s4 ldb tdb limits

Oliver Liebel oliver at itc.li
Wed Aug 26 22:21:32 UTC 2015

Am 26.08.2015 um 18:02 schrieb Jeremy Allison:
> On Wed, Aug 26, 2015 at 03:46:41PM +0200, Oliver Liebel wrote:
>> Am 26.08.2015 um 04:34 schrieb Andrew Bartlett:
>>> On Tue, 2015-08-25 at 09:34 -0700, Jeremy Allison wrote:
>>>> Yeah, lmdb and backending with OpenLDAP is our
>>>> long term solution for these limits I think.
>>>> Nadia, any progress report on migrating us over ?
>>> Jeremy,
>>> I should caution you that while moving to lmdb rather than tdb may be
>>> reasonably practical (a prototype has been developed so far), the task
>>> of moving to using OpenLDAP is I feel an order of magnitude larger than
>>> the task to move us to using MIT Kerberos.  Equally, when finished it
>>> promises great improvements, but we should be very clear that it needs
>>> commensurate resources.
>>> The issue is this:
>>> At it's heart, Samba4 turned out to be a series of RPC services
>>> clustered around the LDB module stack.  The vast majority of the
>>> complexity is in that stack.   As I understand it, the OpenLDAP backend
>>> project seeks to 'simply' replace that stack, using a number of Samba
>>> libraries in the process.
>>> I hope this helps give an idea of the scale involved here.
>>> Thanks,
>>> Andrew Bartlett
>> I fully agree with Andrew.
>>  From my point of view (and that of many customers) there are at this point
>> 2 major tasks to get S4 into larger/enterprise scale:
>> - Fast (LM)DB Backend
>> - W2K12 DC compatibility
>> I know for sure how big the task is, to get OpenLDAP as an
>> S4 Backend with full Schema Semantics and DRSUAPI or any kind of DRS
>> working, as Andrew and I already worked a few years ago on the
>> S4/OpenLDAP Backend.
>> And i would love to see OpenLDAP as an S4 Backend, but from a
>> realistic point of
>> view, this task can't be finished very shortly, because its really complex.
>> I think in the meantime it is the best approache,
>> to get the LDB/TDB Stack enhanced / replaced with LMDB,
>> so that large(r) scale Installations could be satisfied.
>> We should get ' the best Database under the hood ' working. The
>> quicker, the better.
>> One side effect: When the S4/OpenLDAP Job is done, we got already a mostly
>> compatible LMDB-Backend inside S4 working.
>> @Andrew, Nadezhda and Jakub:
>> could you please submitt  a full description / explanation  of the
>> minor tasks
>> to get TDB replaced with LMDB.
>> I will try to get some hr, to get this done (but no promises,
>> i'll keep you informed)
> Yeah, I wasn't saying it was going to be easy :-).
> That's why I ust asked Nadia for a status update,
> nothing more :-).

Jakub pinged me, in the next days
he'll bring me up to date about the oustanding
tasks regarding TDB / LMDB  Replacement.

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