On Mon, 2003-09-15 at 14:50, Peter C. Norton wrote:
On Fri, Sep 12, 2003 at 05:56:00PM -0400, Barry Warsaw wrote:
On Fri, 2003-09-12 at 17:40, Harald Meland wrote:
Hence, I think it makes more sense to have the default be "do fsync(2)", and let any performance-conscious site decide whether it wants to explicitly value performance over safety.
Except that when I did some very simple tests, I saw a 97% hit in performance with fsync turned on. This on a RH9, ext3 Linux box of the Dell Optiplex variety. That makes me very nervous to add in a patch release that won't have any beta testing. I've also never seen the bug on python.org, which may or may not be representative of the world at large.
Wow. 97%? That's way too high. I'd expect about 50% at worst - for the extra sync to disk when it enters mailman's queue and one more to flush the message when its made it though the outbound queue to the MTA. This is just a question, because I still don't know much about the mm 2.1 internals, but is there a chance you're sync()'ing more often then you need?
It's possible -- I don't have my test script any more. I just added a flush before closing the config.pck file and I think that will help much more than the sync. IIUC, there's really only a narrow window of opportunity for corruption that sync will solve, and if you're worried about that, you really should be on a UPS and possibly a sync'ing file system.
-Barry