RE: BDB database maintenance

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

> -----Original Message-----
> From: Dave Lewney [mailto:D.M.Lewney@sussex.ac.uk]

> > back-ldbm using Berkeley DB does not generate log files,
> but you still need
> > to tune the dbcachesize, and back-ldbm doesn't offer high
> concurrency or
> > transaction-protected updates. After an abnormal shutdown,
> you generally need
> > to delete the database and start over from scratch, because
> when it gets
> > corrupted there is no telling what's left inside.

> Actually my experience is just the opposite. Load testing a
> v2.0.27 server
> with back-ldbm caused slapd to "run away" (90% CPU). A kill
> -9 followed by
> a restart and all is OK.
>     The same experiment with v2.1.16 with back-bdb causes db
> corruption.
>     Platform - Solaris 8.

Believe what you will... back-ldbm isn't sophisticated enough to detect
database inconsistencies automatically, and has no means to repair itself.
Any errors will only reveal themselves slowly over time. back-bdb will detect
inconsistencies automatically, and you can use db_recover to repair the
damage.

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