[ZODB-Dev] Use of fsync in FileStorage

[Shane Hathaway]

On Wednesday 28 July 2004 15:47 pm, Tim Peters wrote:
> Any use of os.fsync is clearly a txn-rate disaster on my WinXP box.  It
> would be great if readers here tried it on their boxes and reported
> results: various Linux flavors with various filesystems, Solaris variants,
> Windows boxes with "serious" disk systems, whatever matters to you in
> practice.

Here are my results for 10,000 transactions on a 1 GHz Athlon, Linux desktop 
using Reiserfs on a 40 GB drive.

One fsync: 76.3015 seconds, 131.059 txn/sec
Two fsyncs: 86.915 seconds, 115.055 txn/sec
No fsyncs: 9.38018 seconds, 1066.08 txn/sec

The first two tests made the hard drive work continuously.  In the third test, 
the hard drive sat idle except for a commit every 5 seconds.

If you're interested in the results, I could also try this test on a box I've 
been playing with: a dual 2.4 GHz Xeon hyperthreaded SuSE box with 2 GB RAM 
and 4 SATA drives in a RAID-0 configuration.  It can write 180 MB/s to its 
900 GB array.  It screams like no other.  (Literally--the fans are really 
loud!)  Or I could try it on the Gentoo box that actually runs Zope, a 333 
MHz Pentium II with 128 MB RAM and 11 GB hard drive space. :-)

Shane