Posts Tagged ‘change’

How to set the preferred cipher suite on Apache 2.2.x and Apache 2.4.x Reverse Proxy

Thursday, May 4th, 2017


1. Change default Apache (Reverse Proxy) SSL client cipher suite to end customer for Android Mobile applications to work

If you're a sys admin like me and you need  to support client environments with multiple Reverse Proxy Apache servers include old ones Apache version 2.2.x (with mod_ssl compiled in Apache or enabled as external module)
and for that reason a certain specific Apache Reverse Proxy certificate SSL encoding cipher default served suite change to be TLS_DHE_RSA_WITH_AES_128_CBC_SHA in order for the application to properly communicate with the server backend application then this article might help you.

There is an end user client application which is Live on a production servers some of which running on  backend WebSphere Application Servers (WAS) / SAP /  Tomcat servers and for security and logging purposes the traffic is being forwarded from the Apache Reverse Proxies (whose traffic is incoming from a roundup Load Balancers).

Here is a short background history of why cipher suite change is necessery?

The application worked fine and was used by a desktop PCs, however since recently there is an existent Android and Apple Store (iOS) mobile phone application and the Android Applications are unable to properly handle the default served Apache Reverse Proxy cipher suite and which forced the client to ask for change in the default SSL cipher suite to:


By default, the way the client lists the cipher suites within its Client Hello will influence on Apache the selection of the cipher suite used between the client and server.

The current httpd.conf in Apache is configured so the ciphers for RP client cipher suite Hello transferred between Reverse Proxy -> Client are being provided in the following order:


1.    TLS_RSA_WITH_RC4_128_MD5
2.    TLS_RSA_WITH_RC4_128_SHA

This has to be inverted so:

becomes on the place of

A very good reading that helped me achieve the task as usual was Apache's official documentation about mod_ssl see here

So to fix the SSL/TLS cipher suite default served order use SSLCipherSuite and SSLHonorCipherOrder directives.


SSLCipherSuite directive is used to specify the cipher suites enabled on the server.
To dictate also  preferred cipher suite order directive and that's why you need SSLHonorCipherOrder directive (note that this is not available for older  Apache 2.x branch), the original bug for this directive can be seen within

For Example:



SSLHonorCipherOrder On




So here is my fix for changing the Ciphersuite SSL Crypt order (notice the TLS_DHE_RSA_WITH_AES_128_CBC_SHA being given as first argument):


SSLHonorCipherOrder On

if you want also to enable TLSv1.2 certificate cipher support you can use also:

SSLProtocol -all +TLSv1.2

SSLHonorCipherOrder on


# Old Commented configuration from my httpd.conf – no RC4, 3DES allowed


Because there was also requirement for a multiple of SSL cipher encryption (to support large range of both mobile and desktop computers and operating systems the final) cipher suite configuration in httpd.conf that worked for the client looked like so:



Once this was done the customer requested HTTP cookie restriction to be added to the same virtual host.
There initial request was to:

2. Set HTTP cookie secure flag and HttpOnly on every cookie that is not being accessed from Internal website JavaScript code

To make Apache Reverse Proxy to behave that way here is the httpd.conf config added to httpd.conf

# vim httpd.conf


   #Header edit Set-Cookie ^(.*)$ $1;HttpOnly;Secure
   Header always edit Set-Cookie ^(.*)$ $1;HttpOnly;Secure

Finally an Apache restart was necessery

chmod all directories permissions only and omit files (recursively) on Linux howto

Friday, March 11th, 2016


If you mistakenly chmod-ed all files within directory full of multiple other subdirectories and files and you want to revert back and set a certain file permissions (read, wite execute) privileges only to all directories:

find /path/to/base/dir -type d -exec chmod 755 {} +

If there are too many files or directories you need to change mod use

chmod 755 $(find /path/to/base/dir -type d) chmod 644 $(find /path/to/base/dir -type f)

Above willl run evaluate $() all files searched and print them and pass them to chmod so if you have too many files / directories to change it will drastically reduce execution time.

An alternative and perhaps a better way to do it for those who don't remember by heart the chmod permission (numbers), use something like:

chmod -R u+rwX,go+rX,go-w /path

Below is arguments meaning:

    -R = recursively;
    u+rwX = Users can read, write and execute;
    go+rX = group and others can read and execute;
    go-w = group and others can't write

If like piping, a less efficient but still working way to change all directory permissions only is with:

find /path/to/base/dir -type d -print0 | xargs -0 chmod 755
find /path/to/base/dir -type f -print0 | xargs -0 chmod 644

For those who wish to automate and often do change permissions of only files or only directories it might be also nice to look at ( shell script

Tadadam 🙂


Word 2011 Check spelling for Mac OS X 2011 – Word check text in Mac OS X Office

Monday, February 29th, 2016


If you happen to be running Mac OS X powered notebook and have recently installed Microsoft Office 2011 for Mac OS because you used to migrate from a Windows PC, you will probably suprrised that your Native Language Dictionary check you used heavily on Windows might be not performing on Mac.
This was exactly the case with my wife Svetlana and as she is not a computer expert and I'm the IT support at home I had to solve it somehow.

Luckily Office 2011 for Mac OS X which I have installed earlier comes with plenty of foreign-languages such as Russian, Bulgarian, Czech, French, German, UK English, US English etc.
Proofing tools is very handy especially for people like my wife who is natively Belarusian and is in process of learning Bulgarian, thus often in need to check Bulgarian words spelling.

By Default the Check spelling on Office package was set to English, there is a quick way to change this to a certain text without changing the check-spelling default from English, the key shortcut to use is:

I. Press Mac command (key) + A – To select All text in opened document (in our case text was in Bulgarian)


Click Word window menu and:

Choose Tools→Language

and select Bulgarian (or whatever language you need check spelling for.

If you need to change the Language default for all time, again you can do it from Tools






II. The Language dialog will appear and you'll see a list of languages to choose. 


III. Next a Pop-up Dialog will ask you whether you're sure you want to change the default language to the language of choice in my case this was Russian.


That's it check spelling default will be aplpied now to Word normal template, so next time you open a document your default spelling choice will set

How to Remove Firefox TABS all time Moving Backward / Forward (Waiting) Wheel cursor – Browser and OS Wheel Ring cursor might affect hypnotically

Monday, September 7th, 2015


I've been annoying for quite a long time by the the Clockwise moving backward and Forward Wheel (Ring) on Top of browser Tabs everytime I navigate to a new Internet domain or request a resource on the Net.

I'm aware that seeing the wheel all the time move back and forward is a very bad manipulation technique that is often used in advertisements in old movies and some advertisements in the start of the video . I'm talking about the infamous backward counting technique in a Circle (it was moer commonly used in the dawn of Television) aiming to induce watchers mind into hypnotic state …


Those who have a degree in psychology or have been into marketing or human resources fields or any field involved where you have to influence the masses are already aware of the backward counting methology which has been practiced heavily by hypnosis practisioners such as Sigmund Freud, to induce any kind of hypnotic state the hypnotist always asks the object of hypnotism to watch closely into a moving back and forwards clock, often accompanied by counting backwards …

Well my Theory here is that the same techniques is well aware of those who planned Windows OS in which if you remember the Sand Clock has been substituted in Windows 7 / 8 and Windows 10 with the rotating back and foward Wheel for the reason that this aims to influence people mind to go into Alpha state from Beta state and thus make them feel more relaxed while doing stuff on the PC.

One thing to mention here is Back and Forward wheel is not only into OS level it has been heavily adopted by leading Software as a Service (SAS) UIs such as Google's and probably more importantly Youtube (have you noticed the Cycling Wheel when waiting for a Youtube movie to Load), the Wheel is also heavily incoruprated in most if not all biggest Websites on the Net. Even If you have noticed these days Google's Cycling (Waiting) Wheel is not only Cycling but has the colorful programming incorporated.


Well probably many people who use computers daily did not really realize that the Computer OS and Programs GUI Interface they're using is influencing their mind and some famous psychological methods such as color programming and hypnotic tricks could be used more or less.

In that regard as a Firefox user I decided to change tne Back and Forward Wheel with another one which will not trigger my subconsciousness / mind all the time while browing on the Net into Alpha State. As I'm not a Firefox expert and my quick research on search Engines on how to achieve changing or removing the Browser Tabs all time turning wheel did not led me to nothing positive, I've consulted the experts in #firefox.

As always the guys were helpful and pointed me out to website's Static-Throbbler CSS. I've mirrored the CSS script under a name remove-firefox-tab-wheel-script.css in case if disappears in future, below is also a paste of the script:

@namespace url(; @-moz-document url(chrome://browser/content/browser.xul) { .tab-throbber { list-style-image: url('data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABAAAAAQCAMAAAAoLQ9TAAAABGdBTUEAALGPC/xhBQAAACBjSFJNAAB6JgAAgIQAAPoAAACA6AAAdTAAAOpgAAA6mAAAF3CculE8AAAB5lBMVEUAAADMzMzr6+v////t7e1paWmYmJiampqPj4+IiIiQkJCgoKCPj49qamqQkJB2dnacnJyAgIBfX19aWlpZWVlgYGB/f399fX2Hh4eFhYWZmZlycnJaWlpjY2Nubm56enp6enptbW1XV1dxcXGbm5uAgIBiYmKenp5ra2taWlpxcXGLi4uXl5eKioqPj4+NjY1wcHBZWVlra2uYmJhiYmKBgYFbW1t1dXWSkpKEhIR6enpsbGyBgYFubm6CgoKZmZlzc3NYWFiPj4+YmJhmZmaLi4uGhoagoKC4uLi0tLSnp6eIiIhmZmafn5+RkZFcXFx1dXWZmZl8fHzt7e3////r6+uUlJRycnJbW1uQkJCHh4d4eHiKioqxsbFubm6NjY15eXlYWFiHh4dXV1d4eHiGhoZycnKvr6+JiYl4eHiGhoaOjo6MjIxxcXHq6uqjo6N5eXmVlZVzc3OcnJxfX1+JiYl7e3tra2upqamIiIiNjY1kZGReXl6YmJiOjo59fX1YWFiSkpKAgIB2dnaYmJh0dHRoaGhqamqSkpKSkpKLi4uWlpaPj49wcHBpaWlhYWGCgoKamppwcHBjY2Nubm57e3tiYmKYmJiZmZl9fX1ZWVl+fn6bm5t1dXWOjo6GhoaNjY3///+wXn5TAAAAoXRSTlMAAAAAAAYLIzM6MiENBgEII0ZzeXtzRgcBByZhe29iWFlhe2ElBwYiY3pgRzMwNkZfemIkBUZ7XzktHyAdICs3X3sMI29KLgkJCApFbSAxe2E2IAQBAzVgeTE7WjUIHTFZejp8WzIiBy5YOzM1IwMKIDVgInRKMSALKUducyINSHw6LRo2XwZjMi0vNUhgYwYHJWFuYVhuJiNGeUUjCDI6MyoACaoAAAABYktHRAMRDEzyAAABFklEQVQY02NgYGBkZWPn4OTk4ubhZWIAAj5+AUEhYRERYVExdnEJZgZGSSlpGVk5eQVFWSVlFVUmBjV1DU0tbR1dXT19A0MjYxMGNlMzcwtLK2sbWzt7B0cxJwZnURdXNxt3D08vaztvH1FfBj//gMAg92DmkFAv27DwiEiGKLPoGJtYZgaGkNi4+ITEJIao5JTUNA+gAHO6dUamYRZDtpl0Tq5XXghzaH5BYZGmH0NxiUtpWXlFuqdXXGVVdU0tQ119g3Rjk5V1c0FlS6uIIBtDm3G7iFZVR2dXd0+vYZ96PwPLhImTlCZPUZg6ZZrIpOmSjAzMEuIzZorOcnScVTN7zlw+kHeZeJ18582fv6CWjZWRgQEA0vJCZaR0FWsAAAAldEVYdGRhdGU6Y3JlYXRlADIwMTMtMDYtMjhUMDc6NDE6NDItMDY6MDC7fUviAAAAJXRFWHRkYXRlOm1vZGlmeQAyMDEzLTA2LTI4VDA3OjQxOjUxLTA2OjAwN2LpXQAAABN0RVh0U29mdHdhcmUASmFwbmcgcjExOSfos2EAAAAASUVORK5CYII=') !important; animation-name: none !important; } .tab-throbber[progress] { list-style-image: url('data:image/png;base64,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') !important; } }

To use the script you will first need to install the Stylish FF plugin, then:


1. Enable Stylish plugin and Restart firefox when prompted
2. Click on Write New Style
3. Paste above CSS script and click on Save button



Now instead of the moving wheel you will get just a circle appearing as a static image while the page is loading.

If you want to absolutely remove any circles or images and show nothing when loading, e.g. not have any mean to monitor whether page is loaded or not, but also make it easier for the eye I even finally decided to completely remove the all time moving Wheel from Firefox Tabs even the static picture out using below CSS script with Stylish:

@namespace url(; @-moz-document url(chrome://browser/content/browser.xul) { .tab-throbber { list-style-image: none !important; animation-name: none !important; } .tab-throbber[progress] { list-style-image: none !important; } }

After all even after removing the FF Tabs wheel, there is the Status being printed down the webpage, showing text based the connection status. I find this kind of page loading status much less agressive and preferrable, than the current verions Firefox 4 onwards ..

One other thing I do to prevent the annoying Windows OS default Theme wheel is to change it to the old fashioned sand clock as well as bring back the theme of Windows 7 / 8 to Classic Theme of Win 2000, as I believe this reduced the level of zoombification the PC imposes on self 🙂


Windows 7 change windows behavior like XP How to / Make Windows 7 act like XP

Tuesday, January 21st, 2014

If you haven't worked for a while with Windows (since the days when XP was standard modern OS) you might be amazed that Windows like me. You might feel pretty unconfortable to work with Windows 7's "dock style" taskbar – showing application icons instead of buttons.


People who are traditionalist like me would definitely prefer to change this stupid behavior to "Windows Classic". Here is how to do it:

1. Right click on any open area on taskbar and choose Properties

2. From Taskbar -> Taskbar Buttons choose (Never Combine).

Never Combine – option makes every new Window to show as a separate one instead of Grouping the Windows by application.
In some cases choosing (Combine when TaskBar) is full is nice new option, so you might want to check it out for a while and see if you can get used to it.


3. Make Windows Start menu panel look like Windows 2000 (clear up unnecessary mambo-jumbo design)
I very much like simplicity thus I don't like Microsoft's choise to make Start Menu panel look like a Christmas Tree. To revert back:

On any empty space on the Desktop press Right Mouse button (Choose Personalize); Scroll down and choose (Windows Classic theme)


That will change Windows to look normal again 🙂


Cheers 🙂

MySQL SSL Configure Howto – How to Make MySQL communication secured

Wednesday, January 15th, 2014

mysql-over-ssl-how-to-configure-logo how to configure ssl on mysql server

Recently I've been asked How to make communication to MySQL database encrypted. The question was raised by a fellow developer who works on developing a Desktop standalone application in Delphi Programming Language with DevArt an (SQL Connection Component capable to connect Delphi applications to multiple databases like MySQL, Oracle, PostgreSQL, Interbase, Firebird etc.

Communicating in Secured form to MySQL database is not common task to do, as MySQL usually communicates to applications hosted on same server or applications to communicate to MySQL are in secured DMZ or administrated via phpMyAdmin web interface.

MySQL supports encrypted connections to itself using Secure Socket Layer (SSL) encryption. Setting up MySQL db to be communicated encrypted is a must for standalone Desktop applications which has to extract / insert data via remote SQL.
Configuring SQL to support communicated queries encrpytion is supported by default and easily configured on most standard Linux version distributions (Debian, RHEL, Fedora) with no need to recompile it.
1. Generate SSL Certificates

$ mkdir /etc/mysql-ssl && cd mysql-ssl

# Create CA certificate
$ openssl genrsa 2048 > ca-key.pem
$ openssl req -new -x509 -nodes -days 3600 \
         -key ca-key.pem -out ca-cert.pem

Create server certificate, remove passphrase, and sign it
server-cert.pem is public key, server-key.pem is private key
$ openssl req -newkey rsa:2048 -days 3600 \
         -nodes -keyout server-key.pem -out server-req.pem

$ openssl rsa -in server-key.pem -out server-key.pem
$ openssl x509 -req -in server-req.pem -days 3600 \
         -CA ca-cert.pem -CAkey ca-key.pem -set_serial 01 -out server-cert.pem

Create client certificate, remove passphrase, and sign it
client-cert.pem is public key and client-key.pem is private key
$ openssl req -newkey rsa:2048 -days 3600 \
         -nodes -keyout client-key.pem -out client-req.pem

$ openssl rsa -in client-key.pem -out client-key.pem
$ openssl x509 -req -in client-req.pem -days 3600 \
         -CA ca-cert.pem -CAkey ca-key.pem -set_serial 01 -out client-cert.pem

After generating the certificates, verify them:

$ openssl verify -CAfile ca-cert.pem server-cert.pem client-cert.pem

2. Add SSL support variables to my.cnf

Once SSL key pair files are generated in order to active SSL encryption support in MySQL server, add to (/etc/my.cnf,  /etc/mysql/my.cnf, /usr/local/etc/my.cnf … ) or wherever config is depending on distro


3. Restart MySQL server

/etc/init.d/mysqld restart

4. Create SQL user to require SSL login

Create new user with access to database;

GRANT ALL ON Sql_User_DB.* TO Sql_User@localhost;

To create administrator privileges user:


5. Test SSL Connection with MySQL CLI client or with few lines of PHP

To use mysql cli for testing whether SSL connection works:

$ mysql -u ssluser -p'pass' –ssl-ca /etc/mysql-ssl/client-cert.pem –ssl-cert /etc/mysql-ssl/client-key.pem

Once connected to MySQL to verify SSL connection works fine:

mysql> SHOW STATUS LIKE 'Ssl_Cipher';
| Variable_name | Value              |
| Ssl_cipher    | DHE-RSA-AES256-SHA |

If you get this output this means MySQL SSL Connection is working as should.

Alternative way is to use test-mysqli-ssl.php script to test availability to mysql over SSL.

mysqli_ssl_set($conn, '/etc/mysql-ssl/client-key.pem', '/etc/mysql-ssl/client-cert.pem', NULL, NULL, NULL);
if (!mysqli_real_connect($conn, '', 'ssluser', 'pass')) { die(); }
$res = mysqli_query($conn, 'SHOW STATUS like "Ssl_cipher"');

Note: Change username password according to your user / pass before using the script

That's all now you have mysql communicating queries data over SSL


How to change order of network cards eth0 and eth0 (swap lan cards) on Debian GNU / Linux

Friday, September 21st, 2012

Swap eth0 and eth1 lan card / how to change network card order on Debian Gnu / linux

I have a Debian server with 2 network adapter cards – (eth0 and eth1). The first lan card eth0 is Mainboard embedded (integrated) one.

The hardware of the Lenovo ThinkCentre host was purchased with one LAN Card but a second one was added in order to make the machine capable of doing NAT routing with iptables.

The machine is to be configured as a router in 1st lan card eth0, an internet UTP cable should influx and the 2nd lan card is to be connected to a Network Switch and will be used to NAT network traffic from the internal network of number of hosts with assigned local IP addresses like ( – 255) etc.

Everyone knows that integrated Network cards, are usually inferior to the normal non-integrated ones and besides that if a high voltage (during Weather Storm) enters through UTP cable attached to the integrated LAN Card it is quite likely the whole Mainboard to burn out …

With saying this back to my case I had to make the Internet to connect on eth0 on a Debian Linux host which was supposed to run as a Network router. As eth0 was the one where I had to configure the Internet real IP address to be assigned, I preferred eth0 to be attached to the non-integrated Ethernet Card which was automatically recognized and assigned to be eth1 by kernel.

Therefore I needed to swap interfaces eth0 and eth1, here is how this is done on Debian GNU / Linux Squeeze (6.0.5):

1. Edit /etc/udev/rules.d/70-persistent-net.rules

# vim /etc/udev/rules.d/70-persistent-net.rules

The file content should look something similar to:

# This file was automatically generated by the
# program, run by the persistent-net-generator.rules rules file.
# You can modify it, as long as you keep each rule on a single
# line, and change only the value of the NAME= key.
# PCI device 0x10ec:0x8168 (r8169)
SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*",
ATTR{address}=="90:f6:C2:3d:76:f5", ATTR{dev_id}=="0x0",
ATTR{type}=="1", KERNEL=="eth*", NAME="eth0"
# PCI device 0x10ec:0x8168 (r8169)
SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*",

ATTR{address}=="8d:89:a5:c2:e8:f8", ATTR{dev_id}=="0x0",

ATTR{type}=="1", KERNEL=="eth*", NAME="eth1"

Swap eth0 and eth1 definitions so eth0 becomes eth1 and vice versa, e.g.:

SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*",

ATTR{address}=="8d:89:a5:c2:e8:f8", ATTR{dev_id}=="0x0",

ATTR{type}=="1", KERNEL=="eth*", NAME="eth0"
SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*",
ATTR{address}=="90:f6:C2:3d:76:f5", ATTR{dev_id}=="0x0",
ATTR{type}=="1", KERNEL=="eth*", NAME="eth1"

ATTR{type}=="1", KERNEL=="eth*", NAME="eth0"

To make udevd, reassign eth0 / eth1 cards orders restart udev daemon:

# /etc/init.d/udev restart

or restart the system, i.e.

# restart

That should swap the Lan card order as recognized by Linux. Cheers 😉

Change default new created Debian users insecure (all users read) permissons to secure

Tuesday, September 11th, 2012

In older versions of Debian, the directory permnissions of /home/ directory used to be secure. As of time of writing this post in Debian GNU / Linux Squeeze (6.0.5), default permissions are set to such, that all permissions are set readable for all users. e.g.:

debian:~$ ls -al /home/test
drwxr-xr-x 3 test test 4096 Jul 24 10:51 test

This kind of permissions are probably set like this because of Apache configuration to display every user custom file content in web via /home/[users]/public_html through … (whatever) ~username.

This is great for machines which are supposed to be used for hosting, but for mail server or SQL Database host such permissions of new created users is quite insecure practice. Also such a /home directory settings are not good even for Webserver hosting servers, which did not display any web content via /home/ users directories.

Therefore on each new configured Debian server it is a wonderful practice to change default new created user to only readable, writable and executable by the user itself ….

To do so;

1. Edit /etc/adduser.conf

Change the variable:




This will not affect the permissions of current existing directories in /home/, i.e. /home/user1 , /home/user2 etc. but any new created one with adduser or useradd cmd will get permissions of 700

Here are permissions of recent created user syrma:

debian:~# useradd syrma
debian:~# ls -ld /home/syrma
drwxr-xr-x 98 syrma syrma 12288 7 ceâ—ˆ 13,56 hipo/

In /etc/adduserconf, there are plenty of other useful options, you might want to tune (depending on the type of new configured server). Few worthy to change sometimes are:

FIRST_UID=1000, LAST_UID=29999
FIRST_GID=1000, LAST_GID=29999

This two controls how the USER IDSs (UID) and GROUP IDs (GID)s will get assigned. In some cases it might be useful to assign new users from 1000 onwards.

Another helpful variable to tune for creating new users from there is DSHELL, on Linux defaulting to DSHELL=bash shell.

If there is a necessity to set a GLOBAL new created user quota, this is easily done also via adduser.conf. The file allows you to disable certain strings in username from present in new user logins, configure if new users will have their separate directory or belong to a system wide (user group – like in Slackware) and few others. I suggest anyone new to Linux who hears it for a first time check it.

It is maybe worthy to mention in present moment on Ubuntu Linux, by default /etc/adduser.conf, DIR_HOME=700 (is restrictive).
For some new users, who try to configure Apache read /home/[user_dir]/public_html. This could lead to unexplainable errors like:

[Tue Sep 11 10:20:17 2012] [crit] [client] (13) Permission denied:/home/syrma/.htaccess pcfg_openfile: unable to check htaccess file, ensure it is readable

This error is due to /home/syrma, improper permissions (Apache) server user (www-data) fails to read /home/syrma directory content and the Apache forked child exits with the respective error.log critical err.

If you get some errors like this, the fix is to just make the directory with readable and executable flag for all users:

# chmod -R 0755 /home/syrma

Script to Automatically change current MySQL server in wp-config.php to another MySQL host to minimize WordPress and Joomla downtimes

Friday, July 20th, 2012

I'm running a two servers for a couple of home hosted websites. One of the servers is serving as Apache host1 and has configured MySQL running on it and the second is used just for database host2 – (has another MySQL configured on it).
The MySQL servers are not configured to run as a MySQL MASTER and MySQL SLAVE (no mysql replication), however periodically (daily), I have a tiny shell script that is actualizing the data from the active SQL host2 server to host1.

Sometimes due to electricity problems or CPU overheats the active MySQL host at host2 gets stoned and stops working causing the 2 WordPress based websites and One joomla site inaccessible.
Until I manually get to the machine and restart host2 the 3 sites are down from the net and as you can imagine this has a very negative impact on the existing website indexing (PageRank) in Google.

When I'm at home, this is not a problem as I have physical access to the servers and if somethings gets messy I fix it quickly. The problem comes, whether I'm travelling or in another city far from home and there is no-one at home to give the hanged host hard reboot ….

Lately the problems with hang-ups of host2 happaned 3 times or so for 2 weeks, as a result the websites were inaccessible for hours and since there is nobody to reboot the server for hours; the websites keep hanging until the DB host is restarted ;;;;

To work-around this I came with the idea to write a tiny shell script to check if host2 is ping-able in order to assure the Database host is not down and then if script determines host2 (mysql) host is down it changes wp-config.php (set to use host2) to a wp-config.php (which I have beforehand configured to use) host1.

Using the script is a temporary solution, since I have to actually find the real hang-up causing troubles, but at least it saves me long downtimes. Here is a download link to the script I called .
I've configured the script to be run on the Apache node (host1) via a crontab calling the script every 10 minutes, here is the crontab:

*/10 * * * * /usr/sbin/ > /dev/null 2>&1

The script is written in a way so if it determins host2 is reachable a copy of wp-config.php and Joomla's configuration.php tuned to use host2 is copied over the file config originals. In order to use the script one has to configured the head variables script section, e.g.:


You will have to manually prepare;;;

wp-config-localhost.php, wp-config- ,configuration-, wp-config-localhost.php to be existing files configured to with proper host1 and host2 IP addresses.
Hope the script will be useful to others, experiencing database downtimes with WordPress or Joomla installs.