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multiple writes in a short period cause db instability



working on a new build with the following software:
OpenLDAP-2.2.15
db-4.2.52 w/ patches
(other components are included but do not relate to the current issue:
cyrus-sasl-2.1.19, heimdal-0.6, openssl-0.9.7d)

build on the following hardware:
OS= Redhat 7.3
processor=2.8ghz
memory=1gig


some of the config info that I am using:
DB_CONFIG:
set_cachesize 0 300000000 10
set_lg_regionmax 262144
set_lg_bsize 2097152

partial slapd.conf(db portion):
threads 20
database        bdb
lastmod on
checkpoint 1024 5
cachesize 30000
idlcachesize 30000

some of these were guessed, based on hardware and software
configurations of others that I found on the net using similar
hardware.

Reads are super fast.. I mean stupid fast! .. never seen it perform
this well.. ever.
a db_stat -m in the database directory shows:
357MB 644KB 540B        Total cache size.
10      Number of caches.
35MB 784KB      Pool individual cache size.
0       Requested pages mapped into the process' address space.
35M     Requested pages found in the cache (100%).

Writes work, as long as its only a few ... but if I try to add 100 user
accounts using ldapadd -f file.ldif .. it bombs out fairly quickly, with
no obvious errors(loglevel -1).  The technical term "bombs" is defined
as, slapd stops responding, but is still running.

I need to run a db_recover on the db before slapd will come up
properly.

what other information would I need to provide so that I or someone
else can help me diagnose this problem.

Thanks


Jonathan Higgins
IT R&D Project Manager
Kennesaw State University
jhiggins@kennesaw.edu