Re: Slow delete behaviour

["Andrew Davison" <adavison@ozemail.com.au>]

Oops, never mind.

----- Original Message ----- 
From: "Andrew Davison" <adavison@ozemail.com.au>
To: "openldap-devel" <openldap-devel@OpenLDAP.org>
Sent: Thursday, March 09, 2000 6:12 PM
Subject: Slow delete behaviour


> I'm playing with Ldap-2-devel (latest as of a week or so ago) with
> Sleepycat DB (last v2) and NT4. Adds to LDAP work fine (~150/sec on
> 466 MHz Celery, IDE disk) with just a few indexes and searches also are
> fast. But I find with deletes there is a *warm-up* period of disk
> thrashing before the delete happens that increases with the number of
> entries in the database.
> 
> For example, with 10K test entries the disk thrashes madly for 10 secs
> before the first delete happens,  then the subsequent ones go thru
> merrily enough at about 2/sec. With 100K entries, the disk thrashes
> madly for 10 MINUTES before the first delete happens, the others then go
> 
> thru about 1/sec, which is ok. If I kill the client at this point and
> restart, exactly the same thing happens. There is no VM activity or much
> 
> CPU usage at all, just disk I/O, seems to be scanning something.
> 
> What on earth could be causing this *warm-up* thrashing? Why would it
> happen on only the first delete in a session? Sounds to me like it is
> scanning some index first, but why?
> 
>