Error loading MySQLdb module: No module named 'MySQLdb' while using mysql with python 3

MySQL with Django

To configure Django to access a MySQL database on Python, you need to do this in your settings file:

DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.mysql',
        'NAME': '<your_username>$<your_database_name>',
        'USER': '<your_username>',
        'PASSWORD': '<your_mysql_password>',
        'HOST': '<your_mysql_hostname>',
    }
}

But on python 3 you will get following error.

Error loading MySQLdb module: No module named MySQLdb.

For Python 3, you have to install "MySQL-for-Python-3":

MySQL-for-Python-3   can be  installed from below repository.

pip3 install --user https://github.com/davispuh/MySQL-for-Python-3/archive/1.0.tar.gz

Openstack-Keystone failing to start

If openstack-Keystone is not starting:

for eg:

 [root@* keystone]# service openstack-keystone restart

Stopping keystone:                                         [FAILED]
Starting keystone:                                         [  OK  ]
[root@* keystone]# service openstack-keystone restart
Stopping keystone:                                         [FAILED]
Starting keystone:                                         [  OK  ]

Try running keystone manually instead of as a service:

$ sudo -u keystone bash
$ HOME=/var/lib/keystone keystone-all --debug

PHP-FPM Listen On Unix Socket-Ubuntu 12.04

In the default configuration  PHP FPM is set to listen on TCP port 9000 on address 127.0.0.1. This can be changed in /etc/php5/fpm/pool.d/www.conf Edit the line " listen = 127.0.0.1:9000" and change it to something like             listen = /var/run/php5-fpm.sock.  *you can choose different location if required Make sure that file php5-fpm.sock is created automatically in "/var/run ". Dont create this file manually. Edit Nginx configs to tell it to pass requests through the unix socket rather than TCP. For that create a file at /etc/nginx/conf.d/ named php5-fpm.conf: upstream php5-fpm-sock { server unix:/var/run/php5-fpm.sock; }   After doing so, restart PHP FPM:  sudo /etc/init.d/php5-fpm restart

Installation and Configuration of MySQL Cluster NDB 7.2:

MYSQL-CLUSTER is a distributed database system with data nodes storing data and several application nodes for query execution. It is managed by special management nodes. Clients are not able to connect directly to the data nodes to fetch data, all commands must be run and executed over the application nodes.

    MySQL Cluster has one or more of several major components. A simpler example is to have 2 data nodes, 1 sql node and 1 management node. This is the most minimal setup.

Physical setup:

Node Details:

  MYSQL-MGMT-Node    

  MYSQL-SQL-Node         

  MYSQL-DataNode1        

  MYSQL-DataNode2     

Download   cluster-server package to all four nodes..

Mysql cluster-server package download URL::

  http://dev.mysql.com/downloads/file.php?id=451086

Mysql cluster-client package download:

http://dev.mysql.com/downloads/file.php?id=451084

Installation:

Data nodes:

rpm -Uhv <server-package.rpm>

SQL nodes:

rpm -Uhv <server-package.rpm>

rpm -Uhv <client-package.rpm>

Management nodes:

rpm -Uhv <server-package.rpm>

Configuration:

For  four-node Cluster, it is necessary to write four configuration files, one per node

•   Each data node or SQL node requires a my.cnf file that provides two pieces of information: a connection string that tells the node where to find the management node, and a line telling the MySQL server on this host (the machine hosting the data node) to enable the NDBCLUSTER storage engine.

·         The management node needs a config.ini file telling it how many replicas to maintain, how much memory to allocate for data and indexes on each data node, where to find the data nodes, where to save data to disk on each data node, and where to find any SQL nodes.

Configuring the data nodes and SQL nodes:

vi /etc/my.cnf

Modify  my.cnf like this:

[mysqld]

# Options for mysqld process:

ndbcluster                      # run NDB storage engine

[mysql_cluster]

# Options for MySQL Cluster processes:

ndb-connectstring=<mgmt server IP>  # location of management server

<Do this for the machines hosting data node and the SQL node.>

Configuring the management node:

shell> mkdir /var/lib/mysql-cluster

shell> cd /var/lib/mysql-cluster

shell> vi config.ini

Modify file like this:

[ndbd default]

NoOfReplicas=2    

DataMemory=80M    

IndexMemory=18M   

[tcp default]

portnumber=2202   

[ndb_mgmd]

hostname=<Mgmt nodeIP>          

datadir=/var/lib/mysql-cluster  

[ndbd]

hostname=<datanode IP>

datadir=/usr/local/mysql/data   

[ndbd]

hostname=<datanode IP>                  

datadir=/usr/local/mysql/data   

[mysqld]

hostname=<sqlnode IP>         

Startup of MySQL Cluster:

The management node should be started first, followed by the data nodes, and then finally by any SQL nodes:

Commands:

Mgmt Node:

shell> ndb_mgmd -f /var/lib/mysql-cluster/config.ini

Data Node:

shell> ndbd

Sql Node:

 shell> mysqld_safe &

All Database Backup and Restore

           To backup all  of your MySQL databases, you’ll need to use  mysqldump which comes  with mysql. If you have MySQL installed, you probably have mysqldump installed already.

To backup all databases use the following command:

 mysqldump -uroot -ppassword --all-databases > BackupDB.sql
 or
mysqldump -uroot -p --all-databases > BackupDB.sql

To restore all database use the following command:

mysql -u root -p < BackupDB.sql

Troubleshooting:

ERROR 1556 (HY000) at line 75485: You can't use locks with log tables.

Solution :

You may need to disable “--lock-tables” option on your dump statement ie –lock-tables=0 . 

mysqldump -uroot -ppassword --all-databases --lock-tables=0 > BackupDB.sql

Explanation:

   when we use “–lock-tables” option, the current table which is being backed up will be operating on “read only” mode to avoid further write operations during the time. The cached querry which containing “write’ operation will be executed later once after the table dump has been done. 

Basic commands for the Linux vi Editor

Command	Description
i	insert mode, (ESC to exit insert mode) allows text to be entered on the screen
a	Append to right mode
/word	Move to the occurrence of "word"
n	Locate the next occurrence
w	Advance to the next word
e	Advance to the next end of a word
b	Move to the previous word
3b	Move backward 3 words
yy	Copy line (then move cursor and use p to paste after current cursor line)
dd	delete line
3dd	delete 3 lines
D	Delete remainder of a line
dw	Delete word
x	Delete character
o	Open space for new line below the cursor line
O	Open a line above the cursor
CTRL-w	Move back a word in append mode
u	Undo last
U	Undo all changes to current line
.	In command mode, repeat the last text changing the command on the current line
:w newfilename	save the file to newfilename from the command mode
:wq	save and quit
:q!	quit without saving
r	replace then typa a character ot be replaced with r then return to break up a line
J	join 2 lines
s	substitute (sentence) typed text over a character, ESC when done
cw	change word
c	change part of a line from the cursor to the end of the line
cc	substitute new text for aline, ESC when done
h	move the cursor back one space
H	move the cursor to the highest line on the screen
L	move the cursor to the lowest line on the screen
M	position the cursor at the midpoint on the screen
G	last line in the file
0 (zero)	Move the cursor to the beginning of the line it is on
view filename	Open a file for viewing only
set number	Turn on line numbers
set nonumber	Turn off line numbers
Options
autoindent	(ai ctrl-d to move to the left
showmatch	match brackets and parenthesis
tabstop=4
wrapmargine(wm)	when line is wrapped (80-value)
:2 copy 4	Place a copy of line 2 after line 4.
:1,4 copy 7	(lines 1-4)
:n	Access the next file for editing

Change Windows 8 Product Key After Install.

                           Change Windows 8 Product Key After Install.

1. Launch the Start Menu and type in command prompt or cmd so that it shows up on your start menu search list. Right click on the Command Prompt shortcut and select Run As Administrator.
2. At the administrator command prompt, type in "slmgr.vbs -ipk <insert your product key here>"
   
   slmgr.vbs -ipk 00000-00000-00000-00000-00000
3. To activate windows after changing the key, run "slmgr.vbs -ato"