Re: Openldap ldbm cache corruption

["Kurt D. Zeilenga" <Kurt@OpenLDAP.org>]

At 09:27 AM 1/12/99 -0800, Kurt D. Zeilenga wrote:
>I'm think we need to completely rethink how our LDBM
>cache design.
>
>1)  I believe we should modify the in-core Entry structure
>to contain dn in both 'provided' and 'normalized' formats.
>The 'provided' format would be used when providing the
>dn in results, but the 'normalized' would be used for
>all operations.
>
>2)  I believe we should consider moving to a per-backend
>reader/writer lock instead of per-entry reader/writer locks.
>I believe per-entry locks are too fine grain and hinder
>preformance.

I think it wise for the frontend to have no knowledge of
the whether the backend is doing per-backend or per-entry
locking.  This would allow some backend's to implement
per-entry locking if the developers wanted to implement
it.

I think back-LDBM should be modified to use per-backend
"balanced" reader/writer locks.

I'm thinking that folks may want to implement a new backend
to take full advantage of the underlying database's caching
and locking.  I would welcome development of non-generic
LDBM implementations.  ie: back-bdb (Berkelely DB 2.x) or
back-whatever.

Kurt