Stas Bekman

Before you start to optimize server configuration and learn to write a more efficient code you need to consider the demands which will be placed on the Hardware and the Operating System. There is no point in investing a lot of time and money in configuration tuning and code optimizing only to find that your […]

You want an OS with good memory sharing capabilities. If you preload the Perl modules and scripts at server startup, they are shared between the spawned children (at least for a part of a process’ life – memory pages can become ”dirty” and cease to be shared). This feature can reduce memory consumption a lot! […]

Redundant Array of Inexpensive Disks (RAID): An array of physical disks, usually treated by the operating system as one single disk, and often forced to appear that way by the hardware. The reason for using RAID is often simply to achieve a high data transfer rate, but it may also be to get adequate disk […]

So the is shared between the My::HTML package and script.pl. It will work vice versa as well, if you create the object in My::HTML but use it in script.pl. You have true sharing, since if you change in script.pl, it will be changed in My::HTML as well. What if you need to share between more […]

Now in packages that want to use the configuration variables I have either to use the fully qualified names like ::Config::test, which I dislike or import them as described in the previous section. But hey, since I have only one variable to handle, I can make things even simpler and save the loading of the […]

Now I know the module name and it’s loaded, so for example if I need to use some variables stored in this module to open a database connection, I will do: Apache::DBI->connect_on_init (“DBI:mysql:$ {.’::DB_NAME’}::$ {.’::SERVER’}”, $ {.’::USER’}, $ {.’::USER_PASSWD’}, { PrintError => 1, # warn() on errors RaiseError => 0, # don’t die on error […]

And finally I want to cover the pitfall many people has fallen into. Let’s talk about regular expressions used under mod_perl. When using a regular expression that contains an interpolated Perl variable, if it is known that the variable (or variables) will not change during the execution of the program, a standard optimization technique is […]

##################################################### # Build_MatchMany_Function # — Input: list of patterns # — Output: A code ref which matches its sh[0] # against ANY of the patterns given in the # “Input”, efficiently. # sub Build_MatchMany_Function { my @R = @_; my = join ‘||’, map { “$_[0] =~ m/$R[sh]/o” } ( 0..0R ); my = eval […]

# Register all requests ### foreach (1..) { foreach my (@urls) { my = HTTP::Request->new(‘GET’, ); ->register(); } } ### # Launch processes and check time ### my = [gettimeofday]; my = ->wait(); my = tv_interval(); ### # Requests all done, check results ### my = 0; my %errors = (); foreach my (values %) […]

This is another crashme suite originally written by Michael Schilli (and was located at http://www.linux-magazin.de site, but now the link has gone). I made a few modifications, mostly adding my() operators. I also allowed it to accept more than one url to test, since sometimes you want to test more than one script. The tool […]

http_load — another webserver Benchmarking tool http://www.acme.com/software/http_load/ Apache-Perl-contrib package http://perl.apache.org/dist/contrib/ Time::HiRes http://search.cpan.org/search?dist=Time-HiRes and Benchmark is a part of the Core Perl LWP (libwww-perl) http://search.cpan.org/search?dist=libwww-perl

Now you need to specify which processes are to be monitored. The regular expression that will match the desired processes is required for this section to work. For example if you want to see all the processes whose name include any of these strings: http, mysql and squid, the following regular expression is to be […]