[PATCH] Re: Proposed ldb 1.1.30 and tdb 1.3.13 (improve AD DC search performance, make multi-process)

[Andrew Bartlett]

On Tue, 2017-04-11 at 18:08 +0200, Stefan Metzmacher wrote:
> 
> Here's an update on current master.
> 
> I've added the run-fcntl-deadlock as test.
> 
> I still want to run the standalone make test of tdb and ldb on
> solaris,
> before we push this and have a closer look at the ldb changes.

Thanks!

Finally, this is may also be a 'data corruption' issue:  

My theory is that because there is no read lock held, the index might
refer to different records compared with the data.  Sometimes that will
fall back to a traverse (we do that on errors), but sometimes that will
mean we don't return all the records, as we essentially check twice,
both in the index and in the final search filter.  

If a search took a long time, a modify could happen between those two
points, and while the modify would be atomic, the search would not be
atomic.

On the flip side, with this patch reads will block all writes for
longer.

BTW, A test for the LDB changes is in the cmocka thread.  Because LDB
is buggy it passes right now, but fails if we do have the ldb fix but
don't have the tdb fix. 

Andrew Bartlett

-- 
Andrew Bartlett                       http://samba.org/~abartlet/
Authentication Developer, Samba Team  http://samba.org
Samba Developer, Catalyst IT          http://catalyst.net.nz/services/samba