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Date: Thu, 18 Apr 2013 09:13:42 -0700 From: quanah@zimbra.com To: ctcard@hotmail.com; openldap-technical@openldap.org Subject: RE: How to improve performance with MDB backend?
--On Thursday, April 18, 2013 3:59 PM +0000 Chris Card ctcard@hotmail.com wrote:
Maybe MDB performance relative to BDB degrades as the database get bigger. From your wiki page: "This particular client has 25,208 entries in their LDAP database". My test database has over 3 million entries (production has nearly 7 million), which take about 20 minutes to slapadd into MDB initially. My machine has 128 Gb RAM and the MDB db size is 429496729600, so slapd can't map the whole db file into RAM.
How big is your DB when loaded vs maxsize? If you are using writemap, the maxsize *must* be larger than the DB size. Also, what OpenLDAP version are you using? That's always important to note.
I'm using openldap 2.4.35.
olcDbMaxSize: 429496729600 and that's the size of the file on the disk too:
-rw------- 1 ldap ldap 429496729600 Apr 18 16:52 data.mdb -rw------- 1 ldap ldap 8192 Apr 18 17:52 lock.mdb
The size of the db files for BDB is about 22 Gb.
Chris