Dual Processors Mod Perl
Hey ho, Sorry if this is an FAQ or a little OT.. We're thinking of moving a couple of servers and one of the possibilities is a dual PIII box (Compaq AFAIK, probably pretty standard rack box) I'm just wondering how Linux (RedHat 7.2) deals with dual processors, and whether any of the following will have problems: - Apache mod_perl themselves (currently use v1's rather than 2's) - LibXML,XSLT etc running under mod_perl - A whole bunch of CPAN mods! Does linux just take care of 2 proccessors or does the code have to be compatable? Also out of pure curiosity does it actually double the capabilities of the machine? (The jump from our current 128Mb to 1GB of RAM will - I'm guessing - have more of an impact ;-) Cheers.. Jimbo _ Jim Morrison Technology Development Partner Isotope Communications 9 Green Park Station Bath, BA1 1JB, UK +44 (0) 1225 444 674 http://www.mediaisotope.com/
Re: Dual Processors Mod Perl
I have have had about 50 dual CPU/1GB ram boxes running a combo of linux/freebsd over the least few years (20 currently). All running modperl/apache. I always go Dual-CPU. Its not that pricey. We have had no SMP problems at all and I think it performs much better, about 30% higher transaction rate. To me hte RAM is more important then the CPU dualism. But in general on a high volume system you are probably going to be more bound by Disk I/O etc then CPU. Our code base is pretty huge and we run more modules from CPAN then I can count including all the XML stuff ( LibXML, SOAP etc etc etc ). John- On Thu, 13 Mar 2003 15:15:34 - Jim Morrison [Mailing-Lists] [EMAIL PROTECTED] wrote: Hey ho, Sorry if this is an FAQ or a little OT.. We're thinking of moving a couple of servers and one of the possibilities is a dual PIII box (Compaq AFAIK, probably pretty standard rack box) I'm just wondering how Linux (RedHat 7.2) deals with dual processors, and whether any of the following will have problems: - Apache mod_perl themselves (currently use v1's rather than 2's) - LibXML,XSLT etc running under mod_perl - A whole bunch of CPAN mods! Does linux just take care of 2 proccessors or does the code have to be compatable? Also out of pure curiosity does it actually double the capabilities of the machine? (The jump from our current 128Mb to 1GB of RAM will - I'm guessing - have more of an impact ;-) Cheers.. Jimbo _ Jim Morrison Technology Development Partner Isotope Communications 9 Green Park Station Bath, BA1 1JB, UK +44 (0) 1225 444 674 http://www.mediaisotope.com/
Re: Dual Processors Mod Perl
Jim Morrison [Mailing-Lists] wrote: [...] I'm just wondering how Linux (RedHat 7.2) deals with dual processors, [...] Does linux just take care of 2 proccessors or does the code have to be compatable? If you are using a non threaded mod_perl, which is the case with - mod_perl 1.0 - mod_perl w/ prefork mpm and you don't spawn your own threads, which you can. then your code will work all the same. The only difference is that if your code had any race conditions, chances are higher that you will hit them on a machine with more than one CPU. On race conditions see: http://perl.apache.org/docs/1.0/guide/debug.html#Critical_Section If you use mod_perl 2.0 w/ threaded mpm, your code and all libs that you use have to be re-entrant and thread-safe, no matter whether you are using a single- or multi-processor machine. Again if you code does have thread related problems, you are more likely to see them on an SMP machine. __ Stas BekmanJAm_pH -- Just Another mod_perl Hacker http://stason.org/ mod_perl Guide --- http://perl.apache.org mailto:[EMAIL PROTECTED] http://use.perl.org http://apacheweek.com http://modperlbook.org http://apache.org http://ticketmaster.com
