Content-Type: text/plain Content-Transfer-Encoding: quoted-printable On Tue, 2002-09-10 at 11:03, Stanley Hopcroft wrote: > Dear Sir, >=20 > If you don't mind the unsolicited question, >=20 > On Tue, Sep 10, 2002 at 10:57:22AM +0930, Iain Buchanan wrote: >=20 > > Or you could open a 2 way pipe to rrd, and read and write to / from it > > that way. I've used this method very successfully in perl, so I imagin= e > > it would work ok in C too. >=20 > would you mind saying a few words why you would choose duplex pipes over=20 > using the Perl bindings to the shared library (RRDs::create RRDs::update=20 > etc) ?
I first tried system calls from perl, one for every update! But they are very time consuming, especially since I wanted rrdtool for its powerful graphing capabilities and not so much its storage. I already had data stored in another database, and so when I added it to rrdtool, I was doing nearly 10^6 updates at once. Calling system this many times is _very_ slow. So then I lumped some of the updates together into one system call, but it was still a little too slow. I then came across this near the top of rrdtool manual: "FUNCTIONS "While the man pages talk of command line switches you have to set in order to make rrdtool work it is important to note that the rrdtool can be 'remote controlled' through a set of pipes. This saves a considerable amount of startup time when you plan to make rrdtool do a lot of things quickly..." Since it took a relatively short amount of time to alter my program to use pipes, and since it was successful, I didn't see the need to spend time and effort on other methods. So it was the order in which I read manuals. Had I read about Perl bindings earlier, I may have tried them first! Regards, Iain Buchanan -- Attached file removed by Listar and put at URL below -- -- Type: application/pgp-signature -- Desc: This is a digitally signed message part -- Size: 232 bytes -- URL : http://www.ee.ethz.ch/~slist/pantomime/12-signature.asc -- Attached file removed by Listar and put at URL below -- -- Type: application/pgp-signature -- Desc: This is a digitally signed message part -- Size: 233 bytes -- URL : http://www.ee.ethz.ch/~slist/pantomime/13-signature.asc -- Unsubscribe mailto:[EMAIL PROTECTED] Help mailto:[EMAIL PROTECTED] Archive http://www.ee.ethz.ch/~slist/rrd-users WebAdmin http://www.ee.ethz.ch/~slist/lsg2.cgi