[Melbourne-pm] Mod_perl2

Daniel Pittman daniel at rimspace.net
Wed Sep 13 20:49:20 PDT 2006


Scott Penrose <scottp at dd.com.au> writes:
> On 14/09/2006, at 13:12, Andrew Speer wrote:
>> On Thu, September 14, 2006 11:35 am, Scott Penrose wrote:

[...]

> My experience with the above is you get the same memory footprint. As
> I said, it is not mod_perl, it is Perl that is large.
>
> I am amused by the 10M process too because our process are normally
> about 300MB using perl, and Java Tomcat starts at about 800MB+ - we
> have servers that one process is GB for TomCat - but it still runs at
> a few hundred hits a second. Although it is slow not because of the
> process size but because of what it is doing.

TomCat was, last time I checked, fairly misleading: the JVM was doing
all sorts of clever mapping tricks to make the garbage collection work.

It had a stupid quantity of memory mapped, but almost exclusively
sparsely used, and so mostly a "virtual" mapping that didn't have any
real backing, not even a page of zeros.

A quick check shows that the 200MB each Java instances on one of my
servers follows this trend: 200MB, of which almost nothing is actually
present.

Whee!
    Daniel
-- 
Digital Infrastructure Solutions -- making IT simple, stable and secure
Phone: 0401 155 707        email: contact at digital-infrastructure.com.au
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