transaction backoff problems (ITS#2741)

[hyc@OpenLDAP.org]

Full_Name: Howard Chu
Version: 2.2.1beta
OS: Linux
URL: 
Submission from: (NULL) (67.115.65.234)
Submitted by: hyc


While running test008 with a large number of iterations (-l 2000) I see the
operation throughput decrease over time. There are long idle periods when all
slapd threads are asleep, and then a short burst of activity accompanied with
DEADLOCk messages, and then another long idle period. At least one thread ought
to be active at all times, but it appears that all the writers have gone to
sleep, for approximately equal amounts of time.