoided. I'm almost certain that with the 
> 'file' priority out of the way, the artifact repositories are consulted in 
> the order they are listed.
> 
> Regards,
> Thomas Hallgren
> 
> On 2011-02-19 08:01, David M Williams wrote:
>> 
>> In particular, is it part of the "spec" or API? (That is, I'm not just 
>> asking about current implementation). 
>> 
>> I think this issue will become more relevant, especially for eclipse.org, 
>> now that p2 is getting "old" :)  because some repos that were on 'downloads' 
>> should at some point move to 'archives'. 
>> 
>> Let me elaborate. In a composite repo, many of us might have child repos 
>> that might be similar to the following fictional URLs ... 
>> 
>> <children size='3'> 
>>    <child location='http://archive.eclipse.org/webtools/R3.2.0/' /> 
>>    <child location='http://archive.eclipse.org/webtools/R3.2.1/' /> 
>>    <child location='http://download.eclipse.org/webtools/R3.2.2/' /> 
>> </children> 
>> 
>> Is that order, above, treated differently than the order, below? Which repo 
>> is searched (or matched) first for artifacts? 
>> 
>> <children size='3'> 
>>    <child location='http://download.eclipse.org/webtools/R3.2.2/' /> 
>>    <child location='http://archive.eclipse.org/webtools/R3.2.1/' /> 
>>    <child location='http://archive.eclipse.org/webtools/R3.2.0/' /> 
>> </children> 
>> 
>> This can become important, for example, if some artifact is the same in all 
>> three repositories .... that is, the version/qualifier is unchanged. If the 
>> "archive" repos are tried first, then the result would not be mirrored, and 
>> always come from eclipse.org directly, it seems. The opposite would be 
>> desired, that 'downloads' repos would be "searched/matched" first, and if 
>> found there, then, via the magic of the mirrors URL, would have a chance of 
>> coming from a mirror, thus being faster for many users (and off-loading some 
>> bandwidth from eclipse.org). 
>> 
>> So, is there a way to make sure 'download' URLs are matched first? Should 
>> they come first in list, or last ... or is the outcome indeterminable? 
>> 
>> Any advice? 
>> 
>> Feel free to comment in bug 330134 ... which was opened some time ago to 
>> "investigate" this issue ... but, I'm hoping some p2 expert knows the 
>> answer, and I won't have to investigate :) 
>> 
>> https://bugs.eclipse.org/bugs/show_bug.cgi?id=330134 
>> 
>>   
>> Thanks, 
>> 
>> 
>> 
>> _______________________________________________
>> p2-dev mailing list
>> [email protected]
>> https://dev.eclipse.org/mailman/listinfo/p2-dev
> 
> _______________________________________________
> p2-dev mailing list
> [email protected]
> https://dev.eclipse.org/mailman/listinfo/p2-dev

_______________________________________________
p2-dev mailing list
[email protected]
https://dev.eclipse.org/mailman/listinfo/p2-dev

Reply via email to