Re: AIX perfomance
Hi Ged, On 9/12/03 at 4:12 PM, [EMAIL PROTECTED] (Ged Haywood) wrote: Roughly what hardware setups do you generally work with, and what differences are notable between Linux and AIX when running mod_perl servers? (If that's not too long a piece of string to measure:). Are there situations where you'd prefer one or the other, if so why? Sorry for the slow response; I've been out of town. Most of my mod_perl/AIX systems are used to generate organizational performance reports, basically data-mart type stuff, which is very DBI (DB2) and computationally-intensive, and also often invlove running COBOL binaries which have been ported from OS/390 and run via RPC::XML. If the need to run COBOL is absent from a project, then I usually deploy on Lintel, since procurement is so much easier. I never rely on OS ditributions of perl, apache, or mod_perl so my working enviroment is always identical. As I mentioned earlier, Rafael should not be experience slowness on AIX unless he's comparing dated RS/6000 hardware with new Intel. Scalability, especially with big SMP iron, still favors the RS/6000 though at a colossal cost. Bill
Re: AIX perfomance
On 9/12/03 at 2:07 PM, [EMAIL PROTECTED] (Rafael Garcia-Suarez) wrote: I've a mod_perl application we've developed on Linux and that we're porting on AIX (4.3.3 and 5.2.0). The AIX boxes are supposed to be more powerful than their Linux equivalents, however the application is strangely slow on AIX -- the httpd configuration being similar. And that's mod_perl 1.28. So I'm asking for the common wisdom about performance issues on AIX. Currently the perl I use is built with gcc and default settings. Should I set -Dusemymalloc=y ? Should I use the xlC or vac compilers ? Should I port everything to mod_perl 2 ? (which I haven't succeeded to build on AIX 4 by now BTW -- but I'm working on it.) I've built many mod_perl applications on linux and moved them to AIX 4.3.3 with no detriment at all. What do you mean by strangely slow? BIll
Re: AIX perfomance
On 9/12/03 at 2:54 PM, [EMAIL PROTECTED] (Ged Haywood) wrote:
Benchmarking simple CPU-intensive perl scripts shows that they
tend to be consistently slower in user time on AIX.
Assuming that the boxes aren't otherwise heavily loaded, I wonder
about the options used to compile your Perl. For x86 architecture,
things like -mcpu=i386 will make a binary that you could run on a
steam engine but it won't be able to take advantage of the richer
instruction set on newer processors. I don't have a great deal of
experience with other modern processors, but from the gcc 3.2.3
documentation:
GCC defaults to `-maix32'
and there's a '-maix64' that may be worth a look, along with the rest
of the section ('info gcc' if you have it).
Optimisation may also be an issue, but use caution. Many packages
(e.g. the Linux kernel sources :) warn against anything more than
using -O2 with gcc for example.
I think it's pretty useless to speculate as to causes until he clarifies what
strangely slow means and what AIX and linux hardware he's comparing. I've got
a lot of experience with mod_perl on both linux and AIX and can state
categorically that there are no typical conditions which would cause AIX run
strangely slowly compared to linux on comparable hardware.
Bill
