On Sun, 2004-03-07 at 13:34, Perrin Harkins wrote: > Jeffrey W. Baker wrote: > > I wasn't aware of these issues before. Looks like I'll have to use > > BerkeleyDB or Tie::DB_Lock or something. > > On closer inspection I think it's mostly okay because the session object > is supposed to go out of scope and get destroyed (and thus untie) after > every interaction, and the locking should mean that only process is > writing during that time. You could run into trouble though if a > process is able to open for reading and then later do writes without > closing and re-opening the file first, and it looks like that does > happen. This could lead to lost updates from other processes. > > I'd suggest either looking at how MLDBM::Sync works, or using BerkeleyDB > instead. BerkeleyDB can be tricky to get right, but it's significantly > faster than any other storage mechanism supported by Apache::Session.
It's faster in the trivial case, but doesn't exactly scale horizontally, that is to more than one server. I've also seen BerkeleyDB doing seek, read, write, sync in such a pattern that the Linux kernel will starve all other I/O on the machine. But this is a platform-specific trouble :) In any case, it will be a simple addition. -jwb -- Report problems: http://perl.apache.org/bugs/ Mail list info: http://perl.apache.org/maillist/modperl.html List etiquette: http://perl.apache.org/maillist/email-etiquette.html
