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Posted to modperl-cvs@perl.apache.org by pg...@apache.org on 2006/11/09 09:15:39 UTC
svn commit: r472808 - /perl/Apache-SizeLimit/trunk/README
Author: pgollucci
Date: Thu Nov 9 00:15:39 2006
New Revision: 472808
URL: http://svn.apache.org/viewvc?view=rev&rev=472808
Log:
flipping README to default of Apache2::SizeLimit documentation
which note to see Apache/SizeLimit.pm for the 1.x series.
Modified:
perl/Apache-SizeLimit/trunk/README
Modified: perl/Apache-SizeLimit/trunk/README
URL: http://svn.apache.org/viewvc/perl/Apache-SizeLimit/trunk/README?view=diff&rev=472808&r1=472807&r2=472808
==============================================================================
--- perl/Apache-SizeLimit/trunk/README (original)
+++ perl/Apache-SizeLimit/trunk/README Thu Nov 9 00:15:39 2006
@@ -1,35 +1,23 @@
NAME
- Apache::SizeLimit - Because size does matter.
+ Apache2::SizeLimit - Because size does matter.
SYNOPSIS
-
- SVN trunk should now be functional in both mp1 and mp2 series.
- HOWEVER, it has not yet been well tested.
-
- Please See:
- http://svn.apache.org/repos/asf/perl/Apache-SizeLimit/stable
- for now.
-
<Perl>
- Apache::SizeLimit->set_max_process_size(150_000); # Max size in KB
- Apache::SizeLimit->set_min_shared_size(10_000); # Min share in KB
- Apache::SizeLimit->set_max_unshared_size(120_000); # Max unshared size in KB
+ Apache2::SizeLimit->set_max_process_size(150_000); # Max size in KB
+ Apache2::SizeLimit->set_min_shared_size(10_000); # Min share in KB
+ Apache2::SizeLimit->set_max_unshared_size(120_000); # Max unshared size in KB
</Perl>
- PerlCleanupHandler Apache::SizeLimit
+ PerlCleanupHandler Apache2::SizeLimit
-DESCRIPTION
- ******************************** NOIICE *******************
+ *****************************************************************
- This version is only for httpd 1.x and mod_perl 1.x
- series.
+ For httpd 1.3.x / mod_perl 1.x Apache::SizeLimit documentation
+ please read the perldoc in lib/Apache/SizeLimit.pm
- Future versions of this module may support both.
+ ******************************************************************
- Currently, Apache2::SizeLimit is bundled with
- mod_perl 2.x for that series.
-
- ******************************** NOTICE *******************
+DESCRIPTION
This module allows you to kill off Apache httpd processes if they grow
too large. You can make the decision to kill a process based on its
@@ -48,17 +36,17 @@
API
You can set set the size limits from a Perl module or script loaded by
- Apache by calling the appropriate class method on "Apache::SizeLimit":
+ Apache by calling the appropriate class method on "Apache2::SizeLimit":
- * Apache::SizeLimit->set_max_process_size($size)
+ * Apache2::SizeLimit->set_max_process_size($size)
This sets the maximum size of the process, including both shared and
unshared memory.
- * Apache::SizeLimit->set_max_unshared_size($size)
+ * Apache2::SizeLimit->set_max_unshared_size($size)
This sets the maximum amount of *unshared* memory the process can
use.
- * Apache::SizeLimit->set_min_shared_size($size)
+ * Apache2::SizeLimit->set_min_shared_size($size)
This sets the minimum amount of shared memory the process must have.
The two methods related to shared memory size are effectively a no-op if
@@ -69,25 +57,25 @@
There are several ways to make this module actually run the code to kill
a process.
- The simplest is to make "Apache::SizeLimit" a "PerlCleanupHandler" in
+ The simplest is to make "Apache2::SizeLimit" a "PerlCleanupHandler" in
your Apache config:
- PerlCleanupHandler Apache::SizeLimit
+ PerlCleanupHandler Apache2::SizeLimit
- This will ensure that "Apache::SizeLimit->handler()" is run for all
+ This will ensure that "Apache2::SizeLimit->handler()" is run for all
requests.
If you want to combine this module with a cleanup handler of your own,
- make sure that "Apache::SizeLimit" is the last handler run:
+ make sure that "Apache2::SizeLimit" is the last handler run:
- PerlCleanupHandler Apache::SizeLimit My::CleanupHandler
+ PerlCleanupHandler Apache2::SizeLimit My::CleanupHandler
Remember, mod_perl will run stacked handlers from right to left, as
they're defined in your configuration.
If you have some cleanup code you need to run, but stacked handlers
aren't appropriate for your setup, you can also explicitly call the
- "Apache::SizeLimit->handler()" function from your own cleanup handler:
+ "Apache2::SizeLimit->handler()" function from your own cleanup handler:
package My::CleanupHandler
@@ -98,22 +86,22 @@
# request
File::Temp::cleanup();
- return Apache::SizeLimit->handler($r);
+ return Apache2::SizeLimit->handler($r);
}
- * Apache::SizeLimit->add_cleanup_handler($r)
+ * Apache2::SizeLimit->add_cleanup_handler($r)
You can call this method inside a request to run
- "Apache::SizeLimit"'s "handler()" method for just that request. It's
- safe to call this method repeatedly -- the cleanup will only be run
- once per request.
+ "Apache2::SizeLimit"'s "handler()" method for just that request.
+ It's safe to call this method repeatedly -- the cleanup will only be
+ run once per request.
Checking Every N Requests
Since checking the process size can take a few system calls on some
platforms (e.g. linux), you may not want to check the process size for
every request.
- * Apache::SizeLimit->set_check_interval($interval)
- Calling this causes "Apache::SizeLimit" to only check the process
+ * Apache2::SizeLimit->set_check_interval($interval)
+ Calling this causes "Apache2::SizeLimit" to only check the process
size every $interval requests. If you want this to affect all
processes, make sure to call this during server startup.
@@ -144,7 +132,7 @@
linux
For linux we read the process size out of /proc/self/statm. If you are
worried about performance, you can consider using
- "Apache::SizeLimit->set_check_interval()" to reduce how often this read
+ "Apache2::SizeLimit->set_check_interval()" to reduce how often this read
happens.
As of linux 2.6, /proc/self/statm does not report the amount of memory
@@ -157,31 +145,31 @@
various sizes for each memory segment of a process and allows us to
count the amount of shared memory correctly.
- If "Apache::SizeLimit" detects a kernel that supports /proc/self/smaps
+ If "Apache2::SizeLimit" detects a kernel that supports /proc/self/smaps
and the "Linux::Smaps" module is installed it will use that module
instead of /proc/self/statm.
Reading /proc/self/smaps is expensive compared to /proc/self/statm. It
must look at each page table entry of a process. Further, on
multiprocessor systems the access is synchronized with spinlocks. Again,
- you might consider using "Apache::SizeLimit->set_check_interval()".
+ you might consider using "Apache2::SizeLimit->set_check_interval()".
Copy-on-write and Shared Memory
The following example shows the effect of copy-on-write:
<Perl>
- require Apache::SizeLimit;
+ require Apache2::SizeLimit;
package X;
use strict;
- use Apache::Constants qw(OK);
+ use Apache2::Const -compile => qw(OK);
my $x = "a" x (1024*1024);
sub handler {
my $r = shift;
- my ($size, $shared) = $Apache::SizeLimit->_check_size();
+ my ($size, $shared) = $Apache2::SizeLimit->_check_size();
$x =~ tr/a/b/;
- my ($size2, $shared2) = $Apache::SizeLimit->_check_size();
+ my ($size2, $shared2) = $Apache2::SizeLimit->_check_size();
$r->content_type('text/plain');
$r->print("1: size=$size shared=$shared\n");
$r->print("2: size=$size2 shared=$shared2\n");
@@ -234,7 +222,7 @@
According to recent tests on OSX (July, 2006), "BSD::Resource" simply
reports zero for process and shared size on that platform, so OSX is not
- supported by "Apache::SizeLimit".
+ supported by "Apache2::SizeLimit".
AIX?
Uses "BSD::Resource::getrusage()" to determine process size. Not sure if
@@ -278,23 +266,38 @@
Previous versions of this module documented three globals for defining
memory size limits:
- * $Apache::SizeLimit::MAX_PROCESS_SIZE
- * $Apache::SizeLimit::MIN_SHARE_SIZE
- * $Apache::SizeLimit::MAX_UNSHARED_SIZE
- * $Apache::SizeLimit::CHECK_EVERY_N_REQUESTS
- * $Apache::SizeLimit::USE_SMAPS
+ * $Apache2::SizeLimit::MAX_PROCESS_SIZE
+ * $Apache2::SizeLimit::MIN_SHARE_SIZE
+ * $Apache2::SizeLimit::MAX_UNSHARED_SIZE
+ * $Apache2::SizeLimit::CHECK_EVERY_N_REQUESTS
+ * $Apache2::SizeLimit::USE_SMAPS
Direct use of these globals is deprecated, but will continue to work for
the foreseeable future.
It also documented three functions for use from registry scripts:
- * Apache::SizeLimit::setmax()
- * Apache::SizeLimit::setmin()
- * Apache::SizeLimit::setmax_unshared()
+ * Apache2::SizeLimit::setmax()
+ * Apache2::SizeLimit::setmin()
+ * Apache2::SizeLimit::setmax_unshared()
Besides setting the appropriate limit, these functions *also* add a
- cleanup handler to the current request.
+ cleanup handler to the current request. In the 2.x series of mod_perl to
+ use the deprecated functions, you must set PerlOptions +GlobalRequest
+ accordingly.
+
+SUPPORT
+ The Apache-SizeLimit project is co-maintained by several developers, who
+ take turns at making CPAN releases. Therefore you may find several CPAN
+ directories containing Apache-SizeLimit releases. The best way to find
+ the latest release is to use http://search.cpan.org/.
+
+ If you have a question or you want to submit a bug report or make a
+ contribution, please do not email individual authors, but send an email
+ to the modperl <at> perl.apache.org mailing list. This list is
+ moderated, so unless you are subscribed to it, your message will have to
+ be approved first by a moderator. Therefore please allow some time (up
+ to a few days) for your post to propagate to the list.
AUTHOR
Doug Bagley <do...@bagley.org>, channeling Procrustes.