Posts Tagged ‘level’

A quick and easy way to install Social Network on Linux/BSD System with Elgg

Monday, March 14th, 2011

Reading Time: 3minutes

elgg-blue-logo
I'm experimenting this days with Elgg – An Open Source Free Software GPLed Social Network which enables users to quickly create Communities.

Elgg is really easy to install and all it requires is a Linux/BSD or Windows system with PHP, MySQL and Apache installed.

Elgg is provided with dozens of nice plugins which for a short time enables individual to create fully operational Social Network like facebook.

Many people nowdays use facebook without realizing how bad facebook is how it breaks their privacy.
Facebook is actually a spy network, it stores data and pictures, likings and user behaviour of million of users around the world.
This needs to be stopped somehow, maybe if people start using the free software networks like elgg to build a mini-community which has profound interests in a certain spheres of work, life and amusement.
The evil empire of facebook will slowly start to loose it's position and the small projects networks based on Elgg and the other Free Software Social Networks which are currently available will start to rise up.
I'm currently really a novice into Elgg but I'm more convinced that the guys who develop it and contribute to it in terms of handy plugins have done really a great job.

It's ultra easy even for non professional middle level user to setup himself an Elgg install.
The installation procedure is not much harder than a simple wordpress blog or joomla based website install.
The installation of elgg takes no more than 10 to 20 minutes, the plugin installation and setup time further could take few days but in the end you have a full featured Social Network! This is really amazing.
The installation of new plugins in elgg is also fool proof / easy all you have to do to equip a newly installed elgg with plugins is to go to it's root directory and look for the mod directory. The new plugins which needs to be installed, could be directly downloaded and saved via links, elinks, lynx or even wget to the elgg installation directory.

Most of the elgg plugins comes in a form of zip files so after being installed simply executing:

server:/home/elgg/mysocialnetwork/mod# unzip walltowall.zip
....

The above cmd will for example unzip the WallToWall elgg plugin and the plugin will be further ready to be enabled via the administrator user set upped during your elgg installation.

The configurations of elgg are being accomplished via:

Administration -> Tool Administration

I should I'm still experimenting with Elgg social, until this very moment I've installed the following elgg plugins:

aaudio
akismet
artfolio
blog
bookmarks
buddytalk
captcha
categories
chat
crontrigger
custom_index
custom_profile_fields
default_widgets
diagnostics
elgg-ebuddy
embed
embedvideo
emoticons
externalpages
family
fbconnect
file
file_tree
flyers
forum
friend_request
friends
garbagecollector
groups
htmlawed
invitations
invitefriends
izap_videos
kaltura_video
lastfm
likes
logbrowser
logrotate
lucygames
members
messageboard
messages
milockergames_frameme
noscript_message
notifications
pages
polls
profile
reportedcontent
resume
river_comments
riverdashboard
riverfaces
search
siteaccess
tagcloud
theme_simpleneutral
thewire
tidypics
tidypicsExt
tinymce
twitter
twitterservice
user_contact_list
uservalidationbyemail
walltowall
weather
wp1
zaudio

One very handy feature I truly enjoy about Elgg is that it gives every user an own blog which or in other words when somebody registers in Elgg, he automatically gets a personal blog! How cool this is Yeash 😉
The Elgg photo upload plugin is also another interesting story. The photo plugin is a way better from my first impressions than facebook's buggy upload client.
Elgg also uses heavily jquery for it's various operations and the user experience feels very interactive.

Of course as with all free software things are not perfect some of the elgg plugins or (mods) as they are called are not working.
For example I couldn't make by so far the weather plugin which is supposed to report the weather.

Maybe some tweakening of the not working plugins will easily make them working. What is really important is that the Elgg basis system looks and seems to work really good and enpowers the user with a social network alternatives to the ugly facebook.

In order to experiment with Elgg and I've established a small social network targetting at University College and School Students called MockATeacher – mockateacher.com>/i>. The idea behind is to help students in their report writting by providing them with a place where they can meet other students and share files.

Some other aspects I've planned for MockATeacher is to build a small community of people who would like to share about idiot teachers, teacher stupid sayings as well as to mock the idiotic type of education that we and our children are up to in this age.
Just to close up, if you're looking for some time to spend in experimenting in an enjoyable way you definitely need to install elgg and play with it 😉

Into great depression – What is like to live in the Balkans?

Wednesday, May 18th, 2011

Reading Time: 3minutes

I'm so depressed these days that I'm trying to write something decent here but everytime I try I do stop and delete all I have written and start from scratch again.
It's terrible, I believe everyone have this days and they're so dark that even the smallest ray of light is gone somewhere…

The causes for depression are multiple, I know we're entering into the season period and that could be a factor, but truly for a long time I haven't felt that bad and I really cannot find the true cause. It's like hunting the unexplained.
Being a citizen of a countries on the balkans brings a lot of questions which cannot get answered. Why we the Balkan and more specificly most of the Orthodox Christian countries are suffering so badly and economically in constant crisis and recession?
From a material perspective Bulgaria is one of the worst countries one can live in, we the people on the balkans are chronically depressed and it really seems like a downward spiral
We've been gone through so far, when I was a child we were teached in the spirit of communism and a believe in a hard material realities.

Communism has taught us we're all fleshly brothers and we should live in groups and stick to the group, now as the democracy come it's on the contraty, we're being constantly re-taught that we should leave behind the group kind of thinking and all built from communism destroy it all and build the new society… We're told by individualist nations like USA and Western europe that the only thing for the good of a person is to (get an absolute individualistic life and only exist for the greater goodness of each ones self as individuals..

As with everything the Balkans are notable for being a very unordered place. Living here is like living in chaos…
The social security policies here are not working, the jurisdiction is working on behalf of the rich, the police force is seriously disfunctional and easily bribable. Put next to all this shit a high levels of unemployment and a lot of unhappy depressed people crawling around the streets and you get the picture …
As a normal consequence most of the young people have entered a dark ways of alcoholism and hard-core nihillism.
There are high level of people who are oriented into the new dark realities of Metal or underground music.
Each philosophy that is being put in from the west is being adopted here and being multiplied million times and mostly the bad things are being adopted and less rarely the good ones…
It's so mixed up that nobody can explain why it is happening as it is here.
I really am trying hard to convince myself for a years now that it is worthy to live here but the more I live here in Bulgaria the more I see all is getting worser than getting for good.

I wonder for how long it will go this pointless way, we the balkan people are living in ruins literally.

The only light we still have is the Church, but very sadly most people has left behind the faith and prefer to follow the fake American dream than to obey to our old ways and traditions.

Globalisation has entered in the Balkans in a full-force and is destroying our ancient culture and traditions and building the fakeness of the coca-cola culture that most of the people prefer to adore nowdays …

Bulgaria's population is mostly based of old people and we're a dying nation, if a miracle doesn't happen then we definitely will be gone.

How to connect to WiFi network using console or terminal on GNU / Linux

Wednesday, November 2nd, 2011

Reading Time: 3minutes

iwlist-screenshot-howto-connect-to-wifi-in-text-console-linux-wpasupplicant

Sometimes its useful to connect to Wireless Networks using console . The reasons for that might be many, one possible reason is to be able to debug, Wireless connection failures or simply omit the use of the many available GUI wifi connection programs.

As a first step before connecting in terminal is to look up for the wifi networks available for connection, this is done with cmd:

linux:~# iwlist wlan0 scanning
wlan0 Scan completed :
Cell 01 - Address: 00:24:01:90:8F:38
Channel:7
Frequency:2.442 GHz (Channel 7)
Quality=70/70 Signal level=-39 dBm
Encryption key:on
ESSID:"magdanoz"
Bit Rates:1 Mb/s; 2 Mb/s; 5.5 Mb/s; 11 Mb/s
Bit Rates:6 Mb/s; 9 Mb/s; 12 Mb/s; 48 Mb/s; 18 Mb/s
24 Mb/s; 36 Mb/s; 54 Mb/s
Mode:Master
Extra:tsf=000000034f5c786b
Extra: Last beacon: 68ms ago
IE: Unknown: 00086D616764616E6F7A
IE: Unknown: 010482848B96
IE: Unknown: 030107
IE: Unknown: 32080C1218602430486C
IE: Unknown: CC0700CC020000018A
IE: Unknown: CC0700CC0300000100
IE: WPA Version 1
Group Cipher : TKIP
Pairwise Ciphers (2) : TKIP CCMP
Authentication Suites (1) : PSK
IE: IEEE 802.11i/WPA2 Version 1
Group Cipher : TKIP
Pairwise Ciphers (2) : TKIP CCMP
Authentication Suites (1) : PSK
Cell 02 - Address: 00:1E:2A:60:5E:DC
Channel:1
...

To just list the ESSID s of the wifi networks:

linux:~# iwlist wlan0 scanning|grep -i 'essid'
ESSID:"magdanoz"
ESSID:"default"
ESSID:"todorov"
ESSID:"BTC-ADSL"
ESSID:"Zahari"
ESSID:"Drago"

1. Connecting to Open Wireless Network

Now from the above output it is clear 6 wifi networks are available for connection. The default wifi network from the list is an Open network (e.g. without pass). To connect to it I use cmd:

linux:~# /sbin/iwconfig wlan0 essid 'default'
linux:~# /sbin/iwconfig wlan0 key open

After connected to configure IP, Gateway and DNS from a DHCP server running on the WIFI router, dhclient cmd is used:

linux:~# /sbin/dhclient wlan0

2. Connecting to WEP 64bit / 128bit encrypted network

linux:~# /sbin/iwconfig wlan0 key 1234-5678-9101-1213

3. Connecting to WPA / WPA2 encrypted wifi network

To connect to WPA or WPA2 encrypted network its necessery to have installed wpasupplicant package. The name of the package might vary in different distributions on Debian and Ubuntu, the name of the package is wpasupplicant, on Fedora, CentOS and RHEL the package that has to be in is wpa_supplicant :
After having installed the wpa_supplicant to connect to the network with ESSID namemagdanoz , wpa_passphrase is used first:

linux:~# /usr/bin/wpa_passphrase magdanoz Secret_Wifi_Password | tee -a /etc/wpa_supplicant.conf
network={
ssid="magdanoz"
#psk="Secret_Wifi_Password"
psk=6f7590250c4496ff7bf8dd25199ac3bb5a614d4bc069975aa884bcf084da73bc
}

As you see in above command the secret password key is generated printed on the screen and then added to /etc/wpa_supplicant.conf , necessery to establish the wireless connection with wpa_supplicant with cmd:

linux:~# /sbin/wpa_supplicant wpa_supplicant -d wext -i wlan0 -c /etc/wpa_supplicant.conf -B

-d wext instructs wpa_supplicant to use (Linux wireless extension driver).
-B tells wpa_supplicant to background the connection to prevent the wireless connection to drop off, if the console / terminal from which it is launched gets closed.

In case of succesful connection with wpa_supplicant , once again IP, Gateway and DNS is configured fetching the settings from the wifi hotspot dhcp server:

linux:~# /sbin/dhclient wlan0

General information about the wireless network and info related to the established connection can be obtained with /usr/bin/iwconfig :

linux:~# /sbin/iwconfig
lo no wireless extensions.
eth0 no wireless extensions.
wlan0 IEEE 802.11abg ESSID:"magdanoz"
Mode:Managed Frequency:2.442 GHz Access Point: 00:24:00:90:8F:38
Bit Rate=54 Mb/s Tx-Power=15 dBm
Retry long limit:7 RTS thr:off Fragment thr:off
Encryption key:off
Power Management:off
Link Quality=70/70 Signal level=-39 dBm
Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0
Tx excessive retries:0 Invalid misc:0 Missed beacon:0

To configure the exact channel over which the wireless connection will be established again is done with iwconfig, for instance to configure wlan0 wifi connection established to be on wifi channel 7:

linux:~# /sbin/iwconfig wlan0 channel 11

By default iwconfig is set to automatically set the channel based on connected network ESSID , if the channel is modified to some specific number to revert it back use:

linux:~# /sbin/iwconfig wlan0 channel auto
 

The Dangers of Authority Over-Obedience

Thursday, June 28th, 2012

Reading Time: 3minutes

dangers-of-authority-over-obesity

How much and to what level should, we obey authority. And is it really that authorities in force things always the best for the masses? Well history has shown and shows again and again that being obedient to Authority is a good think only if the authority did not pass a certain borders. In second world war both Nazis and Stalinist Russian "pogroms" passed this borders. So how this came to be? How Stalin and Hitler become the totalitarian dictators they did?

By completely dis-obeying the authorities at their times. Hitler was in Jail, Stalin was membering a communist guerillas who blow up trains and did subversive activities to Tsarist Russia. Hence obviously this two evil man was against the their times authorities. The way they raise up to power was also with breaking then ruling authorities. As a result of their dis-like for the system before Nazi Germany and Communist Russia both of the dictators lived in isolation be it among communist with anarchistic anti-government ideas in Stalin's case or living inprisoned in Hitler. The later results of being exposed to this isolation become evident, when by all means they came to power. Both of them were people with enormous egos (egoists). The only think that moved both of them was their own megalomanias and desires to be controlling imitating how God controls the universe.

But the WW II killed jews and the pogroms Stalin did in Russia was not only Stalin and Hitler's fault. It was a result of one false propaganda and openly anti-christian spread ideas all around the world. This atrocities were a fruit of the huge isolation that happened in many people lifes and their detachment from faith in God, also it was a cause of a huge masses of people who obeyed the new-created communist and Nazi authorities without questioning.
True Christians at the time in both Russia and Germany tried to oppose the new ungodly totalitarian order mainly (through press), the attempt was futile.

The reason was that many people in Germany become so heavy dependent on the local authorities. That the masses did not have the guts to go to the streets and oppose the new anti-human laws edicted. In Russia, probably at least half of the people living their lived in villages and used to obey the Tsar's authority as the monarchy was a prooved working system and for many generations people lived in monarchy and knew only monarchy; also many people in Russia were lacking high level education neither were prepared to fight something as the raising communism sponsored by Westerm Europe. So Western Europe gave money to Lenin and the communists in Russia to destroy the country monarchy from within, whether Hitler took a loan from America. Just think for a while and see how ridiculous all this is … What makes the whole thing even more ridiculous was that the money for financing both Hitler and Stalin activities (including the atrocities against poor jew people)) was financed with bank money given as loans by other Jews …

All this money were loaned because of dirty profit. There were many people in the chain who could have said no and protest against loaning the money but not wanting to disobey the system they were silently helping the whole war to bloom.

Now just 67 years after thanksfully by God's grace this war has over, the world headed the same direction as before the WW II. The severe economic crisis, the isolation of large masses of individual from family, the decay of family values, the lack of community and the over-use of technology and non-direct communication. All this makes us isolated. The increased isolation makes us unable to operate normally in many cases and hence highly dependent on the social system (just see how many people in Europe are living thanks to social pension).
The social system dependence and inability to live and think out of the established governmental system puts us in a situation, where we cannot live out of the system and to always adapt to the system. For many things, we can't say NO anymore. The over-increased surveillance and people tracking that was accepted as normal not only through Europe and America continent but the whole world is a good example on how publicity of severe freedom threat is kept in secret. People who talk about their dislike for surveillance and the possible short future abuse are even nowadays considered as abnormal paranoids. Suddenly it is more and more happening that normal society concerned people are being concerned as crazy and probably the future fate of people who in anyways question the more and more totalitarian like system that is being build right before our eyes will be similar to the WW II jews extermination …

Hannah Arendt "The Dangers of Obedience"

What is wrong with todays Economy

Tuesday, April 24th, 2012

Reading Time: 4minutes

This question is a serious question imposed at this harsh crisis times. How and why did we ended in an downward spiral economy?
There are many problems which has landed us to where we are. Anyhow there few major ones which played key role.
One is the wrong mindset of CEOs that money is the only motivator for a human behavior. Even though money can be a key motivator it is just one of many factors which motivate company employees to be efficient money is not a heal-all company problems medicine.

According to latest psychological researches conducted by Human Resource Managers. What really motivates people to do what they do full heartedly is not solely money. Social contacts at work place, the level of boredom (or the absence of it), as well as the repetitiveness of tasks, and the freedom given to the individual are key motivation factors.

Nevertheless the many other factors influencing an employee's job prudictivity, money motivation continues to be a factor with a severe weight factor.

The perception held by so many company top managers the amount of money owned and the good possessing are key factors for economy growth or company development is actually an old idea which doesn't reflect todays business reality.

We have seen in the last 30 years many companies like Microsoft and Apple, who started as tiny garage companies and in a short time converted to big corporations employing thousands.

What made this companies succesful ? Was it the money? In our view Obviously NO. Multinational companies like Google and Apple Inc started with a little money capital, but a strong belief that what they do will change the world. What happened we have seen their belief to change the world came true.
In a similar way we at Cadia started with a strong core belief that Offshore Solutions are the future of payments. By pushing the offshore solutions to develop further we believe we will fulfil our mission and change the world just like so many before us did.
Why would one prefer offshore instead of a normal banks? There are two main reasons, one is the plus that your money is not tracked by a banking system and hence fresh money are entering the economy, second is the anonimity it offers.

One of our key values at Cadia is to Respect ours and our customer freedom of privacy.

Its obvious that the business is failing because the shortage of company productivity, caused by the top management idea that its mainly the profit that makes a company a success.

Therefore as long as companies fail to "practice what they preach" e.g. keep to their Values and Company Mission, the situation with our economy will get surely worser. Even though efficiency is increased by the many technological innovations and possibly can be increased by increased money capital, the humans efficiency is falling because the lack of interest in company personal in their daily work.

What this actually means in practice? It means simply employees are not enumareted respectively to their work, companies are trying to cheat between each other puruing the ultimate profit without taking in consideration any established moral or religious norms and a lot more of "wrong" corporal activities which usually lies on the back.

Managers nowdays are ready to "kill and rape" for the good of their sallary rise or the company good, not considering if the effect of a certain company activity will have a long term bad infuence on society or the environment neither if the future consequence collectively will be devastating for humanity.

People on lower positions in companies are looking into managers unlawful activities and after a while, lower position employees start adopting unethical methodologies. Hence suddenly the unethical behaviour of the top management spreads like a virus to the lower levels down to the most low positioned company employees.

The world today is mostly governed by the rich and educated. To be rich anyhow as pointed in Maslows hierarcy of needs (Pyramid) the individual needs to have a Physiological needs & Safety Food, Shelter, basic financial stability existent.

What happens however is that a growing number of country citizens are unable to have a stability like pointed in the 1st two levels of Maslows Pyramid

Governments on the other handy are currenty tolerating non society concerned unethical companies, often even (anti-human) companies. By their tolerance our governments are increasing their dependency on multi national capital growing corporations. The result is a big mess, which becomes almost impossible to fix in time.

The poverty shadow which is falling on so many people today is also a factor changing the usual people mindset. Having the mind to survice in these hard days, a lot of individuals behaviour starts to change and tolerate anything without any examination if it serves a good or bad society purpose. Deception and lies are started to get perceived in humans mind as somethng natural and allowed, hence nobody cares about pursuing high ethical and moral values on individiual level.
The lack of responsibility for humanity on individual level forces governments to do a number of restrictions and police regulations to reduce the unlawfulness and deception between individuals. Increasing the restrictions doesn't change too much because on a peer person to person level the relations iniquity continues to raise.

Among the list of restrictions implied by governments to reduce money frauds is the attempt to close all companies in the Offshore Business providing anonymous money transfers. Anyhow would closing offshores and making all banking operations transperent solve or reduce economic problems? Positively no, it seems like this might help from one side another perspective however reveals that closing all offshore bank accounts would just make the Free Market non free anymore. It will make all payments tracked and carefully put into the ultimate balance sheet… ~

Adding another level of security to your shared Debian Linux webhosting server with SuPHP

Tuesday, April 7th, 2015

Reading Time: 3minutes

suphp_improve-apache-security-protect-against-virus-internal-server-infections-suphp-webserver-logo

There are plenty of security schemes and strategies you can implement if you're a Shared Web Hosting company sysadmin however probably the most vital one is to install on Apache + PHP Webserver SuPHP module.

# apt-cache show suphp-common|grep -i descrip -A 4

Description: Common files for mod suphp Suphp consists of an Apache module (mod_suphp for either Apache 1.3.x or Apache 2.x) and a setuid root binary (suphp) that is called by the Apache module to change the uid of the process executing the PHP interpreter to the owner of the php script.

So what SuPHP actuall  does is to run separateCPanel / Kloxo etc. Users with separate username and groupid permissions coinciding with the user present in /etc/passwd , /etc/shadow files existing users, thus in case if someone hacks some of the many customer sites he would be able to only write files and directories under the user with which the security breach occured.

On servers where SuPHP is not installed, all  systemusers are using the same UserID / GuID to run PHP executable scripts under separate domains Virtualhost which are coinciding with Apache (on Debian / Ubuntu  uid, gid – www-data) or on (CentOS / RHEL / Fedora etc. – user apache) so once one site is defaced  exploited by a worm all or most server websites might end up infected with a Web Virus / Worm which will be trying to exploit even more sites of a type running silently in the background.  This is very common scenarios as currently there are donezs of PHP / CSS / Javasripts / XSS vulnerability exploited on VPS and Shared hosting servers due to failure of a customer to update his own CMS  scripts / Website  (Joomla, Wordpress, Drupal etc.) and the lack of resource to regularly monitor all customer activities / websites.

Therefore installing SuPHP Apache module is essential one to install on new serverslarge hosting providers as it saves the admin a lot of headache from spreading malware across all hosted servers sites ..
Some VPS admins that are security freaks tend to also install SuPHP module together with many chrooted Apache / LiteSpeed / Nginx webservers each of which running in a separate Jailed environment.

Of course using SuPHP besides giving a improved security layer to the webserver has its downsides such as increased load for the server and making Apache PHP scripts being interpretted a little bit slower than with plain Apache + PHP but performance difference while running a site on top of SuPHP is often not so drastic so you can live it up ..

Installing SuPHP on a Debian / Ubuntu servers is a piece of cake, just run the as root superuser, usual:
 

# apt-get install libapache2-mod-suphp


Once installed only thing to make is to turn off default installed Apache PHP module (without SuPHP compiled support and restart Apache webserver):
 

# a2dismod php5 …

# /etc/init.d/apache2 restart


To test the SuPHP is properly working on the Apache Webserver go into some of many hosted server websites DocumentRoot

And create new file called test_suphp.php with below content:

# vim test_suphp.php
<?php
system('id');
?>

Then open in browser http://whatever-website/test_suphp.php assuming that system(); function is not disabled for security reasons in php.iniyou should get an User ID, GroupID bigger than reserved system IDs on GNU / Linux e.g. ID > UID / GID 99

Its also a good idea to take a look into SuPHP configuration file /etc/suphp/suphp.conf and tailor options according to your liking 

If different hosted client users home directories are into /home directory, set in suphp.conf

;Path all scripts have to be in

docroot=/home/


Also usually it is a good idea to set 

umask=0022 

Auto restart Apache on High server load (bash shell script) – Fixing Apache server temporal overload issues

Saturday, March 24th, 2012

Reading Time: 4minutes

auto-restart-apache-on-high-load-bash-shell-script-fixing-apache-temporal-overload-issues

I've written a tiny script to check and restart, Apache if the server encounters, extremely high load avarage like for instance more than (>25). Below is an example of a server reaching a very high load avarage:;

server~:# uptime
13:46:59 up 2 days, 18:54, 1 user, load average: 58.09, 59.08, 60.05
load average: 0.09, 0.08, 0.08

Sometimes high load avarage is not a problem, as the server might have a very powerful hardware. A high load numbers is not always an indicator for a serious problems. Some 16 CPU dual core (2.18 Ghz) machine with 16GB of ram could probably work normally with a high load avarage like in the example. Anyhow as most servers are not so powerful having such a high load avarage, makes the machine hardly do its job routine.

In my specific, case one of our Debian Linux servers is periodically reaching to a very high load level numbers. When this happens the Apache webserver is often incapable to serve its incoming requests and starts lagging for clients. The only work-around is to stop the Apache server for a couple of seconds (10 or 20 seconds) and then start it again once the load avarage has dropped to less than "3".

If this temporary fix is not applied on time, the server load gets increased exponentially until all the server services (ssh, ftp … whatever) stop responding normally to requests and the server completely hangs …

Often this server overloads, are occuring at night time so I'm not logged in on the server and one such unexpected overload makes the server unreachable for hours.
To get around the sudden high periodic load avarage server increase, I've written a tiny bash script to monitor, the server load avarage and initiate an Apache server stop and start with a few seconds delay in between.

#!/bin/sh
# script to check server for extremely high load and restart Apache if the condition is matched
check=`cat /proc/loadavg | sed 's/\./ /' | awk '{print $1}'`
# define max load avarage when script is triggered
max_load='25'
# log file
high_load_log='/var/log/apache_high_load_restart.log';
# location of inidex.php to overwrite with temporary message
index_php_loc='/home/site/www/index.php';
# location to Apache init script
apache_init='/etc/init.d/apache2';
#
site_maintenance_msg="Site Maintenance in progress - We will be back online in a minute";
if [ $check -gt "$max_load" ]; then>
#25 is load average on 5 minutes
cp -rpf $index_php_loc $index_php_loc.bak_ap
echo "$site_maintenance_msg" > $index_php_loc
sleep 15;
if [ $check -gt "$max_load" ]; then
$apache_init stop
sleep 5;
$apache_init restart
echo "$(date) : Apache Restart due to excessive load | $check |" >> $high_load_log;
cp -rpf $index_php_loc.bak_ap $index_php_loc
fi
fi

The idea of the script is partially based on a forum thread – Auto Restart Apache on High Loadhttp://www.webhostingtalk.com/showthread.php?t=971304Here is a link to my restart_apache_on_high_load.sh script

The script is written in a way that it makes two "if" condition check ups, to assure 100% there is a constant high load avarage and not just a temporal 5 seconds load avarage jump. Once the first if is matched, the script first tries to reduce the server load by overwritting a the index.php, index.html script of the website with a one stating the server is ongoing a maintenance operations.
Temporary stopping the index page, often reduces the load in 10 seconds of time, so the second if case is not necessery at all. Sometimes, however this first "if" condition cannot decrease enough the load and the server load continues to stay too high, then the script second if comes to play and makes apache to be completely stopped via Apache init script do 2 secs delay and launch the apache server again.

The script also logs about, the load avarage encountered, while the server was overloaded and Apache webserver was restarted, so later I can check what time the server overload occured.
To make the script periodically run, I've scheduled the script to launch every 5 minutes as a cron job with the following cron:

# restart Apache if load is higher than 25
*/5 * * * * /usr/sbin/restart_apache_on_high_load.sh >/dev/null 2>&1

I have also another system which is running FreeBSD 7_2, which is having the same overload server problems as with the Linux host.
Copying the auto restart apache on high load script on FreeBSD didn't work out of the box. So I rewrote a little chunk of the script to make it running on the FreeBSD host. Hence, if you would like to auto restart Apache or any other service on FreeBSD server get /usr/sbin/restart_apache_on_high_load_freebsd.sh my script and set it on cron on your BSD.

This script is just a temporary work around, however as its obvious that the frequency of the high overload will be rising with time and we will need to buy new server hardware to solve permanently the issues, anyways, until this happens the script does a great job 🙂

I'm aware there is also alternative way to auto restart Apache webserver on high server loads through using monit utility for monitoring services on a Unix system. However as I didn't wanted to bother to run extra services in the background I decided to rather use the up presented script.

Interesting info to know is Apache module mod_overload exists – which can be used for checking load average. Using this module once load avarage is over a certain number apache can stop in its preforked processes current serving request, I've never tested it myself so I don't know how usable it is. As of time of writting it is in early stage version 0.2.2
If someone, have tried it and is happy with it on a busy hosting servers, please share with me if it is stable enough?

How to enable output compression (gzipfile content compression) in nginx webserver

Friday, April 8th, 2011

Reading Time: 2minutes
I have recently installed and configured a Debian Linux server with nginx
. Since then I’ve been testing around different ways to optimize the nginx performance.

In my nginx quest, one of the most crucial settings which dramatically improved the end client performance was enabling the so called output compression which in Apache based servers is also known as content gzip compression .
In Apache webservers the content gzip compression is provided by a server module called mod_deflate .

The output compression nginx settings saves a lot of bandwidth and though it adds up a bit more load to the server, the plain text files like html, xml, js and css’s download time reduces drasticly as they’re streamed to the browser in gzip compressed format.
This little improvement in download speed also does impact the overall end user browser experience and therefore improves the browsing speed experience with websites.

If you have already had experience nginx you already know it is a bit fastidious and you have to be very careful with it’s configuration, however thanksfully enabling the gzip compression was actually rather easier than I thought.

Here is what I added in my nginx config to enable output compression:

## Compression
gzip on;
gzip_buffers 16 8k;
gzip_comp_level 9;
gzip_http_version 1.1;
gzip_min_length 0;
gzip_vary on;

Important note here is that need to add this code in the nginx configuration block starting with:

http {
....
## Compression
gzip on;
gzip_buffers 16 8k;
gzip_comp_level 9;
gzip_http_version 1.1;
gzip_min_length 0;
gzip_vary on;

In order to load the gzip output compression as a next step you need to restart the nginx server, either by it’s init script if you use one or by killing the old nginx server instances and starting up the nginx server binary again:
I personally use an init script, so restarting nginx for me is done via the cmd:

debian:~# /etc/init.d/nginx restart
Restarting nginx: nginx.

Now to test if the output gzip compression is enabled for nginx, you can simply use telnet

hipo@linux:~$ telnet your-nginx-webserver-domain.com 80
Escape character is '^]'.

After the Escape character is set ‘^]’ appears on your screen type in the blank space:

HEAD / HTTP/1.0

and press enter twice.
The output which should follow should look like:


HTTP/1.1 200 OK
Server: nginx
Date: Fri, 08 Apr 2011 12:04:43 GMT
Content-Type: text/html
Content-Length: 13
Last-Modified: Tue, 22 Mar 2011 15:04:26 GMT
Connection: close
Vary: Accept-Encoding
Expires: Fri, 15 Apr 2011 12:04:43 GMT
Cache-Control: max-age=604800
Accept-Ranges: bytes

The whole transaction with telnet command issued and the nginx webserver output should look like so:

hipo@linux:~$ telnet your-nginx-webserver-domain.com 80
Trying xxx.xxx.xxx.xxx...
Connected to your-nginx-webserver-domain.com
.Escape character is '^]'.
HEAD / HTTP/1.0

HTTP/1.1 200 OK
Server: nginx
Date: Fri, 08 Apr 2011 12:04:43 GMT
Content-Type: text/html
Content-Length: 13
Last-Modified: Tue, 22 Mar 2011 15:04:26 GMT
Connection: close
Vary: Accept-Encoding
Expires: Fri, 15 Apr 2011 12:04:43 GMT
Cache-Control: max-age=604800
Accept-Ranges: bytes

The important message in the returned output which confirms your nginx output compression is properly configured is:

Vary: Accept-Encoding

If this message is returned by your nginx server, this means your nginx now will distribute it’s content to it’s clients in compressed format and apart from the browsing boost a lot of server and client bandwitdth will be saved.

How to Turn Off, Suppress PHP Notices and Warnings – PHP error handling levels via php.ini and PHP source code

Friday, April 25th, 2014

Reading Time: 2minutes

php-logo-disable-warnings-and-notices-in-php-through-htaccess-php-ini-and-php-code

PHP Notices are common to occur after PHP version upgrades or where an obsolete PHP code is moved from Old version PHP to new version. This is common error in web software using Frameworks which have been abandoned by developers.

Having PHP Notices to appear on a webpage is pretty ugly and give a lot of information which might be used by malicious crackers to try to break your site thus it is always a good idea to disable PHP Notices. There are plenty of ways to disable PHP Notices

The easiest way to disable it is globally in all Webserver PHP library via php.ini (/etc/php.ini) open it and make sure display_errors is disabled:

display_errors = 0

or

display_errors = Off

Note that that some claim in PHP 5.3 setting display_errors to Off will not work as expected. Anyways to make sure where your loaded PHP Version display_errors is ON or OFF use phpinfo();

It is also possible to disable PHP Notices and error reporting straight from PHP code you need code like:

 

<?php
// Turn off all error reporting
error_reporting(0);
?>

 

or through code:

 

ini_set('display_errors',0);


PHP has different levels of error reporting, here is complete list of possible error handling variables:

 

 

 

<?php
// Report simple running errors

error_reporting(E_ERROR | E_WARNING | E_PARSE);

// Reporting E_NOTICE can be good too (to report uninitialized
// variables or catch variable name misspellings …)

error_reporting(E_ERROR | E_WARNING | E_PARSE | E_NOTICE);

// Report all errors except E_NOTICE
// This is the default value set in php.ini

error_reporting(E_ALL ^ E_NOTICE);
// Report all PHP errors (see changelog)

error_reporting(E_ALL);
// Report all PHP errors error_reporting(-1);
// Same as error_reporting(E_ALL);

ini_set('error_reporting', E_ALL); ?>

The level of logging could be tuned on Debian Linux via /etc/php5/apache2/php.ini or if necessary to set PHP log level in PHP CLI through/etc/php5/cli/php.ini with:

error_reporting = E_ALL & ~E_NOTICE

 

If you need to remove to remove exact warning or notices from PHP without changing the way  PHPLib behaves is to set @ infront of variable or function that is causing NOTICES or WARNING:
For example:
 

@yourFunctionHere();
@var = …;


Its also possible toDisable PHP Notices and Warningsusing .htaccess file (useful in shared hosting where you don't have access to global php.ini), here is how:

# PHP error handling for development servers
php_flag display_startup_errors off
php_flag display_errors off
php_flag html_errors off
php_flag log_errors on
php_flag ignore_repeated_errors off
php_flag ignore_repeated_source off
php_flag report_memleaks on
php_flag track_errors on
php_value docref_root 0
php_value docref_ext 0
php_value error_log /home/path/public_html/domain/php_errors.log
php_value error_reporting -1
php_value log_errors_max_len 0

This way though PHP Notices and Warnings will be suppressed errors will get logged into php_error.log

What is IPMI (IPKVM), ILO and IDRAC – Remote management interfaces to server / PC on BIOS level

Friday, May 30th, 2014

Reading Time: 3minutes

IPMI-Block-Diagram-ILO-IPKVM-how-it-works
IPMI
Intelligent Platform Management Interface is a standardized computer interface also accessible remotely via Java applet allowing remote management and monitoring access to PC BIOS. IPMI is a way to manage a computer that may be powered off or otherwise unresponsive by using a network connection to the hardware rather than to an operating system or a keyboard physical / screen login shell. The IPMI server standard was introduced by Intel and nowadays supported by more than 200 computer vendors i.e. – Super Micro, Hewlett Packard, Cisco, Dell etc.

Intelligent Platform Management Interface is an open, industry-standard interface that was designed for the management of server systems over network. IPMI interfaces by various vendors have also Virtual Media support (i.e. – Operating System  ISO files could be mounted remotely to a Virtual CD / DVD rom and you can approach installing a bare-metal server without physical presense to it). Just like Power Off / Restart, BIOS Entrance andVirtual Media access is done directly through a web-browser interface over the network or the internet.

HP_IPMI_ILO-screenshot-remote-management-server-console

ILO – stands for Integrated Lights-Out and is  HP Proliant servers remote console to PC / server physical screen. ILO is server integrated chip on HP servers and doesn't need further installations. It gives you a web console using Java showing you server screen just like there is a Monitor connected to the server it is precious for remote system administration purposes as often when there is no SSH  or Remote Desktop to server you can see directly whether the server has completed hanged and try to recover or see a failing hardware notification on the screen to a server with a partially accessible services. Using ILO console access to an HP server one can have a BIOS access remotely to machines already colocated in data canters. In other words ILO is HP's variation of IPMI remote interface also known under business buzz word IPKVM.

DRAC-Dell-Remote-Acccess-console-IPMI-tools-remote-management-bios-interface

DRAC (iDRAC)- Dell's Remote Access Controller is interface card from Dell Inc. offering remote access (out-of-band) management facilities – i.e. DRAC is Dell's variant of HP's ILO – an implementation of Intel's IPMI out-of-band standard. DRAC is also giving you remote way to access no other means accessible server on a software level. Interesting and nice things is Dell provides their DRAC source code, so if you're a developer you can learn how DRAC technology works on a lower level.

ILO, iDRAC (Dell's new generation DRAC for Blade servers) and ILO's remote management interfaces's (IPMI tools) most valuable features is it allows remote systemPower On / Shutdown and Remote Restart while monitoring the server screen (hardware output) messages and allowing you see critical hardware issue messages on pre-OS boot time, failure with memory, hard disks etc. and remote interface to do BIOS tuning.