Tag Archives: Debian

Setting replication MySQL version 5.5

So the other day I performed an upgrade of MySQL on a linode and notice that it wont start if I kept my old my.cnf file.

[11:47:06] user@linode1: ~ $ echo 'SHOW VARIABLES LIKE "%version%";' | mysql -u username -ppassword | grep innodb
innodb_version  5.5.31
[11:47:20] user@linode1: ~ $ 
131022 08:17:56 mysqld_safe Starting mysqld daemon with databases from /var/lib/mysql
131022  8:17:56 [ERROR] An old style --language value with language specific part detected: /usr/share/mysql/english/
131022  8:17:56 [ERROR] Use --lc-messages-dir without language specific part instead.
131022  8:17:56 [Note] Plugin 'FEDERATED' is disabled.
131022  8:17:56 InnoDB: The InnoDB memory heap is disabled
131022  8:17:56 InnoDB: Mutexes and rw_locks use GCC atomic builtins
131022  8:17:56 InnoDB: Compressed tables use zlib 1.2.7
131022  8:17:56 InnoDB: Using Linux native AIO
131022  8:17:56 InnoDB: Initializing buffer pool, size = 128.0M
131022  8:17:56 InnoDB: Completed initialization of buffer pool
131022  8:17:56 InnoDB: highest supported file format is Barracuda.
131022  8:17:56  InnoDB: Waiting for the background threads to start
131022  8:17:57 InnoDB: 5.5.31 started; log sequence number 1678395
131022  8:17:57 [ERROR] /usr/sbin/mysqld: unknown variable 'master-host='
131022  8:17:57 [ERROR] Aborting

Thing is the replication entries in my.cnf need to be removed/commented out and salve needs to be set up from MySQL console.

So here is my new my.cnf.

[11:34:25] xavi@linode1: ~ $ sudo grep -v “^#” /etc/mysql/my.cnf | grep -v “^$”

port            = 3306
socket          = /var/run/mysqld/mysqld.sock
socket          = /var/run/mysqld/mysqld.sock
nice            = 0
server-id       = 2
user            = mysql
pid-file        = /var/run/mysqld/mysqld.pid
socket          = /var/run/mysqld/mysqld.sock
port            = 3306
basedir         = /usr
datadir         = /var/lib/mysql
tmpdir          = /tmp
language        = /usr/share/mysql/english
bind-address            =
key_buffer              = 16M
max_allowed_packet      = 16M
thread_stack            = 128K
thread_cache_size       = 8
myisam-recover          = BACKUP
query_cache_limit       = 1M
query_cache_size        = 16M
expire_logs_days        = 10
max_binlog_size         = 100M
max_allowed_packet      = 16M
key_buffer              = 16M
!includedir /etc/mysql/conf.d/

[11:34:37] xavi@linode1: ~ $

We load the above file or similar depending on your configuration. Now to configure slave we log into the MySQL CLI.

mysql> STOP SLAVE;
mysql> CHANGE MASTER TO MASTER_HOST=’′, MASTER_USER=’replication-user’, MASTER_PASSWORD=’password’, MASTER_LOG_FILE=’mysql-bin.000747′, MASTER_LOG_POS=75797;

That’s it.

DNS records creator

Back around here. Quick post of a small script to create A and PTR dns records.

Input file. First column is the IP and second column is the fqdn. We call this file hosts.txt athletic.abc.com deportivo.abc.com drac1.abc.com

Script below:


while read line; do
        IP=`echo $line | awk '{print $1}'`
        HOST=`echo $line | awk '{print $2}'`
        PTR=`echo "${IP}" | awk -F\. '{print $4"."$3"."$2"."$1".in-addr.arpa."}'`
        echo "${HOST}. IN A ${IP}"
        echo "${PTR} IN PTR ${HOST}."
done < hosts.txt


me@server:/tmp$ bash dnsconverter.sh
athletic.abc.com. IN A IN PTR athletic.abc.com.
deportivo.abc.com. IN A IN PTR deportivo.abc.com.
drac1.abc.com. IN A IN PTR drac1.abc.com.

Project Euler problem 30

Below is the solution to problem 30 from Project Euler. It’s written in Python, a programming language I’m trying to learn.

#!/usr/bin/env python 
# Project Euler problem 30

narc_sum = 0
for number in range(100, 200000):
        # Transform the number into a string
        string = str(number)
        # Transform the string into a list
        lst = list(string)
        sum = 0 
        for i in range(len(lst)):
                # Add the members of the list to the fifth power
                sum = sum + (int(lst[i])**5)
        if (number == sum):
                # Add all numbers and store in narc_sum value
                narc_sum = narc_sum + number
                print "Sum is ",narc_sum