python tests broken (Re: s4:samldb LDB module - "member" trigger)

Stefan (metze) Metzmacher metze at samba.org
Wed Nov 3 08:58:03 MDT 2010


Hi,

> Metze mentioned this patch to me on IRC as he chases down some
> performance issues, and I wanted to comment on it.  He may make further
> comments once he finishes pinning down his issue. 
> 
> The problem I have with the patch is that it seems very inefficient, and
> I wondered if you had considered the O() notation complexity of this
> validation.
> 
> For every member being added, you now do a search on the entry for that
> member, rather than just let ldb_tdb complain about the duplicate
> attribute when we eventually store it.  Why is this?  If an member
> attribute gains 100 members, you now do 100 searches of the DB just to
> check that they are not already there.  The cost of that search is
> rougly proportional to the number of members already being added -
> particularly if done one at at a time, so this seems to be O(n^2). 
> 
> And similarly, whey trying to determine if the member attribute would
> conflict with a primaryGroupID, why not first (and only once) read the
> sid of the entry, and then compare with the primaryGroupID of the
> target?
> 
> Surely this would be faster than dereferencing the member attribute,
> only to form up a SID and compare it with our own DN?

I fixed the problem, but I can't verify my changes with make test.
http://gitweb.samba.org/?p=metze/samba/wip.git;a=commitdiff;h=61a818143ba777

I discovered that 21 of 30 python tests are broken, currently!
The piping through filter-subunit just ignores the errors...

This patch add the logic to let us notice the errors again.
http://gitweb.samba.org/?p=metze/samba/wip.git;a=commitdiff;h=4aa453ca538e77d

Most tests fail with:

[25/30 in 1m46s, 18 errors] samba4.ldap.acl.python(fl2008r2dc)
Traceback (most recent call last):
  File
"/home/metze/devel/samba/4.0/master4-drsuapi/source4/dsdb/tests/python/acl.py",
line 12, in <module>
    samba.ensure_external_module("subunit", "subunit/python")
  File
"/home/metze/devel/samba/4.0/master4-drsuapi/source4/bin/python/samba/__init__.py",
line 319, in ensure_external_module
    __import__(modulename)
  File
"/home/metze/devel/samba/4.0/master4-drsuapi/source4/bin/python/samba/../../../../lib/subunit/python/subunit/__init__.py",
line 128, in <module>
    from testtools import content, content_type, ExtendedToOriginalDecorator
ImportError: No module named testtools

Jelmer can please take a look at this and fix it?

metze

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