[Fedora-directory-users] Performance

[David Boreham]

Vampire D wrote:
> We will not be using LDAP in the traditional sense.
>  
> Instead of authentication, we will be using it to perform lookups upon 
> incoming mail.
> We plan on having tens of thousands of email addresses stored in LDAP, 
> every message that comes in is verified via LDAP that it is allowed, 
> and then it is processed by our system.  We plan on caching entries 
> (positive and negative) for 24 hours, so as long as the look up has 
> been done in the last 24 hours and the 1M record cache isn't exhausted 
> it will not perform a look up.  This should cut down a lot of the 
> demand.  Initially we are looking at about 100k lookups an hour, as we 
> expand the service that can go up by 50-100k at a time.
It isn't clear to me how often you'll be adding, deleting or modifying 
the LDAP entries.
Your search workload seems very low -- you should be able to achieve on 
the order
of 10-50k searches/s on modern hardware with on the order of a million 
entries.
However, like all databases that use a WAL, you will struggle to achieve 
a few
hundred writes/s without very high end storage hardware (solid state 
disks for example).

It may not be worthwhile caching search results inside your application 
because
the LDAP server is caching too. You'd only save the network round trip 
overhead.