A site called “PlentyOfFish.com” is currently getting 30 million hits a day. The number doesn’t blow me off. However, what surprise me is that this site is basically operated by single man “Markus Frind”. How does he achieved that? If you want to hear how he does that, you can go to his interview from [...]

Continue reading " Plenty of Fish - Cash cow! "

Introduction of Lucene
I have heard of Lucene and its powerful full text search capability many times. Today, I decide to take a look at it. Before I dive into the user guide, I went to Google Tech Talk to find a video related to Lucene first. Here is what I found: 

After I finished this video, [...]

Continue reading " Powerful Full Text Search Engine - Part 1 Lucene Introduction "

Most companies I have worked for use Tomcat as Servlet Container. It is de facto standard just like how Apache been used as Web Server. However, most of us just drag our war file to the webapp folder and use Tomcat with all the settings as default out of the box. It works fine in [...]

Continue reading " Tomcat Performance Tuning "

If you have a file of records, and you want to find out which record(s) meets the criteria like field1=xyz, field2=abc… How would you approach it? Simple! Load the file to database, write a sql with where clause and have the database taken care of it for you. Is it the simplest way? May not! [...]

Continue reading " Power of awk "

Today, I have come across a technical issue that a process is taking too long to download a file from one of our file server. The reason is due to the number of the files of a folder is increased over time and finally reach to ~ 12000. If you use ftp, you need to [...]

Continue reading " WebDav vs FTP "

What should we look at for a machine?

CPU (how many core, how many physical cpu(s), how fast, 64 bits?, cache size)
Memory RAM
IO speed 

Dual-core CPU vs multiprocessor
A dual-core CPU is a CPU with two separate cores on the same die, each with its own cache. It’s the equivalent of getting two microprocessors in one. Multi-processor has 2 or [...]

Continue reading " Basic hardware knowledge "

Configure Tomcat

Change port to 80. 

Edit install_dir/conf/server.xml and change the port attribute of the Connector element from 8080 to 80.

Turn on servlet reloading.

Edit install_dir/conf/context.xml and change <Context> to <Context reloadable=”true”>.

Change the default AJP/1.3 connector port of Tomcat.

Edit install_dir/conf/server.xml and change the value of the port attribute in the AJP/1.3 Connector element.

Access manager console.

Create a new username/password combination [...]

Continue reading " Tomcat 5.5 - Quick Notes "

I previously thought that if I pick Java for programming, I don’t need to worry about allocating and free up memory as in C++. Certainly, Java memory management does help us to minimize the chance of memory leak. However, it does not eliminate it. It is confusing right? The key is the definition of memory leak. If [...]

Continue reading " Memory leak is possible in Java "

I see Maven as an abstraction layer of build process. If you look into the available plugins it provides like reporting and test, you may see it as an infrastructure for project collaboration. Confused? OK, let me cut the crap and get into a bit of what it does. In designer perspective, Maven is a [...]

Continue reading " Use Maven for your build process "

Grep
Pattern matching against a set of files

grep [options] “pattern” [filename or wildcard]
options:

-n : show line number
-v: negative result
-l: list out the matched filenames
-i: case-insensitive
-x: exact match
-r: recursively over the directory.

grep does not support + and ? and | operators. Use egrep instead.
Regular expression for pattern (reference visits here)

/^Mary/ : beginning of the line
/Mary$/ : end of the [...]

Continue reading " Linux Commands "