I'm using OpenLDAP 2.4.7 with BerkeleyDB 4.6 on Solaris-10 hosts. We haven't been using it in production so I don't have any real experience with the performance under load. I'll be looking into doing some simulated load tests later. Right now, I'd like to understand more about performance tuning.
I'm trying to follow the instruction in the FAQ or OpenLDAP Software 2.4 Administrator's Guide section 19.4.1.1 Calculating Cachesize but can't find information that is needed to calculate the cache needed for various indexes. In particular the formula given near the end of that section talks about the "Number of hash buckets". I've found something that could be it from running db_stat -m command's output, but that seems to be a single number for the whole database not one per index. Would someone point me in the right direction?
BTW, I get much larger cachesize using the Admin Guide/FAQ method vs. the method Quanah Gibson-Mount wrote about in this mailing list. (du -c -h *.bdb in the database directory) Is that expected?
I assume it would be best to try to optimize the cachesize for all databases. Does this include the log database used for delta-syncrepl?
Also, is it better (performance wise) to give more memory to the db cache or the entry or idl caches? I couldn't find a clear answer from the Admin Guide, FAQ, nor the mailing list.
Finally, is there any difference tuning bdb vs. hdb? I would think not, but since I'm asking...
Thanks. Roy