Yeah, I was unsure about whether or not the o/s (slackware v8.0) would buffer the writes - not syswrite - if they occured concurrently, which is why I was looking into flock use.
Many thanks Bob Andy On Thu, 15 Nov 2001, Bob Showalter wrote: > Date: Thu, 15 Nov 2001 10:40:17 -0500 > From: Bob Showalter <[EMAIL PROTECTED]> > To: 'Andy McDowell' <[EMAIL PROTECTED]>, [EMAIL PROTECTED] > Subject: RE: Some advice needed on file locking with modperl'ed code > > > -----Original Message----- > > From: Andy McDowell [mailto:[EMAIL PROTECTED]] > > Sent: Thursday, November 15, 2001 6:37 AM > > To: [EMAIL PROTECTED] > > Subject: Some advice needed on file locking with modperl'ed code > > > > > > Hi All, > > > > I am writing a modperl webapp (the new web interface for the > > RipeNCC whois > > database server) and I have need to store some data to a file. > > Nothing heavy, just a few one liners like user query strings, > > screen used, > > server process time and a few others to do some analysis work > > on potential > > bottlenecks and whois query trends. > > > > The page will take about 5 hits a second when put into > > production. Since its > > modperl, this means multiple instances of page will be > > running concurrently on > > the webserver. > > > > Now the question: > > > > Will I need to use File::Flock to avoid write problems by > > simultaneous writes to > > the one file by concurrent instantiantions of application? > > Yes, I would recommend using locking. If the processes are appending > to a log file, you can get away without locking if you use unbuffered > writes (i.e. syswrite()) and make only a single call to write your > log data. The kernel will keep these from getting intermixed. > > If you do use locking, you need to be sure the lock gets released > at the end of the request, which can be an issue since the Apache/mod_perl > process is long-lived. The easiest way IMO is to localize the file > handle, so Perl will automatically clean it up no matter how your > scirpt ends. If using Apache::Registry, you can also put your close/ > unlock in an END {} block (see mod_perl manpage). > > -- > To unsubscribe, e-mail: [EMAIL PROTECTED] > For additional commands, e-mail: [EMAIL PROTECTED] > ---------------------------------------------- Andy McDowell. RipeNCC. PH: +31 (0)20 535 4444 The difference between wisdom and foolishness, is knowing when to keep your mouth shut. -- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
