Lets explain how to configure Apache MySQL authentication. We will suppose apache web server is already up and running on the server.
First we need to install auth_mysql module.
$ sudo aptitude search libapache2-mod-auth-mysql p libapache2-mod-auth-mysql - Apache 2 module for MySQL authentication $ sudo aptitude install libapache2-mod-auth-mysql
We can control the CPU frequency with the cpufrequtils package. Installation is quite easy.
$ sudo aptitude install cpufrequtils
To check to see if it’s installed.
[06:41:32] xavi@debian: ~ $ lsmod | grep -i cpu acpi_cpufreq 6796 1 cpufreq_powersave 1856 0 cpufreq_stats 3776 0 cpufreq_ondemand 6476 1 freq_table 4224 3 acpi_cpufreq,cpufreq_stats,cpufreq_ondemand cpufreq_userspace 3172 0 cpufreq_conservative 5960 0 processor 32576 4 acpi_cpufreq,thermal [06:45:26] xavi@debian: ~ $
Here is another Perl script. This one given an Apache log file will tell you the number of hits per IP. Here is the code.
#!/usr/bin/perl -w
use strict;
use diagnostics;
if( $#ARGV != 0 ){
print "Usage: ./parser.pl <logfile>\n";
exit 1; }
# Opening logfile
open FILE, "$ARGV[0]" or die $!;
# Defining variables
my @lines = <FILE>;
my @ip;
my $items = scalar(@lines);
my ($i, $value);
my %hits;
# Removing IP addresses from logfile and counting the hits per IP.
for ($i = 0; $i < $items; $i++)
{ @ip = split (/ /, $lines[$i]);
if (exists $hits{$ip[0]}) {
$hits{$ip[0]} = $hits{$ip[0]}+1;
chomp($hits{$ip[0]}); }
else { $hits{$ip[0]} = 1; }
}
# Ordering and printing the hits per IP.
foreach $value (sort {"$hits{$b}" <=> "$hits{$a}" } keys %hits)
{ print "$value made $hits{$value} hits.\n"; }
Here is an usage example.
xavi@debianserver:~/Perl$ ./parser.pl /tmp/apachelog 12.130.86.9 made 106 hits. 208.111.39.192 made 89 hits. 67.195.114.231 made 42 hits. 98.14.22.97 made 27 hits. 208.54.45.78 made 17 hits. 213.5.71.12 made 16 hits. 199.106.237.37 made 15 hits. 66.249.67.212 made 15 hits. 208.54.45.62 made 12 hits. 87.250.252.242 made 9 hits. 174.121.74.234 made 6 hits. 188.187.102.74 made 6 hits. 208.54.45.72 made 5 hits. 64.40.121.184 made 4 hits. 206.196.125.114 made 3 hits. 207.46.13.94 made 2 hits. 220.181.146.169 made 2 hits. 142.166.170.101 made 2 hits. 220.181.94.225 made 2 hits. 142.166.170.100 made 2 hits. 65.52.108.60 made 2 hits. 207.46.199.182 made 2 hits. 207.46.13.101 made 2 hits. 208.54.45.56 made 2 hits. 209.2.233.223 made 1 hits. 67.210.218.102 made 1 hits. 66.249.67.66 made 1 hits. 220.181.7.54 made 1 hits. 207.46.199.199 made 1 hits.
As usual, suggestions are always welcome.
I don’t feel like doing a long post today so I’ll do some basic MySQL. First lets change the MySQL prompt. Here is a default MySQL prompt.
mysql> use test; Database changed mysql> select now(); +---------------------+ | now() | +---------------------+ | 2010-08-17 06:41:00 | +---------------------+ 1 row in set (0.00 sec) mysql>
Pretty boring, right? Lets spice this a little bit. Type prompt mysql \u@\d> from the MySQL prompt and lets see what happens.
mysql> prompt mysql \u@\d> PROMPT set to 'mysql \u@\d>' mysql root@test> select now() \G *************************** 1. row *************************** now(): 2010-08-17 06:44:56 1 row in set (0.00 sec) mysql root@test>
What we just did is modify the MySQL prompt to show us the user and the database being used. This is much more informative than the previous MySQL prompt.
Now what if we wanted to know the uptime of the database. Pretty simple type status; and that will give us the time the database has been up.
mysql root@test>status; -------------- mysql Ver 14.12 Distrib 5.0.75, for debian-linux-gnu (i486) using readline 5.2 Connection id: 39 Current database: test Current user: root@localhost SSL: Not in use Current pager: stdout Using outfile: '' Using delimiter: ; Server version: 5.0.75-0ubuntu10.5-log (Ubuntu) Protocol version: 10 Connection: Localhost via UNIX socket Server characterset: latin1 Db characterset: latin1 Client characterset: latin1 Conn. characterset: latin1 UNIX socket: /var/run/mysqld/mysqld.sock Uptime: 10 min 54 sec Threads: 1 Questions: 125 Slow queries: 0 Opens: 34 Flush tables: 1 Open tables: 28 Queries per second avg: 0.191 -------------- mysql root@test>
If we wanted to know the running processes just type: show full processlist \G.
mysql root@test>show full processlist \G
*************************** 1. row ***************************
Id: 39
User: root
Host: localhost
db: test
Command: Query
Time: 0
State: NULL
Info: show full processlist
1 row in set (0.00 sec)
mysql root@test>
This is all. I know this is very simple stuff, but didn’t felt like doing a long and complex post. As usual suggestions are always welcome.
References:
Let’s get started with another Tomcat chapter in this blog. Tomcat comes by default with the UserDatabaseRealm which is really crappy because it reads user info from tomcat-users.xml file and a Tomcat restart is needed for the changes to take effect. This is not appropriate for a production environment so we are going to authenticate against a MySQL database instead of the tomcat-users.xml file.
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