[Koha-devel] Search speed

[Paul A]

I have progressed a little further on this subject using multiple parallel 
tests for from 0 to ~25k biblios on a new, relatively fast server. In brief:

3.08 averages 0.88 secs per search
3.18 averages 5.06 secs for the same searches, but...
3.18 averages only 1.52 secs if I turn off facets.

Facets appear to have a huge overhead in various components of Zebra, to 
the point where a single core of a multiple processor CPU gets overwhelmed, 
but does not share the load with other totally idle cores.  Intel tell me 
that this is not fixable through any hardware/BIOS config and they are not 
aware of a Linux "standard library" that deals with processor 
affinity.  I've searched around a little and found mentions for c and 
FORTRAN (marvelous old memories for me!) but so far nothing totally 
specific for Perl. taskset and sched_setaffinity might be usable at system 
level, and I might have a look at pthread_setaffinity_np.3.gz

I've posted test results, notes and three sets of NYTProf analysis at 
<http://navalmarinearchive.com/z_koha/> and would appreciate if anyone has 
any suggestions or comparative tests and outcomes.

Thanks and best regards -- Paul