Performance tests, openldap slapd vs netscape slapd

["Jeff Weinheimer" <jj_weinheimer@hotmail.com>]

I have been interested in a performance comparison between the openldap 
slapd and the netscape slapd servers.  So I wrote a program in c which 
allows me to add and delete directories of arbitrary sizes and to time 
operations.

My directory consists of two types of entries.
1. Subdirectories which have about 4 attributes
2. Entries which contain about 6 attributes.

My initial test consisted of a tree with the following properties.
1. Each subdirectory contained 5 more subdirectories, except at the final 
depth of the tree.
2. Each subdirectory contained 5 entries.
3. The depth of the tree was built to a depth of 5.

This resulted in a tree with approximately 3900 subdirectories and 19,000 
entries.

For the test, the minimal cache was chosen (netscape has a lower limit on 
the allowed cache size).  That is, each servers cache was set to 1000 
entries and 500k bytes.  This should have minimal impact on the search 
results since almost 23000 entries must be searched for the whole tree.

The results(Athlon 650, Redhat Linux 6.1):

             openLdap                       netscape

AddEntry       1-10 entries/second            25-45 entries/second

DeleteEntry     10-30 entries/second           40-45 entries/second

Search           5700 searches/second            2600 searches/second

DataRead          750 entries/second               800 entries/second

*DataRead corresponds to the number of entries returned per second after the 
search was complete.

Overall I found that it takes much longer to add to the openLDAP slapd than 
netscapes, but that the searches in openldap were twice as fast.  This of 
course if perfectly acceptable since the idea behind LDAP is mostly reading 
and rarely writing.

 One odd thing that I did encounter was with the time it took to add 
entries for openldap.  At first, as more entries were added, it took longer 
and longer to add them to the database.  Then at some point(maybe 4000 
entries) it started taking less and less time to add entries.  This seems a 
bit odd to me.  Does anyone have an explanation for this?

 Any comments on the tests?

 Has anyone else done similar performance tests?

I also encountered a subtle difference between openldap and netscape.
In openldap the DN does not have to contain valid attributes to the schema, 
while in netscape each piece of the DN must be allowed in the schema.  For 
compatibility it seems wise to make sure the DN contains valid attributes.

Jeff Weinheimer

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