large directory cache tuning on Windows 2003
I have some questions about cache sizes for a directory server deployment (2005Q4) on Windows 2003 (customer's choice), provided that the db directory is about 2 Gb with the following layout, in bytes:
37DBVERSION
16,384userRoot_aci.db3
1,286,144userRoot_ancestorid.db3
76,210,176userRoot_cn.db3
168,583,168userRoot_entrydn.db3
1,752,236,032userRoot_id2entry.db3
152,354,816userRoot_nsUniqueId.db3
16,384userRoot_numsubordinates.db3
1,646,592userRoot_objectclass.db3
286,720userRoot_parentid.db3
5,398,528userRoot_uid.db3
- changing allidsthreshold from 4000 to 65000 and reindexing doesn't impact the db directory size since I only have equality indexes on uid and cn.
- According to the tuning guide, the overall directory cache sizes should fit
in 2Gb, but the database cache size shouldn't be set to more than 1Gb.
I would rather tend to set the database cache to about 1,5 Gb and
leave the remaining memory to the entry cache (and so that the slapd.exe process does'nt exceed 2Gb), and thus I wonder what's the best/recommanded strategy in such a case ?
- Should I recommend the customer to purchase lots of memory, to profit
from the Windows 2003 filesystem cache, or should we rather rely on
hardware caches from the disks subsystem ?
