RE: back-bdb future

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

> -----Original Message-----
> From: Jonghyuk Choi [mailto:jongchoi@us.ibm.com]

> It seems that deadlock freedom is not guaranteed if a DB access
> is outside transaction when we use the BDB transactional store.
> The deadlock case in 8 way machine is somewhat strange.
> It was only search threads that were attempting to open the
> index database.
> If deadlock occurs among search threads, timeout for txns
> would not help.
> Any idea why only search threads reach deadlock ?
> Unless we use CDB, even search only case not free from deadlock ?
> - Jong

Um... I wonder if this is because we make BDB wrap all DB->open calls in
their own transactions? (See back-bdb.h, DB_AUTO_COMMIT.) This may be the
problem; we should have propagated the DB_TXN from bdb_index_values into
bdb_db_cache. For bdb_index_param which is used for searches, we shouldn't
use a txn. I've got this patched, can you see if it makes a difference?

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