The BLACKHOLE Storage Engine

The BLACKHOLE storage engine acts as a “black hole” that accepts data but throws it away and does not store it. Retrievals always return an empty result:

mysql> CREATE TABLE test(i INT, c CHAR(10)) ENGINE = BLACKHOLE;

Query OK, 0 rows affected (0.03 sec)

 

mysql> INSERT INTO test VALUES(1,’record one’),(2,’record two’);

Query OK, 2 rows affected (0.00 sec)

Records: 2  Duplicates: 0  Warnings: 0

 

mysql> SELECT * FROM test;

Empty set (0.00 sec).

The cron command

The crontab command shown below will activate the cron tasks automatically on the hour:
0 * * * * wget -O – -q -t 1 http://www.jit.co.in/cron.php

In the above sample, the 0 * * * * represents when the task should happen. The first figure represents minutes – in this case, on the “zero” minute, or top of the hour. (If the number were, say, 10, then the action would take place at 10 minutes past the hour.) The other figures represent, respectively, hour, day, month and day of the week. A * is a wildcard, meaning “every time.”

The rest of the line basically tells the server to “ping” the url http://www.jit.co.in/cron.php.
Here is a diagram of the general crontab syntax, for illustration:

# +—————- minute (0 – 59)
# | +————- hour (0 – 23)
# | | +———- day of month (1 – 31)
# | | | +——- month (1 – 12)
# | | | | +—- day of week (0 – 7) (Sunday=0 or 7)
# | | | | | * * * * * command to be executed

Add ONE of the following lines:

45 * * * * /usr/bin/lynx -source http://jit.co.in/cron.php
45 * * * * /usr/bin/wget -O – -q -t 1 http://www.jit.co.in/cron.php
45 * * * * curl –silent –compressed http://jit.co.in/cron.php.

The Three Ways to Cloud Compute

 

SAAS – Software as a Service

Best Part

  1. Accessible from anywhere through internet
  2. Good for the collaborative environment
  3. Subscription basis can save cost instead of investing a huge money
  4. Reduce Infrastructure Cost, Maintenance Cost, etc.

Need to Think

  • Genric Application sometimes not suitable for all business
  • But can be archive though customized plugin

PAAS – Platform as a Service

Provide environment and tools for creating new online application

Example: Google App Engine, Iphone IOS, Microsoft Azure Platform

Best Part

  • Rapid development at low cost
  • Private and public deployments

Need to Think

  • Limited developer to provider languages and tools
  • Risk of vendor lock-in

IAAS – Infrastructure as a Service

Allow existing applications to sun on a cloud’s hardware

Example- Shared hosting.

Project Open ]po[

Project Open
Nice Project Management Tool;
http://www.project-open.com

]po[ iPhone App available
Follows PMI Guideline
Good UI & Structuring

But
Only CVS Support! SVN Integration is on the way; no Idea on GIT Support
Instead of MySQL they use PostgreSQL.