Re: (ITS#8977) Make IDL sizes configurable in back-mdb

[quanah@symas.com]

--On Thursday, June 27, 2019 8:56 PM +0000 quanah@symas.com wrote:

> --On Thursday, June 27, 2019 8:35 PM +0000 hyc@symas.com wrote:
>
>> No, because order is irrelevant for these.
>
> Cool, thanks!  I'll continue on with deeper testing then. :)

Given the current implementation of OpenLDAP, this feature is impossible to 
use w/o recompiling OpenLDAP when a change to the IDL size is made.  This 
is because LDAP_PVT_THREAD_STACK_SIZE must be adjusted as well and that 
requires a recompile.

The default size for LDAP_PVT_THREAD_STACK_SIZE is:

( 1 * 1024 * 1024 * sizeof(void *) )

which works for an IDL size of 16 (2^16) which is 65536.

If you change the IDL size, say to 22, then the new IDL size is: 4,194,304. 
We then use this difference to find the offset we need to adjust 
LDAP_PVT_THREAD_STACK_SIZE by:

4194304/65536 = 64

So it needs to be 64 time larger:

( 64 * 1024 * 1024 * sizeof(void *) )


Generally, this feature is simply unusuable (currently) as a tunable given 
the requirement for recompiling OpenLDAP to use it.

--QUanah


--

Quanah Gibson-Mount
Product Architect
Symas Corporation
Packaged, certified, and supported LDAP solutions powered by OpenLDAP:
<http://www.symas.com>