RE: BDB Locking problem

["Howard Chu" <hyc@highlandsun.com>]

> -----Original Message-----
> From: owner-openldap-software@OpenLDAP.org
> [mailto:owner-openldap-software@OpenLDAP.org]On Behalf Of Sean O'Malley

> Im running this rather large database. I am getting the
> sched_yield()                           = 0
> error with openldap 2.1.12., bsb-4.1.x, RH7.3
>
> I thought this bug was fixed?? I guess not.

I hesitate to call it a "bug" when you try to run a configuration that is too
large for your machine to handle. That is "user error" - you should read the
BDB documentation; it is quite explicit about choosing a DB cache size that
is small enough to fit in your physical RAM.
>
> I read something where you need to increase the maximum number of locks
> for the bdb database but how do you set it in the slapd file?

No. The default is something like 1000 concurrent locks; I think you would
need to be running with about 300 threads to exhaust that limit. Just a wild
guess. The only time I've seen the number of locks be a problem was with BDB
3 because it was leaking them.
>
> It was working fine before i axed the 2Gig swapfile I had set up with the
> same configuration file. ... Is this automatically configuring itself on
> how much RAM you have available or something along those lines?

No. There is no automatic configuration for memory size. Even if portable
code could be written to determine the amount of free RAM on a machine (which
is a hassle in itself) there's no way to automatically set the policy -
should the server use all of the RAM? Should it use only half? Leave some for
other processes? How much should it leave?

In this day and age, computer systems are getting faster and more capable,
but they still do not eliminate the need for a sensible, intelligent person
to run the show. Computers will *never* be "smart enough for any fool to
use."

Pardon me for a moment while I step on my soapbox - the whole Free Software
phenomenon proves something that I've said for a long time - "Intellectual
Property" doesn't have much intrinsic value. It is nowhere near as valuable
as "Intellect." This is why I believe ultimately the Free Software model will
succeed, and businesses based on the old proprietary model will ultimately
fail. Companies pushing proprietary software take the attitude that it is the
Intellectual Property they create wherein their value resides. The fact that
Free Software-based enterprises are becoming more and more successful shows
how wrong this is, IP is really a cheap commodity. The real value of any
enterprise is in its Intellect, its talent base. And the best piece of
software in the world is all just a bunch of colorful garbage, in the hands
of an idiot. Without Intellect, Intellectual Property is worthless.

When you go looking for a software package, don't just look for which one has
the most automation. Don't believe that because it has all that automation,
it will make your job or your life easier. It won't. Many times it will make
it harder, because it will automatically do a task in a manner unsuitable for
your needs. This is true of programming languages, spreadsheets, databases,
and any other system of greater than trivial complexity. There is no
substitute for using your own brain to get a job done right.
</soapbox>

  -- Howard Chu
  Chief Architect, Symas Corp.       Director, Highland Sun
  http://www.symas.com               http://highlandsun.com/hyc
  Symas: Premier OpenSource Development and Support