RE: transaction backoff problems (ITS#2741)

[hyc@symas.com]

> -----Original Message-----
> From: Jong [mailto:jongchoi@OpenLDAP.org]

> Looks it is related to the transaction backoff patch.
> In fact, the paramters of the transaction backoff themselves need to
> be self adjusted. For example, with a parateter set
> empirically optimized
> for back-bdb does not work well with back-hdb, because they have
> different intensity of contention.
> Maybe higher randomness or throttling is needed, but I guess
> that this is
> the case
> in which the contention is too high, that even backoff doesn't help
> (I'm not familiar with -I option, though).
> Without backoff, we might see even more contention.

Exchanging the order of the yield/backoff calls seems to have fixed this
problem. (Do the ldap_pvt_thread_yield() first.) Maybe select() does not
yield on my system.

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