Re: [webmin-l] LDAP Users and Groups module performance

[Murray T. <mtr...@ce...>]

On Sun, 2007-02-25 at 22:49 -0800, Jamie Cameron wrote:
> On 25/Feb/2007 22:19 Murray Trainer wrote ..
> > On Sun, 2007-01-21 at 22:27 -0800, Jamie Cameron wrote:
> > > On 21/Jan/2007 16:11 Murray Trainer wrote ..
> > > > On Fri, 2007-01-19 at 00:23 -0800, Jamie Cameron wrote:
> > > > > On 18/Jan/2007 22:46 Murray Trainer wrote ..
> > > > > > Hi Jamie
> > > > > > 
> > > > > > We now have over 1000 users we manage with the LDAP Users module.
> > > > I
> > > > > > have noticed lately that it is becoming very slow bringing up the
> > > > > > initial screen.  I can imagine things only getting worse as the
> > > > > > directory gets larger.  I haven't checked the queries My guess
> > is that
> > > > > > the module tries to search the LDAP directory for the whole list
> > of
> > > > > > users, then after realising there are too many, it then says there
> > > > are
> > > > > > too many to display and fails.  Even if I set the maximum number
> > of
> > > > > > users or groups to display to 0 or 1 it still takes a fair few
> > seconds
> > > > > > to display the opening screen.  
> > > > > > 
> > > > > > The recommed method is to process each LDAP user entry one at a
> > time
> > > > as
> > > > > > they are returned. The module would stop when it reached the limit
> > > > of
> > > > > > users for that page which could be a configuration value.  The
> > module
> > > > > > appears to be using the NET::LDAP library.  I had a look at the
> > > > > > documentation below and they recommend processing each entry as
> > it
> > > > is
> > > > > > returned:  
> > > > > > 
> > > > > > http://search.cpan.org/~gbarr/perl-ldap-0.33/lib/Net/LDAP/FAQ.pod#USING_THE_CALLBACK_SUBROUTINE_APPROACH
> > > > > > 
> > > > > > If we want 100 users to be displayed on the page we print the first
> > > > 100
> > > > > > entries then quit.  If we want users 100-200 we would ignore the
> > first
> > > > > > hundred entries and print the second hundred, and so on.
> > > > > > 
> > > > > > Hope the above idea has merit and its possible for you to implement
> > > > at
> > > > > > some stage.
> > > > > 
> > > > > Actually, that is what the module already does. The main page does
> > an
> > > > > LDAP search for matching users, and then checks the number of results
> > > > available.
> > > > > If this is higher than the maximum set on the Module Config page,
> > it
> > > > just
> > > > > displays the search form without fetching the full user list.
> > > > > 
> > > > > Of course, for this to be useful I assume that the LDAP server doesn't
> > > > > fetch users from it's database until actually asked to..
> > > > > 
> > > > >  - Jamie
> > > > > 
> > > > 
> > > > If it does things in the sequential manner then I am not sure why it
> > is
> > > > so slow for me.  There is nothing wrong with the performance of the
> > ldap
> > > > server.  I can do an ldapsearch from a client machine and dump the
> > whole
> > > > list of users into a text file in less than a second.  Going into the
> > > > first ldap users and groups screen with the list of users takes > 10
> > > > secs even with the amount of users to display set to 0. I am not sure
> > > > where the bottleneck in performance is?
> > > 
> > > I took another look at the code for this module, and it seems that even
> > > though Webmin just calls the Net::LDAP module's search function, this
> > > takes a long time to respond on large LDAP databases even though no
> > > actual results are requested!
> > > 
> > > However, I managed to find another way to reduce the search size, by
> > > specifying a maximum result size to the LDAP server. This will go into
> > > the next (1.330) Webmin release.
> > > 
> > >  - Jamie
> > 
> > Hi Jamie,
> > 
> > I noticed that you had added the fix above to the 1.328 version.  I
> > downloaded it and tested it.  It displays the initial list of
> > users/groups immediately if it exceeds the limit for the page.  Thanks
> > for your work on that - it will improve things a lot in our setup.
> 
> Excellent .. glad to hear that solved it.
> 
> > I noticed there is now a different Webmin theme by default.  I tried
> > changing to the previous theme and couldn't find it.  All the themes I
> > chose appeared the same to me.  I couldn't change back to the new
> > default theme either.  Not sure the new theme stuff is right?
> 
> Did you use the Change Language and Theme module to switch themes? If 
> you change the global setting in the Webmin Configuration module, it
> can still be over-ridden on a per-user basis by the former module..
> 
>  - Jamie

I just tried the Change Language and Theme module and that seems to work
better.  It's a bit confusing having both options though.

Murray