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From Emmanuel Lécharny <>
Subject Re: Attribute filtering handling...
Date Thu, 13 Dec 2012 09:01:10 GMT
Le 12/11/12 2:09 PM, Kiran Ayyagari a écrit :
> On Tue, Dec 11, 2012 at 4:11 PM, Emmanuel Lécharny <>wrote:
>> Le 12/11/12 11:02 AM, Kiran Ayyagari a écrit :
>>> On Tue, Dec 11, 2012 at 3:23 PM, Emmanuel Lécharny <
>>> wrote:
>>>> But, and there is a big but, when processing a search request, we do a
>>>> direct lookup from the backend, and we are not going through this chain.
>>>> What happens is that we are building a list of filters, and we apply
>>>> this list of filters on every entry fetched from the backend doing a
>>>> direct lookup. So the filter added by the SchemaInterceptor should also
>>>> do this filtering.
>>>> as the filtering is only applicable for search(and lookup) why not apply
>>> this logic in the cursor
>>> after evaluating an entry, I know that this filtering logic was scattered
>>> before but with all that
>>> moved to a utility class I think using that inside the cursor is the
>> right
>>> thing rather than doing it in an
>>> interceptor
>> Because Lookup does not use a cursor at all :/ OTOH, cursors are based
>> on lookup (but not the same as for the lookup() operation.

but unlike in lookup(LookupOperationContext) we don't need to filter anything in lookup(id)

Yep, true. 

Btw, I'm done with the Lookup Cleanup (well, I hope). 

We don't filter the attributes in the backend anymore, it's all done in the SchemaInterceptor.

In the process, I discovered that a lookup going throug the ACI interceptor was not going
through the chain, as we were doing a direct fetch from the backend, bypassing *all* the interceptors
That says two things :
o we don't have a decent test coverage when it comes to ACI
o it's not because some code is 7 years old that it's bug free ! :)

As a direct consequence of the cleanup, a lookup operation is now 10%
faster. Some numbers :
- a getRootDSE, no filtering : 242 000 lookup/s
- a lookup on rootDSE, all user attrs (*) : 148 544 lookup/s
- a lookup on rootDSE, all attributes (*, +) : 145 243 lookup/s
- a lookup on an entry, all user attributes (*) : 144 906 lookup/s
- a lookup on an entry, all attributes (*, +) : 140 154 lookup/s
- a lookup on an entry, all atributes, with ACI (*, +)  : 147 362 lookup/s

73% of the time is used to create a clone of the entry we will return,
10% to fetch the entry ID from the backend using the lookup DN, and 15%
to filter the attributes. It's pretty optimal at this point with 98% of
the processing done in areas we barelly can optimize :)

One potential optimization at this point would be to add a parallel data
structure to the entry we fetch, containing flags set to true for
Attributes we want to return and false for those that are filtered
outout. That would spare us the cost of cloning the whole entry, a very
costly operation. It will impact the way we write the response in the
encoder, but I'm quite sure that the gain could be substancial...

I still have to check that lookups on subschemaSubentry is ok, and check
the lookup through the ACI subsystem.

The next step will be to cleanup the search.

Emmanuel Lécharny 

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