Performance cuestions about ds.

[Julio Gómez Belmonte]

Hello everybody, 

This is my first message to the list, so I hope don't make recurring questions. 

My question concerns the performance of directory server, I have a directory with a large
number of entries, ~ 20,000 objects. My question is: When I receive a too large query, the
directory will be suspended until they answer this query. I could see that there are
options to determine the threads that will use the directory (nsslapd-threadnumber),
persistent searches and apply administrative limits to the queries. I am evaluating what
changes to implement but I have several doubts. When I run the directory, I get a single
process (ns-slapd) which is consuming 100% CPU when doing too long queries, if we have a
multi-thread support, should appear multiple processes or Directory threads (ns-slapd)?
Recommendations that could be followed in a case like this? 

Thanks and best regards,

[Rich Megginson]

----- "Julio Gómez Belmonte" <julio(a)openinside.es&gt; wrote:

>  Hello everybody, 
>  
>  This is my first message to the list, so I hope don't make recurring
>  questions. 
>  
>  My question concerns the performance of directory server, I have a
>  directory with a large number of entries, ~ 20,000 objects. My
>  question is: When I receive a too large query, 
Can you be more specific about what you mean by "too large query"?

>  the directory will be
>  suspended until they answer this query 
What is your platform?  What version of directory server?  How do you know the directory
server is suspended?

>  I could see that there are
>  options to determine the threads that will use the directory
>  (nsslapd-threadnumber), persistent searches and apply administrative
>  limits to the queries. 
Did you change any of these settings from the defaults?

>  I am evaluating what changes to implement but I
>  have several doubts. When I run the directory, I get a single process
>  (ns-slapd) which is consuming 100% CPU when doing too long queries, 
More details please - search base, scope, filter - how many entries match the query - what
user are you running as - have you changed any of the default administrative limits,
database caching options, etc. etc.

>  if
>  we have a multi-thread support, should appear multiple processes or
>  Directory threads (ns-slapd)? 
single process with multiple threads

>  Recommendations that could be followed
>  in a case like this? 
>  
>  Thanks and best regards,
>  
>  --
>  389 users mailing list
>  389-users(a)redhat.com
>  https://www.redhat.com/mailman/listinfo/fedora-directory-users

[Peter Grandi]

> >> On Mon, 15 Jun 2009 10:34:23 +0100 (GMT+01:00), Julio Gómez
> >> Belmonte <julio(a)openinside.es&gt; said: 
>  a directory with a large number of entries, ~ 20,000
>  objects. 
That is a directory of a very small size. 'grep' of a 20,000
LDIF text file takes very little time.

>  My question is: When I receive a too large query, the
>  directory will be suspended until they answer this query. 
That depends on how it is configured. And it is hard for me to
imagine a realistic query over 20,000 records that takes a
significant amount of time.

>  [ ... ] When I run the directory, I get a single process
>  (ns-slapd) which is consuming 100% CPU when doing too long
>  queries, [ ... ] 
At a site I am familiar with the FDS 'slapd' *always* consumes
100% CPU time (RHEL 4), even if the queries are very simple
lookup ('passwd' emulation) and there are only a few queries per
second. I suspect a bug in 'slapd', and I looked briefly into it
and it seemed to me either a busy-lock bug or a a case where the
DB indices get corrupted.