[389-users] Tuning dbcache size for large directory

[Rich Megginson]

On 11/16/2012 08:33 AM, Howard Chu wrote:
> 389-users-request at lists.fedoraproject.org wrote:
>> Date: Fri, 16 Nov 2012 09:30:26 -0500
>> From: P R <pwrdevman at gmail.com>
>
>> First off, my server is equipped with 12GB of physical memory. From 
>> reading
>> tuning guides online, I’ve found that a starting estimate for the
>> ‘dbcachesize’ = SUM(allDB4files). For one of my directory instances, the
>> id2entry.db4 file alone is ~ 11GB.
>
> Wow, still manually tuning cache sizes, how quaint.
>
>> Performance wise, would it be worthwhile to increase the amount of 
>> physical
>> memory on the server (perhaps 64-128GB)? Or does 11GB for an id2entry 
>> seem
>> like an extremely high value that’s out of the operating capabilities of
>> the directory? Is it unheard of for a production directory server to be
>> equipped with 64GB of physical memory?
>
> Dunno about 389DS, but there are production OpenLDAP installations out 
> there running on 64-core machines with over a terabyte of RAM. (The 
> NoSQL/Big Data guys are just noisy children, really...) They serve 
> directories with hundreds of millions to billions of entries. 11GB 
> sounds pretty trivial to me.
>
> So no, it's not unheard of. It's not even very extreme, really.

Gee, thanks for advertising for OpenLDAP/Symas on the 389 list.