RE: Performance of MDB and BDB Please suggest?

[Chris Card <ctcard@hotmail.com>]

Hi all,

I am also doing some testing with mdb at the moment, and my initial testing indicates that mdb is faster for reads but slower for writes than bdb.
I am using openldap 2.4.32 on centos 6, on a 24 core box with 132 Gb RAM.

My test directory has ~ 3 million entries, and I loaded it into mdb using slapadd which took over 2 days (by comparison, the same load into bdb takes 2-3 hours).
(as an aside, I initially tried using 2.4.31, but slapadd crashed after having loaded about 90% of the data, and this was repeatable).

On disk the directory takes up ~ 13 Gb for mdb and ~ 18Gb for bdb.
Cache size for bdb is set to 63 Gb in DB_CONFIG.
Directory size for mdb is set to 63 Gb

Adding 120000 entries from an ldif file using ldapadd took ~ 10 minutes for mdb and ~ 2 minutes for bdb.
Deleting 120000 entries using ldapdelete took ~ 10 minutes for mdb and ~ 3 minutes for bdb

A search returning ~ 300000 DNs took ~ 6 seconds for mdb and for bdb it took ~ 6 minutes from a cold start of slapd and then ~ 35 seconds.

Chris