Hardware: Router interface

Configure "DMZ" - to allow outside access(via public ip) to local machine

MySQL: MySQL Privileges needed for SELECT ... INTO OUTFILE

MySQL "FILE" Privilege is need to grant to the user, to execute SELECT ...INTO OUTFILE ..  

or 

LOAD DATA INFILE "/tmp/xxxx.csv" INTO .... 

or else, you will get 

Access denied for user 'test'@'%'  when you run the query

Linux Administration: check the server last boot, uptime and the start up and shutdown log

1) Running "uptime" which will show you how long it has been up. You can figure out last boot from that.

2) who -b (doesn't work in some distros) will give you actual date/time of last boot.

3) last -x will show you what /var/log/wtmp recorded for shutdowns. (Note you may have to specify last -x -f /var/log/wtmp.1 or something similar to see older logs.)

 

Linux Administration: to add a linux service to boot time

Here is the command:

chkconfig --level 2345 portmap on

Reference Link:

http://www.centos.org/docs/5/html/Deployment_Guide-en-US/s1-services-chkconfig.html

Run Level Reference Link:

http://en.wikipedia.org/wiki/Runlevel

http://www.skullbox.net/init.php

MySQL Error: SQLSTATE[HY000]: General error: 3 Error writing file '/tmp/xxxx.csv' (Errcode: 28)

if you happened to see the error as following, when you are running MySQL select ... into outfile "/tmp/xxxxx.csv";

 SQLSTATE[HY000]: General error: 3 Error writing file '/tmp/xxxx.csv' (Errcode: 28)

checkout your /tmp folder space in your linux, you will find your space is not enough for the file you are going to put into /tmp folder

to check,

shell> df -h

Unable to connect to internet while connected to VPN

On the VPN connection Properties dialog, on the Network tab, select Internet Protocol (TCP/IP) then click Properties.  On the TCP/IP Properties dialog click on the Advanced button.  Make sure the check box for 'Use default gateway on remote network' is unselected.

Note that for this change to take affect you'll need to reconnect if you're already connected to the VPN.

Databases: DBMS blooming

After the success of MySQL, we can see a lots of Open Source Database blooming like mushroom after the rain. Among them are MariaDB, VoltDB, SkySQL( if not mistaken ) and etc.. etc....
but is it necessary to have all these new database create ?
why they not maybe combine their efforts to create another Better SQL database, and send the MySQL to history ??
wondering ...