Re: htdig: 3.1.b2 -> 3.1.b3 performance degradation +

Gilles Detillieux (
Tue, 22 Dec 1998 13:19:43 -0600 (CST)

According to Maren S. Leizaola:
> Neither CPU or memory are the issue here... htsearch maxes out the SCSI
> bus for up 15 seconds at a time... I think this is due to the new factors,
> which I wanted so much. :)

Memory can be the issue on a demand-paged virtual memory system. If the
program consumes too much memory because of a memory leak, the system
will start paging like mad, which could account for some of the SCSI
bus activity you've seen. What I'd like to know is how much of the
disk I/O is due to excess paging, and how much is due to database I/O.
That's why I was asking for a comparison of performance before and after
applying the memory leak patch. Theoretically, it could account for
about half of it, give or take some. But I'd like to know what it really
accounts for in practise.

If performance is still really bad, even with the memory leaks corrected,
then it's going to take some work to optimise the fetching of date and
backlink counts without causing all the extra overhead of loading entire
DocumentRef records from the DB.

Gilles R. Detillieux              E-mail: <>
Spinal Cord Research Centre       WWW:
Dept. Physiology, U. of Manitoba  Phone:  (204)789-3766
Winnipeg, MB  R3E 3J7  (Canada)   Fax:    (204)789-3930
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