Roughly how many users should Samba 4.0 be able to handle?

[Michael Wood]

Hi

On 21 January 2013 08:07, Matthieu Patou <mat at samba.org> wrote:
> On 01/19/2013 03:20 AM, Michael Wood wrote:
>>
>> Hi
>>
>> Thanks for the reply.
>>
>> On 17 January 2013 22:03, Matthieu Patou <mat at samba.org> wrote:
>>>
>>> On 01/17/2013 06:47 AM, Michael Wood wrote:
>>>>
>>>> I'm trying to get an idea of how many users a Samba 4.0 server should be
>>>> able to handle.
>>>>
>>>> In the past (one of the alphas) I tried adding about 40000 users and
>>>> Samba
>>>> slowed to a crawl.  I can't remember the details.  Just that I had to
>>>> roll
>>>> back to by last backup to fix the performance again.
>>>
>>> So due to indexing 40 000 users will result into 200 000 ldb entries at
>>> least and I suspect 400 000 worst case.
>>
>> Ouch!  That sounds like a lot.
>
> Indexes ... 1 entry has a couple of indexed attributes and still we are not
> honoring all the indexing flags (ie. index things like cn=mat*)

OK

>>>> I've compiled 4.0.1 and am busy adding 5000 users to my 1200 existing
>>>> users
>>>> (but on a test machine) to see what happens, but if anyone is running
>>>> Samba
>>>> 4.0 with large numbers of users I'd like to hear about it.
>>>>
>>>> Also, I know Matthieu's been working on optimising the ldb indexing
>>>> code.
>>>> Has that made it to master yet?
>>>
>>> No but it's in process, feel free to try my ldb_perfs branch in my git
>>> repo
>>> to see.
>>
>> I tested adding 5000 users to the existing 1200 and it did not seem to
>> have an impact on the speed.  I am not planning to try 40000 again
>> soon, though.
>
> No impact on speed ? you mean no big difference ?

Sorry, I was unclear.  I have not tested your ldb_perfs branch.  What I
meant was that after I added the 5000 extra users, the speed of
authentication did not seem to be worse than it was before adding the
5000 extra users.  So maybe Samba has improved since I last tried with
40000 users, or maybe it would get bad if I added another 35000 users.
Either way, 5000 users is fine for me for now.

> For the adding part I'm not surprised actually because I took the decision
> to even potentially make write a bit slower in order to make read quicker.
> And also you need to reindex the database to feel the difference ...
>
> One more question are you adding all the users in 1 transaction ?

The speed of adding the users is not really a problem for me, since it's
a once-off thing.  I was adding them by calling samba-tool user create
for each user, so one user per transaction.

-- 
Michael Wood <esiotrot at gmail.com>