Repair ALL tables in a MySQL DB schema

Here is how to do it with the help of 'information_schema' of MySQL:

select concat('repair table ', table_name, ';') from information_schema.tables where table_schema='my-db-schema-name';

Linux: Show all files modified in the last X days

> find -mtime -2 -print # where 2 is the number of days back

Adding swap space on CentOS

# login as root with
su -

# not '-' sign - important!

#allocate file: 20 GB = 20 * 1024 * 1024
dd if=/dev/zero of=/swapfile bs=1024 count=20971520

mkswap /swapfile

#set permissions:
chown root:root /swapfile
chmod 0600 /swapfile

#add immediately to OS
swapon /swapfile

# edit fstab for persistence:
vi /etc/fstab

# edit fstab by adding the following line at the end of the file:
/swapfile /swap swap defaults 0 0

# check if the swap is allocated
free -m

Increase number of open files per user

http://prefetch.net/blog/index.php/2009/07/31/increasing-the-number-of-available-file-descriptors-on-centos-and-fedora-linux-servers


$ ulimit -n
1024

$ cat /proc/sys/fs/file-max
366207

$ echo 512000 > /proc/sys/fs/file-max

$ cat /proc/sys/fs/file-max
512000

$ vi /etc/security/limits.conf

Now add a line after @student (the last user listed)

@username   -   nofile   70000


$ ulimit -n
8192

sudo: Sorry, you must have a tty to run sudo (SOLVED)

I found that running a cron job on CentOS I am getting an error:
sudo: Sorry, you must have a tty to run sudo
the script, running not as a root user was using a sudo command.

Some googling showed that this is what I need (run sudo visudo to edit the config file):
Defaults requiretty
Defaults:root !requiretty
Defaults:myusername !requiretty


Thus the default remains "requiretty" for everyone but for the named users.

Installing RabbitMQ on CentOS, Fedora and RHEL

# Login as root. Note "-" in su command, it is important to get proper shell definitions including the PATH
su -
....enter password


#verify OS version
cat /etc/*release*

# Download and enable EPEL
# for CentOS 5:

# rpm -Uvh http://download.fedoraproject.org/pub/epel/5/i386/epel-release-5-4.noarch.rpm

# for CentOS 6:
rpm -Uvh http://download.fedoraproject.org/pub/epel/6/i386/epel-release-6-7.noarch.rpm 


#Get & install Erlang
wget -O /etc/yum.repos.d/epel-erlang.repo http://repos.fedorapeople.org/repos/peter
/erlang/epel-erlang.repo

yum install erlang

# Get RabbitMQ signing key
rpm --import http://www.rabbitmq.com/rabbitmq-signing-key-public.asc

# check for the latest version at RabbitMQ web site: http://www.rabbitmq.com/install-rpm.html
rpm -Uvh http://www.rabbitmq.com/releases/rabbitmq-server/v2.8.4/rabbitmq-server-2.8.4-1.noarch.rpm

yum install rabbitmq-server-2.8.4-1.noarch.rpm

# if this command did not work take a look what you got in online repositories:
# http://repos.fedorapeople.org/repos/peter/erlang/
# probably your RPM does not exists there
# in this case you can try using older RPM
# if you decided to do that, do teh following:
vi /etc/yum.repos.d/epel-erlang.repo

#comment line
baseurl=http://repos.fedorapeople.org/repos/peter/erlang/epel-$releasever/$basearch/

# and replace it with
baseurl=http://repos.fedorapeople.org/repos/peter/erlang/epel-5/$basearch/

# next, comment line
baseurl=http://repos.fedorapeople.org/repos/peter/erlang/epel-$releasever/SRPMS

# and replace it with
baseurl=http://repos.fedorapeople.org/repos/peter/erlang/epel-5/SRPMS

# exit vi and try again running
# yum install rabbitmq-server-2.8.4-1.noarch.rpm

# Add RabbitMQ to list of services to be started on reboot
chkconfig rabbitmq-server on

# Add RabbitMQ management plugin:
/usr/sbin/rabbitmq-plugins enable rabbitmq_management sudo

# start RabbitMQ server

service rabbitmq-server start


# point your browser to  http://[your-rabbitmq-server]:55672
# enter user name / pwd: the defaults are guest / guest

Installing InfoBright Enterprise Edition (trial) on CentOS 5.7

# create license file on InfoBright web
# download the latest Infobright RPM

> rpm -i ib-installation-file.rpm

#copy license file to IB installation
> cp iblicense-yan123_yan123-89359130-IEE.lic /usr/local/infobright

# run the DB
/etc/init.d/mysqld-ib start

# make IB service running after reboot
> chkconfig --add /etc/init.d/mysqld-ib
> chkconfig mysqld-ib on

# change IB / MySQL root pwd
/usr/local/infobright-4.0.6-x86_64/bin/mysqladmin -u root password 'new-password'

# run mysql client and grant all privileges to a user
# from another host who comes with a certain password
mysql-ib -u root -p
[enter root password on prompt]
> GRANT ALL ON *.* TO 'myuser' IDENTIFIED BY 'some-user-password';

#add remote access and other permissions for 'root' too
> GRANT ALL ON *.* TO 'root' IDENTIFIED BY 'some-root-password';