Category Archives: tips

Web page load speed monitoring with Munin

Here’s an example of the configuration:

[http_loadtime]
     env.target https://pydelion.com

Enabling:

ln -s /usr/share/munin/plugins/http_loadtime /etc/munin/plugins/http_loadtime

Test run:

[root@node1 ~]# sudo munin-run http_loadtime
loadtime.value 1.04
[root@node1 ~]#

Munin restart:

[root@node1 ~]# service  munin-node restart
Stopping Munin Node agents:                                [  OK  ]
Starting Munin Node:                                       [  OK  ]
[root@node1 ~]#

If you need external check you can use pingdom tools, for instance.

How to get number of registered users in WordPress databases (if you have a lot of databases)

Task

There are a lot of WordPress based websites (as well as not WordPress) databases on your box.  It’s necessary to get  number of registered users in WordPress databases only.

Solution

Collecting WordPress databases:

mysql -Bse " use information_schema; select TABLE_SCHEMA from TABLES where table_name like 'wp_users';" > wp_users.txt

Getting the numbers:

for i in $(cat wp_users.txt ) ; do echo -n $i " "; mysql -Bse "use $i ; select count(id) from wp_users " ; echo ; done | sort -rnk2 | less

How to send a message over Jabber from Python

Sending a message over Jabber from Python is a simple task. Let’s install Python Jabber/XMPP implementation called pyxmpp2:

python-pip install pyxmpp2

Now download client example:

wget https://raw.github.com/Jajcus/pyxmpp2/master/examples/send_message_client.py

And run:

python send_message_client.py

After you enter all data a message will be sent.

How to run a script as another user (without password) on Linux

Probably, it’s one of the most common tasks: running some scripts as another user and not being root. Here’s a solution.

1. Run visudo. If you don’t have it make sure you have sudo installed.

2. Add next line:

myuser ALL=(anotheruser) NOPASSWD: /home/anotheruser/bin/script.py

3. Run:

sudo -u anotheruser /home/anotheruser/bin/script.py

How to install Java on Fedora 18 box

[root@bender ~]# yum search openjdk
Loaded plugins: security, show-leaves
============================= N/S Matched: openjdk =============================
java-1.7.0-openjdk.i686 : OpenJDK Runtime Environment
java-1.7.0-openjdk.x86_64 : OpenJDK Runtime Environment
java-1.7.0-openjdk-demo.x86_64 : OpenJDK Demos
java-1.7.0-openjdk-devel.x86_64 : OpenJDK Development Environment
java-1.7.0-openjdk-javadoc.noarch : OpenJDK API Documentation
java-1.7.0-openjdk-src.x86_64 : OpenJDK Source Bundle
thermostat.x86_64 : A monitoring and serviceability tool for OpenJDK

Name and summary matches only, use "search all" for everything.
[root@bender ~]# yum install java-1.7.0-openjdk.x86_64

This is it.