Create a site with 10s millions users

local.telenav.com has been launched

2010-03-14T23:25:00.000-07:00

the site http://local.telenav.com has been launched. It provides quickly search based on user's location.

It has 0 users since nobody knows it yet. but the target is to grow the site bigger than the yelp.com, Google local and Yahoo Local.

Stay with me about the process. give me the suggestion too.

Software Configuration Management Tools

2008-04-20T22:25:00.000-07:00

copied from http://www.software-configuration.com/software_configuration_tools.html

Software Configuration Management Tools
configuration managment system Posted by Rob Castellow

So now is the fun part. You get to pick which tools you will be using to make your development process as smooth as possible. I will attempt to give my experiences with a select few tools that I have seen be useful in a software configuration management environment. If you, the reader, know of other tools that you feel should really be mentioned, please feel free to send suggestions to my email address in the contact section.
First, let's address each area that you will need at some point of the software design life cycle...

Version Control Tools
Subversion (http://subversion.tigris.org) - This is quickly becoming the open source industry standard for version control. Subversion provides numerous features and also there is an enormous amount of support for development tools (Eclipse, NetBeans, etc) Subversion was developed by many of the original CVS developers and was designed to address all the things wrong with CVS.

Git (http://git.or.cz/) - A non-traditional SCM tool but efficient and distributed version control system. This project was originally created to manage version controlling LINUX kernels. The main push on Git is to handle large projects more efficiently.

Clearcase (http://www-306.ibm.com/software/awdtools/clearcase/) - Did I say that I was cheap? Yes, I did, but I would like to mention Clearcase anyway. First, understand the cost of Clearcase is more than what appears on your invoice. The real cost to maintain Clearcase is in maintaining a local server, and then if multi-site is needed, just multiply that cost by the number of remote locations. Other than the enormous costs, if I had to pay for a version control tool I would select Clearcase for its overall functionality.
Multi Site replicators
WANDisco (http://www.wandisco.com) - I have not personally used this product, but I know that WANDisco is the leader in providing multi site solutions for Subversion, JIRA, and CVS.
Defect and Enhancement Tracking
JIRA (http://www.atlassian.com/software/jira/) - JIRA is a customizable bug and issue tracker. JIRA provides custom workflows, web service interfaces and much more. I have used JIRA and it is extremely intuitive. JIRA is not free, but it is extremely cheap compared to other tools.

TRAC (http://trac.edgewall.org) - I use TRAC on all my home projects, and it is extremely simple and flexible. TRAC has an interface to Subversion and also has an integrated wiki. TRAC also reads wiki markup in the commit comments of Subversion. TRAC is also open source.

Bugzilla (http://www.bugzilla.org) - Bugzilla is an old standby for many developers. I would suggest though that there are many better tools out there these days. However, if you just want the old classic, Bugzilla is still actively maintained. Bugzilla is open source.

Scarab (http://scarab.tigris.org) - Scarab is an open source tool to track issues. Scarab is a Java based implementation over MySQL. Scarab is highly configurable, and will also import/export data from other defect tracking tools.

Mantis (http://www.mantisbt.org) - Mantis is a popular open source web based issue tracker. Easily installed and configurable.

Requirement Tools
OSRMT (http://sourceforge.net/projects/osrmt) - Open Source Requirements Management Tool manages features, requirements, design, implementation, and testing.

Iterative Build Tools
Cruise Control - CruiseControl was for many years on the forefront of continuous build integration. CruiseControl has been a favorite by many. There are many options to the CruiseControl tool, which can all be configured in its xml configuration file.

Hudson - A newer but powerful continuous integration build tool. I am using this tool on a project now, and enjoy Hudson's many options, nice interface, and good communication options.

Environment Management Tools
SourceForge - (http://sourceforge.net) - The world's largest open source development web site. This environment allows any open source project to host itself for free on the site. SourceForge also enables developers to communicate efficiently, track defects, and provides version control.

Build Tools
Ant (http://ant.apache.org) - Ant is a Java XML based build tool that has many built in libraries to automate builds and deploys. Most development environments have plugins to Ant, and Ant enjoys widespread support.

Maven (http://maven.apache.org) - Maven is another Java XML based build tool with many built in libraries. Maven differs in a few aspects from Ant. First Maven is object oriented. A developer will create a POM file to build code and that file will be inherited on all subprojects. If you are trying to decide whether to use Maven or Ant, I would recommend that if you have a basic J2EE app that does not deviate from good design patterns, then Maven is great. If you really need to create creative design patterns, I would recommend Ant.

Make (http://www.gnu.org/software/make) - You may be designing C++ apps and using Make. If so, I dropped the link, but chances are this is tattooed on your forearm by now.

Other Utilities worth Mentioning
KOSMOS - (http://labs.jboss.com/kosmos) - This product is so useful, if you are using JIRA, Subversion, CruiseControl, or SourceForge. If you are into high level understandings of where the code is at at any given moment, this tool provides a dashboard to several version control and defect tracking tools. This tool is a JBoss portlet, so you will need a JBoss application server to run this app. That's OK though. It's all free!

maven, defininitly not a relacement for ant

2008-04-19T13:56:00.000-07:00

Ant has many problems, but maven is definitely not the replacement for ant.

One key concept for the next generation build tool is that it should be much easier to use. Obviously, maven goes to the wrong direction.

The following is copied from http://fishbowl.pastiche.org/2007/12/20/maven_broken_by_design
for my reference to write presentation to prevent the moving from ant to maven.

Responsiveness

We have a joke around the office, when a new hire is setting up their development environment for the first time. “Now we go to lunch while Maven downloads the Internet.”

Software should be responsive. When you tell it to do something it should do it. Take a pristine Maven installation and tell it to build a Java application — i.e. perform its most obvious, primary function — and Maven will first say “Wait a moment, I have to download three dozen different components before I can even start doing what you asked me to do.”

“Ah”, you say. “That’s how maven works. It’s a modular system, you’re just using it to build a Java app.”

To which I reply: “Then don’t give me a spoon and tell me to use it to cut steak.”

The fact that all these components are downloaded separately and in serial mean the overhead of not including them is far greater than if they’d put them all (even plus a bunch more you might not need) in the core installation. Worse, though, this happens not when you’re installing maven, but when you’re trying to use it to do something else.

This process doesn’t stop at installation. Far too often you’ll run maven and it will gleefully traipse off through various repositories doing its own internal housecleaning before actually performing the build. It’s like walking up to a shop assistant and asking him to help you find a book, only to watch him dust shelves for fifteen minutes first.

Reliability

Consider two pieces of software. One uses maven (and 1–n artifact repositories) to manage its dependencies, the other keeps all its dependencies in source-control. How many potential points of failure are involved in checking out and building each product?

Repeatability

Builds must be repeatable. If you check out a particular version of your code and build it with particular versions of your tools, you should get a product that is binary-identical each time. (Modulo things like compiled-in build dates, obviously)

Maven seems to try as hard as it can to prevent this. Files go missing from public Maven repositories and suddenly a whole swathe of historical versions of open source projects can’t be built without hacking. ibiblio reorganises its directory layout and chaos ensues. Imagine what happens in ten years time when maven has been superceded by some new tool, public maven repository maintenance is an afterthought, and you desperately need to patch some legacy Java app?

For well-resourced projects, the solution is to maintain your own repository and ensure all your dependencies will be available from it, for all time, but even that won’t help you if you suddenly need the compile-time dependencies of a project you previously only used as a binary.

(A number of responses to this blog post have assumed that all my problems could be solved by a locally maintained repository, and/or a repository proxy. We have both. They help to some extent, but they in no way solve the problem completely. All they are is a band-aid over the fundamental issue, and once again, additional potential points of failure.)

Most open-source projects just assume their dependencies will continue to exist in “the cloud” for eternity.

Plugins are the worst culprit. Since the core of maven exists solely to download an Internet’s-worth of plugins to do the heavy lifting, and maven has a nasty habit of upgrading those plugins without any user-prompting whatsoever, builds can be crippled by some well-meaning committer “fixing” some piece of functionality. I’m told this has been fixed recently (or will be fixed soon) but versions should not be a moving target. v. 2.0.1 of your build tool should be v. 2.0.1 of your build tool. Forever.

Case Study: Dependency Management

One of the big strengths of Maven 2 is supposed to be the way it manages dependencies, including transitive dependencies. So if jar A requires jar B which requires jar C, Maven will sort all this out for you.

Tracking down dependencies and sorting out their transitive relationships is a tricky task, but it’s a tricky task you only ever have to do when you modify your dependencies. Maven, on the other hand, wants to do this job every time you build, which adds a huge responsiveness overhead, as the “pom” definition files of each dependency must be retrieved and analysed alongside their jars.

Dependencies may live in a number of different repositories, and these repositories are out of the control of the user, especially in the case of maven-built open-source projects that almost universally rely on the public ibiblio, apache and Codehaus repositories. This impacts both reliability, as all these repositories must be available, and repeatability, as changes to the repositories may have catastrophic effects on the build.

Reliability problems also creep in because maven, forced to do dependency resolution in each build, must hide a lot of what it’s doing from view lest it overwhelm the user even more. Conflicting transitive dependencies are resolved implicity, and you have to make a concerted effort (with clumsy tools) to manually find out what was going on.

Paradoxically, by trying to make dependency management easy, maven makes it incredibly hard. It becomes dangerously easy for a project to accumulate dependency cruft —— at best unnecessary, at worst conflicting —— and excruciatingly painful to remove them.

Conclusion

Maven 2 performs a difficult task, and there are a lot of moving parts — plugins, proxies, repositories — between typing mvn install on the command-line and getting a working system. But there has to be something fundamentally wrong with any tool that, whenever I use it, seems to have at least a 50% chance of completely fucking up my day

mvn + tomcat for hot deployment

2008-03-30T01:49:00.000-07:00

Also, one very powerful feature of Maven that I am messing around with right now is filtering and profile "mashups". Lets say, I want LRD (local rapid development ;-) on my workstation using Tomcat. Usually I would use the Jetty plugin because it is the ultimate for Maven LRD, but the majority of the time and to match what is in production, developers use Tomcat at a minimum. Here is a quick tip for creating a shared distributable app using the aforementioned.

In a existing Maven app, create the following structure:

src
|-main
|-filters
|-tomcat.properties
|-resources
|-context.xml

In your pom.xml we have something like
:

tomcat

false

src/main/filters/tomcat.properties

${basedir}/src/main/resources

true
../${build.finalName}/META-INF

context.xml

in tomcat.properties

context.docBase=${basedir}/target/${project.build.finalName}
context.path=/${project.build.finalName}

and in context.xml

Once you have all of this in place (along with a good cargo config found in this post) you will be on your way to a enjoyable, easy development setup.

So now, all you have to do to hot deploy your maven app to a running instance of Tomcat is type the following: mvn install -Ptomcat
This will compile and deploy your changes quickly. You can also set your IDE to copy jsp/xhtml files over using a keyboard shortcut mapping (easy to do with Idea) so for UI changes you don't have to hot deploy every time.
This example just scratches the surface of what mixing profiles with filtering can do. You could have a filtering/profile mechanism for every possible scenario.

open source e-commerce software

2008-03-27T09:58:00.000-07:00

--------------
osCommerce Online Merchant is an Open Source online shop e-commerce solution that is available for free under the GNU General Public License. (PHP)
--------------------------------
Apache: http://ofbiz.apache.org/feature-list.html

-----------------------------
http://www.magentocommerce.com/features
--------
php sites:

osCommerce , ZenCart, phpShop, myMarket

how to get sequence from mysql in cluster env

2008-03-22T21:43:00.000-07:00

If you have a cluster of application servers running and you would like to get a unique id across the cluster, the best way is to get the id from Database. Oracle has the sequence function, but MySQL does not have the function.

Here are several ways to work around the issue in MySQL.

Retrieving AUTO_INCREMENT column values using Statement.getGeneratedKeys()

   Statement stmt = null;
  ResultSet rs = null;

  try {

   //
   // Create a Statement instance that we can use for
   // 'normal' result sets assuming you have a
   // Connection 'conn' to a MySQL database already
   // available

   stmt = conn.createStatement(java.sql.ResultSet.TYPE_FORWARD_ONLY,
                               java.sql.ResultSet.CONCUR_UPDATABLE);

   //
   // Issue the DDL queries for the table for this example
   //

   stmt.executeUpdate("DROP TABLE IF EXISTS autoIncTutorial");
   stmt.executeUpdate(
           "CREATE TABLE autoIncTutorial ("
           + "priKey INT NOT NULL AUTO_INCREMENT, "
           + "dataField VARCHAR(64), PRIMARY KEY (priKey))");

   //
   // Insert one row that will generate an AUTO INCREMENT
   // key in the 'priKey' field
   //

   stmt.executeUpdate(
           "INSERT INTO autoIncTutorial (dataField) "
           + "values ('Can I Get the Auto Increment Field?')",
           Statement.RETURN_GENERATED_KEYS);

   //
   // Example of using Statement.getGeneratedKeys()
   // to retrieve the value of an auto-increment
   // value
   //

   int autoIncKeyFromApi = -1;

   rs = stmt.getGeneratedKeys();

   if (rs.next()) {
       autoIncKeyFromApi = rs.getInt(1);
   } else {

       // throw an exception from here
   }

   rs.close();

   rs = null;

   System.out.println("Key returned from getGeneratedKeys():"
       + autoIncKeyFromApi);
} finally {

   if (rs != null) {
       try {
           rs.close();
       } catch (SQLException ex) {
           // ignore
       }
   }

   if (stmt != null) {
       try {
           stmt.close();
       } catch (SQLException ex) {
           // ignore
       }
   }

Retrieving AUTO_INCREMENT column values using
             SELECT LAST_INSERT_ID()
  Statement stmt = null;
  ResultSet rs = null;

  try {

   //
   // Create a Statement instance that we can use for
   // 'normal' result sets.

   stmt = conn.createStatement();

   //
   // Issue the DDL queries for the table for this example
   //

   stmt.executeUpdate("DROP TABLE IF EXISTS autoIncTutorial");
   stmt.executeUpdate(
           "CREATE TABLE autoIncTutorial ("
           + "priKey INT NOT NULL AUTO_INCREMENT, "
           + "dataField VARCHAR(64), PRIMARY KEY (priKey))");

   //
   // Insert one row that will generate an AUTO INCREMENT
   // key in the 'priKey' field
   //

   stmt.executeUpdate(
           "INSERT INTO autoIncTutorial (dataField) "
           + "values ('Can I Get the Auto Increment Field?')");

   //
   // Use the MySQL LAST_INSERT_ID()
   // function to do the same thing as getGeneratedKeys()
   //

   int autoIncKeyFromFunc = -1;
   rs = stmt.executeQuery("SELECT LAST_INSERT_ID()");

   if (rs.next()) {
       autoIncKeyFromFunc = rs.getInt(1);
   } else {
       // throw an exception from here
   }

   rs.close();

   System.out.println("Key returned from " +
                      "'SELECT LAST_INSERT_ID()': " +
                      autoIncKeyFromFunc);

} finally {

   if (rs != null) {
       try {
           rs.close();
       } catch (SQLException ex) {
           // ignore
       }
   }

   if (stmt != null) {
       try {
           stmt.close();
       } catch (SQLException ex) {
           // ignore
       }
   }
}
 
}

What happes if you need multiple sequences in your app. The you may create sequence talbe several columns.

update sequence set id1=

opensource social network software

2008-03-20T23:53:00.001-07:00

" Pligg is an open source content management system available for download at no cost"

"Drupal.org is the official website of Drupal, an open source content management platform."

"NewsCloud is an open source media platform which you can use to launch your own grassroots media Web site. Or, you can get involved in the development of the NewsCloud platform"

"AROUNDMe is a GNU package. We use the General Public License (GPL) for our software meaning that you can copy our software, redistribute it, explore, change or modify the code."

"Dolphin Smart Community Builder is a universal, free, open source software that allows you to build any kind of online community."

"Even though PHPizabi is distributed unencrypted, it DOES NOT fall under any GPL license (Open Source does not necessarily mean OSD/GPL)."

"Elgg is an open source social networking platform developed for LAMP (Linux, Apache, MySQL, PHP) which encompasses weblogging, file storage, RSS aggregation, personal profiles, FOAF functionality and more."

"The software that powers Mugshot is 100% open source, including the client and the server."

" Web-based social bookmarking system. Allows multiple users to store, share and tag their favourite links online. License: GNU General Public License (GPL) "

"GetBoo just turned to open-source, under the GPL license at the end of April. I don't have any expectations, but I am confident it will add to my experience!"

-------------------

Dolphin

Dolphin, from Boonex, is a popular free community-building application that is being used for a number of dating sites. Many modifications have been developed, however many of them are only available for a fee. There is also a cost associated with removing the company’s links from your site.

PHPizabi

PHPizabi is another social networking script that charges a fee to remove their branding. They are rapidly approaching 100,000 downloads of their software, and have a few impressive-looking demo sites listed on their website.

Elgg

Elgg was developed with the educational industry in mind, but can be customized for any use. Many universities throughout the world have adapted the social software to fit their needs.

Mugshot

Developed by Red Hat, Mugshot allows you to post what you are reading and listening too, and share it with you friends. Mugshot is a little different, as both the client and server code are open source and available for download.

AroundMe

AroundMe is an open source social networking app that supports OpenID. They are based in Sweden. We haven’t seen many sites running on the platform.

---------------------
Top 40 Free Downloadable Open Source Social Networking Software
Vivalogo Resources

This is Vivalogo's list of best free, downloadable, open source social networking software (kinda hard to say all these words :) ).
Unlike some other lists you may find on the net, this one contains only really downloadable and functional software.
Note: listed in no particular order.
spree

spree is an expert search engine where users ask questions to find other participating users, who are knowledgeable in that area and willing to help.
iSocial

iSocial is a free social networking CMS software that allows you to create your own Friendster and Orkut like sites. Use bookmarks, dating and create groups with just one mouse click.
Mahara

Mahara is fully featured electronic portfolio, weblog, resume builder, and social networking system for connecting users and creating online communities.
Yogurt

This is a Social Network module for xoops CMS. You have seen Facebook, Orkut, Myspace , try Yogurt for Xoops!
VMukti

VMukti is a Unified Social Collaborative conferencing engine. Allows access through personalized, mashable web-interface. Core features:- Video conferencing, Audio conferencing, IP Telephony, Desktop sharing, Chat, Whiteboard, Presentation & More.
The PeopleAggregator

The PeopleAggregator is a next-generation social networking system that goes beyond the idea of social networks as mating games, and attempts to use open standards, network inter-connectivity and massive flexibility.
Appleseed

Appleseed is (augmented) social networking software, ie Friendster, only distributed. Sites running Appleseed will interoperate, and form the 'Appleseed Social Network.' Development is focused on privacy and security, as well as ease of configuration.
Mugshot Project

The Mugshot site lets you track what your friends are doing online across a variety of popular web sites ? music, photos, blog posts, and more.
GetBoo

Web 2.0 bookmarking system, both social (with tags) and private (with folders). Import and export your bookmarks from Firefox, IE, Mozilla, Netscape. Admin management section, translations, groups, bookmarklets, Firefox extension, RSS feeds, and more!
Akarru

Akarru is a social bookmarking engine, is used to build social bookmarkings sites, like www.blogmemes.com. Users posts links and promote links to front page using voting system.
Scuttle

Web-based social bookmarking system. Allows multiple users to store, share and tag their favourite links online.
SemanticScuttle

SemanticScuttle is a social bookmarking tool (based on Scuttle) experimenting new features as hierarchical tags, collaborative descriptions or OpenID authentification.
AROUNDMe

Create collaborative social websites (like Ning, Myspace, Yahoo or Google groups). Each group can create a multiple web pages. They get a drop in guestbook, blog, forum and wiki. Each group is fully customizable using xHTML, CSS, Javascript and PHP.
Clonesumating

Clonesumating is the open source version of the code that runs CONSUMATING.COM. It features many state of the art social networking functions including user profiles, user tagging, matching and discovery based on quirky tag combinations, group activities such as weekly photo contests and blog questions, an event calendar, RSS feeds for everything, etc. It is written primarily in mod_perl.
BeWelcome Rox

Get to know the global village and other cultures, share your place. BW Rox is the platform driving www.bewelcome.org and other social networks, aiming to bring people together in real life. Organize your travel or stay abroad, travelblog, meetings, ...
ICEcore

ICEcore open team collaboration software uses social networking to unify team workspaces w/ real-time web conferencing. Collaboration for knowledge networking, program management, communities-of-practice, telework, ...
Memephage

Memephage is an automated web log (blog). It passively gathers and summarizes links from various places. Currently: IRC, social MUDs, e-mail, and web browsers. Uses the POE multitasking and networking framework for Perl.
InteractOLE

A platform for the delivery and support of online learning. It differs from many other elearning platforms in that its aim is to concentrate on the social/interactive aspects of teaching and learning rather than the delivery of content to students.
Elgg

Elgg is an open source social networking platform developed for LAMP (Linux, Apache, MySQL, PHP) which encompasses weblogging, file storage, RSS aggregation, personal profiles, FOAF functionality and more.
CommunityNews

CommunityNews uses social bookmarking and bayesian techinques to provide periodic postings to blogs. Users can vote for or against RSS sources ti increase the chances that the source is used again. Spam filtering (bayesian) is provided by spam bayes.
OpenPNE

OpenPNE is a Social Networking Service Engine written in PHP. It has many features(friend control,friend invitation,diary,blog feeds,message box,etc).
MonkeyChow

Feed Aggregator Reader (branched from FeedOnFeeds) with Social Bookmarks (del.icio.us, Blogger, Newsvine, Technorati, mailto), Article Starring, Feed Tagging, OPML, Article Search, Reblogging and Refeeding, Aging, and Edit feed attributes.
NewsCloud

NewsCloud is an open source media platform for citizen journalism and the social news network hosted at NewsCloud.com.
Feed Me Links

Feed Me Links stores your bookmarks online so you can get to them anywhere. Import your favorites and share your links with friends. Add tags to organize your links. Discover new things.
WorldSpace

WorldSpace is a user-extensible shared virtual environment, aimed at being a next-generation social networking system.
Social Networking POC

A networking site on the lines of Orkut.Right now we plan to build it on Jboss seam and use a Java content management system like apache Jackrabbit as the backend. It would be more of a POC than an actual commercial app.
Zoints

Zoints is intimately aware that online communities are the most important aspect of the internet. Our free software solutions are designed to help solve the three major problems forum owners face: Member acquisition, Member retention and Profitability.
earth-life-simulation

A simulation of the world, there will be a global map representation and players can choose a country or civilization and develop it's social, political and military existence.
PHPizabi

PHPizabi is one of the most powerful social networking platforms on the planet. With literally thousands of websites powered by PHPizabi including everything from simple friends sites to the most complex networking super sites out there.
Ozcode

Ozcode is the source code behind Ozmozr.com, a microformat-aware RSS aggregator, social networking, resource sharing, identity aggregation and presentation site.
TallStreet

TallStreet.com is a new search engine concept where users make investments, with fictional money, in their favourite websites and the rankings are determined entirely by the users.
Jamss

Jamss is a social news site based off of Digg.com. Jamss allows for peer submission and review of web articles and can be adapted to fit a variety of themes. Jamss runs on PHP/MySQL.
Dolphin

Dolphin is open-source and free, although there is a cost associated with removing the company?s links from your site.
Ospo

Ospo is an opensource social portal project. It use standard function (add, remove friends, top10), forums integration, music module (artists directory with albums, songs), shoutcast integration, blog (add, delete, modify, view) and so on.
AstroSPACES

AstroSPACES is the world's first open source social networking solution. Coded from scratch, it is highly efficient and very easy to use.
FlightFeather

FlightFeather's goal is "social networking for everyone". This means that anyone should have a chance to run a popular social networking site -- on minimal hardware, and without wasting bandwidth.
SNOSS

Social Networking Open Source Software, an open source social networking framework, written in PHP, Javascript and MySQL with an AJAX UI.
OpenSocialNetwork

OpenSocialNetwork is a social network of open source. Its main task is to create a social network releasing the source code.
S3B

S3B - Social Semantic Search and Browsing - is a middleware that delivers a set of search and browsing components that can be used in J2EE web applications to deliver user-oriented features based on semantic descriptions and social networking.
Facelift

Facelift is a visualization and analysis software for online social networking services. It displays a given community as a node-link diagram and provides several search / filtering functions as well as cluster analysis features.

setup eclipse, tomcat and maven 2 for development

2008-03-16T15:32:00.000-07:00

copied from Nick Johnson: http://spatula.net/blog/2007/04/how-to-make-eclipse-tomcat-maven-2-and.html
-------------------
First, obviously, you need to install your prerequisites. Download and install Tomcat. Install the Sysdeo Tomcat plugin. You also want the Maven 2 Eclipse plugin. Installation of these is outside the scope of this post. It is also outside the scope of this post to explain Maven, Tomcat, Servlets and so-on. Use Google.

Next, bootstrap your project. I found it easiest to change into my Eclipse workspace directory, use mvn to create my archetype for my project, and then run mvn eclipse:eclipse inside the project directory it created. Then go to File | Import in Eclipse and import the project. Finally, enable the Maven 2 plugin for your imported project from the project's context menu, Maven 2 | Enable.

I found that the only way to make working with Maven bearable was to follow its default layout. This means that web.xml is going in src/main/webapp/WEB-INF and that all of the library dependencies are defined in pom.xml and all of the libraries will download into the Maven 2 Dependencies collection the first time you run mvn on the project.

Edit pom.xml and make sure you have your dependencies defined how you want them and that your project name and version are what you'd like.

Now is a good time to run a build of the project just to set up all of the remaining directories, like target. I did this by configuring an m2 build from the External Tools menu using my project's location as the Base directory with the goal "install".

Now set up the Tomcat plugin. From Window | Preferences | Tomcat, configure the appropriate Tomcat version and Tomcat home. From the context menu of your project, select Properties and then Tomcat. Check "is a Tomcat project." Set the context name to "/" and check "Can update context definition" and "Mark this context as reloadable." Set the subdirectory to "/target/your_project_name-your.project.version". The project name and version here must match what you've defined in pom.xml.

Now set up Eclipse to build directly to the Maven output directory. This allows you to avoid running a mvn build every time you make a change to a class or resource file. You will still need to run a mvn build if you add or change dependencies or if you change web.xml, however. From the project's properties context menu, choose Java Build Path and set the default output folder to target/your_project_name-your.project.version/WEB-INF/classes.

Lastly, from your project's context menu, choose Tomcat Project | Update Context Definition.

So to recap, here are the steps:

1. Download and install Maven 2, Eclipse, Tomcat, the Maven 2 plugin for Eclipse and the Tomcat plugin for Eclipse.
2. Create a project using Maven. Consult Maven's documentation for more detail or use an existing project that already has a pom.xml.
3. Run mvn eclipse:eclipse to generate Eclipse's metadata files from the project's pom.xml.
4. Import the project into your Eclipse workspace.
5. Edit pom.xml to define the version number and your dependencies.
6. Put web.xml in src/main/webapp/WEB-INF
7. Create a m2 external build and run it to create your target directory structure.
8. Configure the Tomcat plugin to look in Maven's target directory for your webapp's directory structure.
9. Configure Eclipse to build directly to Maven's target directory structure.

social network software

2008-03-16T14:07:00.000-07:00

"AboutMe is an online social networking software that enables you to
run your own Friendster, Orkut and Tribe.net site! This script allows
users to connect directly to people in their networks and community in
a fun and safe way. This site offers a large variety of features,
ranging from search tools to profile page. In addition, you will also
be able to add more features such as blog, with the advantage of
expanding features."

AboutMe
http://www.xceog.net/sn.php

----------------------------------------------------------------------

"AlstraSoft E-Friends is an online social networking software that
allows you to start your own site just like Friendster and Tribe.net.
The E-Friends software allows members to connect to people in their
personal networks and community, creating a new online interactive
resource that is based on a trusted network of friends and associates
on the internet."

E-Friends
http://www.alstrasoft.com/efriends.htm

----------------------------------------------------------------------

"DZOIC Handshakes is a software that allows you to build your own
social and business networking service with totally all features you
may need for this. Script is written in PHP programming language, it
uses MySQL database to store data and Smarty Template Engine to work
with templates and themes (see our system requirements at the top of
this page). All script source code is encoded with Zend Encoder.

Handshakes script is delivered to you with an installer, that will
guide you through all steps of installation. Handshakes script allows
members to connect to each other and build their personal network."

Handshakes
http://www.dzoic.com/features_overview.php

----------------------------------------------------------------------

"AROUNDMe is the perfect solution for community builders wishing to
bring together multiple mutual interest groups within a shared
knowledge network.

Features
-Membership Wiki, Blog, Events, Tasks, Polls.
-User multiple profiles.
-Group Wiki, Blog, Events, Tasks, Polls.
-Customisable social networking.
-Really simple publishing tools.
-Membership and group access control system.
-RSS
-Newsletters
-Configurable file upload
-Channels
-Tagging"

AROUNDMe
http://www.barnraiser.org/index.php?item_id=25

----------------------------------------------------------------------

DATING/MATCHMAKING software:

DatingBox
http://www.e-marvel.com/

Dating Agency Builder
http://www.datingbuilder.com/?og=1&wk=1412&da=8

PHPizabi
http://www.realitymedias.com/izabi/?L=showcase.about

osDate
http://www.tufat.com/script39.htm

eMeeting
http://datingscripts.co.uk/index.php

Match Agency
http://www.matchagency.biz/product.php

SkaDate
http://www.skadate.com/

----------------------------------------------------------------------

My Google search strategy:

Google Web Search: "social network OR networking software OR script OR package"
://www.google.com/search?hl=en&q=%22social+network+OR+networking+software+OR+script+OR+package%22

Google Web Search: "your own social network"
://www.google.com/search?hl=en&q=%22your+own+social+network

Debugging your Maven Project in Eclipse

2008-03-16T02:11:00.000-07:00

copied from http://docs.codehaus.org/display/MAVENUSER/Dealing+with+Eclipse-based+IDE
for personal reference

-----------------------------------

Debugging your Maven Project in Eclipse

Added by Franz Allan Valencia See , last edited by Brian Fox on Jul 16, 2007 (view change)

Note that there are two debug modes in maven: the Generic and the Surefire. If you want to debug maven itself, one of maven's plugins, or a maven project, use the Generic Approach. If you want to debug a test in your project launched by surefire, use the Surefire Approach.

Setting up Maven

Open %M2_HOME%/bin/mvn.bat

At line 30, you'll find this,

@REM set MAVEN_OPTS=-Xdebug -Xnoagent -Djava.compiler=NONE -Xrunjdwp:transport=dt_socket,server=y,suspend=y,address=8000

Uncommenting the line by deleting @REM

Also add

set MAVEN_OPTS=

in the :end section, otherwise the debug will be turned on even when you run the normal mvn.bat

Save that file as mvn-debug.bat (or any convenient name you may want). You now have two maven batch files, one for normal use, and one for debugging.

Now when you want to debug maven, run mvn-debug instead of mvn (i.e. instead of mvn install, use mvn-debug install)

Setting up Eclipse

Create a Java Project for the Maven Debug session

Create a new Java Project and call it "Maven Debug". This Project will never have any source code in it, it is just a shell for attaching the debugger.

Create Remote Java Application Debug Configurations

Create two debug configurations, one for Generic debugging called "Maven" and one for Surefire debugging called "Maven Surefire"

Run > Debug... and then right click on Remote Java Application and chose New Launch Configuration.

On the Connect tab click the Browse... button and select the "Maven Debug" project. Make sure that the Connection Properties > Port is 8000. (This matches the address value set on the MAVEN_OPTS command line in the mvn-debug.bat file from above)

On the Source tab click Add... and select all projects that have any Maven source that you want to debug.

Now do the same thing to create a second Remote Java Application called "Maven Surefire" with a port of 5005.

Generic Debugging

Select break points in the code you're are going to run.

Run maven in debug mode, e.g mvn-debug install

Attach the debugger to the running maven by selecting the "Maven" debug configuration created above.

Eclipse will now stop Maven at the breakpoints you have enabled.

Surefire Debugging

Select break points in the code you're are going to run.

From your command line, append the following to your maven command.

-Dmaven.surefire.debug

For example, to debug the tests run by the maven lifecycle install, do mvn install -Dmaven.surefire.debug

Wait for maven to pause its execution and display the message,

Listening for transport dt_socket at address: 5005

Attach the debugger to the running maven by selecting the "Maven Surefire" debug configuration created above.

Trouble Shooting Debugging

Source not found

I "stepped" into a code block and instead of the source I get "Source not found" with an "Edit Source Lookup Path..." button

This occurs because you do not have a project that contains the source for this class. You will need to checkout the source from the Maven subversion repository and then update the source path of the "Maven Debug" project to include this new project.

First you need to locate which project in the repository the class file belongs to.
Chances are this class exists on your classpath for a project. Select from the menu "Navigate > Open Type..." and enter the name of the class that is missing. In the matching types list select the correct class and click OK.

Ensure "Link with Editor" is enabled in your "Package Explorer". With the missing file selected the Package Explorer should have opened the class from a jar file from the classpath of a project. The name of the jar file should help in locating the project in the Maven subversion repository. The SCM location is also contained in the pom.xml file in the jar, this file is located at META-INF/groupdId/artifactId/pom.xml. E.g for the missing file "MavenArchiver.class" this file is contained in "maven-archiver-2.2.jar" and the pom.xml file in "META-INF.maven.org.apache.maven.maven-archiver" lists the SCM connection as "scm:svn:https://svn.apache.org/repos/asf/maven/shared/tags/maven-archiver-2.2".

Checking out the maven project you need and then run mvn eclipse:eclipse.

From the editor with the missing source, click on "Edit Source Lookup Path..." > "Add..." > "Java Project" > "OK" and select the newly checked out maven project.

The source does not match the debug stack trace

It is more than likely that you have a different version on your source path than the one in use by Maven.

The only way to fix this problem is to have matching versions of source to java class files.
This may require checking out the correctly tagged version of the plugin.

However there is no way to determine which version Maven is using as this is handled by the plexus classworld's class loader.

Debugging Maven Core with Eclipse

See Re: debugging maven with eclipse written by John J. Franey for some setup guidance. Those instructions should be merged into here at some stage.

FAQ

Question:

1. Why can't I just use Generic Debugging even for my tests?

Answer:

1. Because maven-surefire-plugin forks a new JVM by default, thus, the your MAVEN_OPTS are not passed. There are three fork modes of maven-surefire-plugin: Once (default), Never, and Always. For Once mode, surefire will run another JVM and will do all its testing there. For Never, it will use the same JVM instance as that of maven (this is normally not use so that you can isolate your tests). But if you really want to isloate your tests, run in Always mode. This will run a new JVM instance for every test sets it runs.

Question:

2. Will using argLine parameter of maven-surefire-plugin work instead of the -Dmaven.surefire.debug ?

Answer:

2. Yes. maven.surefire.debug acts like a shorthand version of argeLine=. So in most cases, using maven.surefire.debug be enough.

Development Environment

2008-03-16T02:08:00.000-07:00

Copied from Matt Raible: http://appfuse.org/display/APF/Development+Environment
For personal reference (before my wiki is setup)

-------------------
Development Environment

Added by Matt Raible, last edited by Matt Raible on Nov 24, 2007 11:02

About this Tutorial

This tutorial describes how to setup your development environment to compile/test/deploy AppFuse using Maven and your favorite IDE (Eclipse, IDEA or NetBeans). Eclipse works well for single-module projects, whereas IDEA and NetBeans work better with multi-module projects. Knowledge of Maven is not required to use AppFuse because the tutorials explain how to use it. If you're interested in learning Maven in-depth, please download the book Better Builds with Maven (it's free!).

Download - links to download Java, Maven and MySQL
Install - detailed instructions on where to install everything
Configure - how to configure your environment variables
Additional Tips - tools to boost your productivity

Download

Download Java 5 SE. AppFuse should work fine with Java 6, but Maven has issues with multi-module projects.
Download Maven 2.0.5+.
Download MySQL 5.0.27+.

Downloading these files to your desktop should work just fine.

Install

Make sure you have 7-Zip or WinZip installed (for Windows) and gnutar for OS X before installing these packages. Linux users should be fine with the default tar tools.

Create a "Tools" and "SDKs" folder on your hard drive. On Windows, I create these at c:\Tools and c:\SDKs. On *nix, I usually do /opt/dev/tools and install Java in the default locations. Make sure and install Sun's Java if you're on Linux. Now that it's GPL, it shouldn't be difficult to apt-get.
Create Environment variables for these folders - SDKS_HOME and TOOLS_HOME (optional)
Install Java SE (a.k.a. JDK) in the SDKs directory - keeping the directory names intact.
Unzip/Install Maven in the Tools directory - "maven-x" is what I use for the directory name, where x is the version number.
Install MySQL in the Tools directory.
Create a "Source" directory on your hard drive (this is where you'll put all your projects and their source code). On *nix, I usually create a "dev" folder in my home directory.

At this point, you should have a directory structure that looks something like the following:

SDKs
   - jdk1.5.0_10
Tools
   - maven-2.0.5
   - mysql
Source

After installing these tools, you'll need to setup an SMTP server as well. If there's an existing server you'd like to use, simply change the host name in src/main/resources/mail.properties.

Now you'll need to configure all these tools so that your operating system knows they're installed.

Configure

A Windows example is the only one shown here because it's assume the *nix folks are smart enough to figure it out for their system.

To set Environment Variables in Windows, either go to Control Panel -> System or right-click My Computer -> Properties.
Click on the _Advanced_ Tab and then click the _Environment Variables_ button.
Put focus on the second box (System Variables) by clicking on one of the existing values.
Enter the following variables:
- HOME = c:\Source
- SDKS_HOME = c:\SDKs
- TOOLS_HOME = c:\Tools
- JAVA_HOME = %SDKS_HOME%\jdk1.5.0_10
- MAVEN_HOME = %TOOLS_HOME%\maven-2.0.5
- MYSQL_HOME = %TOOLS_HOME%\mysql
- Append to the PATH variable: %JAVA_HOME%\bin;%MAVEN_HOME%\bin;%MYSQL_HOME%\bin

You should now be able to open a command prompt and type "java -version", "mvn -version" or "mysql" and not get errors.

Additional Tips

Use Cygwin on Windows for running Maven and doing all command line things. Install it in $TOOLS_HOME/cygwin.
Use Eclipse or IDEA. Install them in $TOOLS_HOME/eclipse-x or $TOOLS_HOME/idea-x. Multi-module Maven projects seem to work best in IDEA. NetBeans also has excellent Maven support, but it's not widely used among AppFuse developers and users. In Eclipse, Ctrl+Shift+R is your best friend; Ctrl+Shift+N in IDEA. See IDEs for more information on setting up an AppFuse-based project in your favorite IDE (Eclipse, IDEA, or NetBeans).

If you're starting work at a new client or at your company, you should do the following to help your development process become more efficient.

Setup a source control system. Subversion is highly recommended. Setting up a commit notification system is recommended when working with other developers. FishEye works great.
Setup a bug tracking system. Popular (free) choices are Bugzilla and Trac. The best one we've seen is JIRA. For more information see What issue tracking system is best for you?
Setup a Wiki. We love Confluence - but it's not free. Other recommended systems are JSPWiki and Trac. Trac has a wiki, source control browser and bug-tracking system all-in-one.
Setup a development box to host the source control system, the bug tracking system, and a wiki. Install Hudson, CruiseControl, Luntbuild or Continuum on this box to do continuous integration for your project. Setting up continuous integration with a Maven 2 project is a piece-of-cake, so you have no excuses! If you're interested in commercial CI systems, checkout Pulse or Bamboo. See Which open source CI tool is best suited for your application's environment? for more information on choosing a CI Server.
(optional) Install Roller and use it to report your daily status and issues. This will allow your client (or supervisor) to track your progress.

Buildix Rocks!
Buildix is a VMWare image (that can be installed on bare metal) that has Subversion, CruiseControl and Trac all pre-installed. Using it is highly recommended.

If installing and configuring all of this software doesn't boost your productivity, please read Tips for Productivity and Happiness at Work for more suggestions.

solve permgen out of member

2008-03-16T01:40:00.000-07:00

Copied from

Christian

http://my.opera.com/karmazilla/blog/2007/03/13/good-riddance-permgen-outofmemoryerror

from my personal reference.

Before thinking "yay! a fix for my problem!", read this: http://my.opera.com/karmazilla/blog/2007/03/15/permgen-strikes-back

The rest of this article has been left untouched.

I did it!

Yes, lads & lasses! If you've been annoyed with having JBoss or Tomcat die with an OutOfMemoryError every fifth time you redeploy your beloved brainchild of a web application, then this is your lucky day! Because I found a fix! It's true! Yay! ....!!!!!11one (can you tell this has been a pain to me?)

Boring but Serious Theory and Hypothesis part:
The "PermGen" error happens, when the Java virtual machine runs out of memory in the permanent generation. Recall that Java has a generational garbage collector, with four generations: eden, young, old and permanent.

In the eden generation, objects are very short lived and garbage collection is swift and often.

The young generation consists of objects that survived the eden generation (or was pushed down to young because the eden generation was full at the time of allocation), garbage collection in the young generation is less frequent but still happens at quite regular intervals (provided that your application actually does something and allocates objects every now and then).

The old generation, well, you figured it. It contains objects that survived the young generation, or have been pushed down, and garbage collection is even less infrequent but can still happen.

And finally, the permanent generation. This is for objects that the virtual machine has decided to endorse with eternal life - which is precicely the core of the problem. Objects in the permanent generation are never garbage collected; that is, under normal circumstances when the jvm is started with normal command line parameters.

So what happens when you redeploy your web application is, that your WAR file is unpacked and its class files loaded into the jvm. And here's the thing: almost always ends up in the permanent generation... Because, seriously, who wants to garbage collect their classes?!? Well, apparently application servers do, and here's how we make that happen;

PermGen, The Fix:
The standard garbage collector can't collect in the permanent generation, but the concurrent collector can. So the first thing we need to do is to make sure that the jvm uses the concurrent garbage collector. This is done by putting this:

-XX:+UseConcMarkSweepGC

In java's command line arguments. But this is not enough. We must also specifically tell it to collect in the permanent generation, and this is done with this command line argument:

-XX:+CMSPermGenSweepingEnabled

Good, now the concurrent collector will take the permantent generation under its wings. But wait! Classes are special, and the jvm is reluctant to let go of them, so we must also explicitly allow classes to be unloaded:

-XX:+CMSClassUnloadingEnabled

Now we're certain that the permanent generation will be properly cleaned. But this raises another issue: what if the jvm unloads classes that might still be needed? I imagine it can be hard for a collector to tell whether or not a class might still be needed with the amount of reflection that goes on in an application server. Therefor, we might want to tweak the amount of memory allocated for the permanent generation, and this is done with this command line parameter:

-XX:MaxPermSize=128m

Which will set the maximum size of our permanent generation to 128 megabytes - tweak it to fit your needs.

With these parameters properly applied to the jvm that runs your application server, your chances of running into a PermGen OutOfMemoryError will be considerably lessened.

Memcached as Hibernate second cache provider - implementation 2

2008-02-15T23:08:00.000-08:00

Here is the implementation based on another java memcached client library: http://bleu.west.spy.net/~dustin/projects/memcached/

I tested it on my development machine, it works. But I have not do any stress test to compare this implementation and the previous implement. If anybody is going to do it, please post the result here.

Here is the code for the two classes: provider and cache.

/**
* Memcached plugin for Hibernate
* configuration (hibernate.cfg.xml)
*
&lt pproperty name="cache.provider_class" &gt MemcachedHibernateCacheProvider &lt /pproperty &gt
&lt pproperty name="memcached.servers" &gt 192.168.1.2:11211,192.168.1.3:11211 &lt /pproperty &gt
&lt pproperty name="memcached.failover" &gt true &lt /pproperty &gt
&lt pproperty name="memcached.initConn" &gt 10 &lt /pproperty &gt
&lt pproperty name="memcached.minConn" &gt 10 &lt /pproperty &gt
&lt pproperty name="memcached.maxConn" &gt 1000 &lt /pproperty &gt
&lt pproperty name="memcached.maintSleep" &gt 30 &lt /pproperty &gt
&lt pproperty name="memcached.nagle" &gt false &lt /pproperty &gt
&lt pproperty name="memcached.socketTO" &gt 3000 &lt /pproperty &gt
&lt pproperty name="memcached.aliveCheck" &gt true &lt /pproperty &gt
&lt pproperty name="memcached.[cache_name_as_full_classname]" &gt 10s|20m|30h|40d &lt /pproperty &gt

*
*/

public class MemcachedHibernateCacheProvider2 implements CacheProvider {

private static final Log log = LogFactory.getLog(MemcachedHibernateCacheProvider2.class);

public final static String DEFAULT_CACHE_NAME="____DEFAULT_CACHE_REGION";
public static String serverlist;

private Hashtable cacheManager = new Hashtable();

/* (non-Javadoc)
* @see org.hibernate.cache.CacheProvider#start(java.util.Properties)
*/
public void start(Properties props) throws CacheException {

String servers = props.getProperty("memcached.servers");
//log.debug("*** --- *** server is "+ servers);
serverlist = servers.replace(',', ' ');
log.debug("*** --- *** server is "+ serverlist);
//System.out.println("*** --- *** server is "+ serverlist);

//if(StringUtils.isBlank(servers)){
if(servers==null || servers.trim().length()==0) {
throw new CacheException("configuration 'memcached.servers' get a empty value");
}

}

/* (non-Javadoc)
* @see org.hibernate.cache.CacheProvider#buildCache(java.lang.String, java.util.Properties)
*/
public Cache buildCache(String cacheName, Properties props) throws CacheException {
if((cacheName==null || cacheName.trim().length()==0))
cacheName = DEFAULT_CACHE_NAME;
MemcachedCache2 mCache = cacheManager.get(cacheName);
if(mCache == null){
String timeToLive = props.getProperty("memcached."+cacheName);
int secondToLive = -1;
//if(StringUtils.isNotBlank(timeToLive)){
if(timeToLive!=null && timeToLive.trim().length()>0){
timeToLive = timeToLive.toLowerCase().trim();
secondToLive = getSeconds(timeToLive);
}
System.out.println("=== Building cache named "+cacheName+" using secondToLive is "+secondToLive);
try{
mCache = new MemcachedCache2(serverlist, cacheName, secondToLive);
cacheManager.put(cacheName, mCache);
}catch(Exception e){
throw new CacheException(e);
//cacheManager.put(cacheName, cacheManager.get(DEFAULT_CACHE_NAME));
}
}
return mCache;
}

private static int getSeconds(String str){
try{
switch(str.charAt(str.length()-1)){
case 's':
return Integer.parseInt(str.substring(0, str.length()-1));
case 'm':
return Integer.parseInt(str.substring(0, str.length()-1)) * 60;
case 'h':
return Integer.parseInt(str.substring(0, str.length()-1)) * 3600;
case 'd':
return Integer.parseInt(str.substring(0, str.length()-1)) * 86400;
default:
return Integer.parseInt(str);
}
}catch(NumberFormatException e){
log.warn("Illegal configuration value : " + str, e);
}
return -1;
}

/* (non-Javadoc)
* @see org.hibernate.cache.CacheProvider#stop()
*/
public void stop() {
}

/* (non-Javadoc)
* @see org.hibernate.cache.CacheProvider#isMinimalPutsEnabledByDefault()
*/
public boolean isMinimalPutsEnabledByDefault() {
return false;
}

/* (non-Javadoc)
* @see org.hibernate.cache.CacheProvider#nextTimestamp()
*/
public long nextTimestamp() {
return Timestamper.next();
}
}

----------------------------------------------------------------------------------------

/**
* Cache plugin for Hibernate
* @author Hank Li
*/
public class MemcachedCache2 implements Cache {

private static final Log log = LogFactory.getLog(MemcachedCache2.class);

private static final int SIXTY_THOUSAND_MS = 60000;

private MemcachedClient mc;
private int secondToLive;
private String cacheName;

/**
* Creates a new Hibernate pluggable cache based on a cache name.
*
*/
public MemcachedCache2(String serverlist, String name, int secondToLive)
throws IOException {
mc = new MemcachedClient(AddrUtil.getAddresses(serverlist));
this.secondToLive = secondToLive;
this.cacheName = name + '_';
}

private String makeupKey(Object key) {
return cacheName + String.valueOf(key).hashCode();
}

/**
* Gets a value of an element which matches the given key.
*
* @param key
* the key of the element to return.
* @return The value placed into the cache with an earlier put, or null if
* not found or expired
* @throws CacheException
*/
public Object get(Object key) throws CacheException {
//log.debug("key: " + key);
System.out.println("*** key: " + key);
if (key == null) {
return null;
} else {
//Object rt = mc.get(makeupKey(key));

// Try to get a value, for up to 2 seconds, and cancel if it doesn't return
Object rt=null;
//synchronized way
try {
rt=mc.get(makeupKey(key));

}catch(Exception alle){
System.out.println("memcached exception"+alle);
throw new CacheException(alle);
}
/* asynchronized way
java.util.concurrent.Future f=mc.asyncGet(makeupKey(key));

try {
rt=f.get(2, TimeUnit.SECONDS);
//log.debug("future object="+f.toString());
//log.debug("rt is "+rt);
//rt=f.get();
} catch(TimeoutException e) {
// Since we don't need this, go ahead and cancel the operation. This
// is not strictly necessary, but it'll save some work on the server.
log.error("timeout excpetion", e);
f.cancel(false);
// Do other timeout related stuff
}catch(Exception alle){
log.error("memcached exception", alle);
}
*/
if (rt == null) {
log.debug("Element for " + key + " is null");
//System.out.println("--- Element for " + key + " is null");
}
return rt;

}

}

public Object read(Object key) throws CacheException {
return get((key));
}

/**
* Puts an object into the cache.
*
* @param key
* a key
* @param value
* a value
* @throws CacheException
* if the {@link CacheManager} is shutdown or another
* {@link Exception} occurs.
*/
public void update(Object key, Object value) throws CacheException {
put((key), value);
}

/**
* Puts an object into the cache.
*
* @param key
* a key
* @param value
* a value
* @throws CacheException
* if the {@link CacheManager} is shutdown or another
* {@link Exception} occurs.
*/
public void put(Object key, Object value) throws CacheException {

mc.set(makeupKey(key), secondToLive, value);

}

/**
* Removes the element which matches the key.

If no element matches,
* nothing is removed and no Exception is thrown.
*
* @param key
* the key of the element to remove
* @throws CacheException
*/
public void remove(Object key) throws CacheException {
mc.delete(makeupKey(key));
}

/**
* Remove all elements in the cache, but leave the cache in a useable state.
*
* @throws CacheException
*/
public void clear() throws CacheException {
mc.flush();
}

/**
* Remove the cache and make it unusable.
*
* @throws CacheException
*/
public void destroy() throws CacheException {

}

/**
* Calls to this method should perform there own synchronization. It is
* provided for distributed caches. Because EHCache is not distributed this
* method does nothing.
*/
public void lock(Object key) throws CacheException {
}

/**
* Calls to this method should perform there own synchronization. It is
* provided for distributed caches. Because EHCache is not distributed this
* method does nothing.
*/
public void unlock(Object key) throws CacheException {
}

/**
* Gets the next timestamp;
*/
public long nextTimestamp() {
return Timestamper.next();
}

/**
* Returns the lock timeout for this cache.
*/
public int getTimeout() {
// 60 second lock timeout
return Timestamper.ONE_MS * SIXTY_THOUSAND_MS;
}

public String getRegionName() {
return null;
}

/**
* Warning: This method can be very expensive to run. Allow approximately 1
* second per 1MB of entries. Running this method could create liveness
* problems because the object lock is held for a long period

*
* @return the approximate size of memory ehcache is using for the
* MemoryStore for this cache
*/
public long getSizeInMemory() {
log.warn("cann't getSizeInMemory in memcached!");
throw new CacheException("cann't getSizeInMemory in memcached!");
}

public long getElementCountInMemory() {
log.warn("cann't getElementCountInMemory in memcached!");
throw new CacheException("cann't getElementCountInMemory in memcached!");
}

public long getElementCountOnDisk() {
log.warn("cann't getElementCountOnDisk in memcached!");
throw new CacheException("cann't getElementCountOnDisk in memcached!");
}

public Map toMap() {
log.warn("cann't toMap in memcached!");
throw new CacheException("cann't toMap in memcached!");
}

public String toString() {
return "MemCached(" + getRegionName() + ')';
}
}

memcached hibernate cache provider

2008-02-15T22:19:00.000-08:00

Here is the code to use memcached as hibernate second cache provider. So far it is working wonderful for about a month. I am planning to add more objects to the cache to test its limitation.

This provider is based on http://www.whalin.com/memcached/. Most part are from Chinese developer Liu Dong's job.

I also implemented the provider based on http://bleu.west.spy.net/~dustin/projects/memcached/. But I have not test it. I will post it in the next release let everybody to test it so that we can compare both libraries.

There are two classes here. the first one is MemcachedHibernateCacheProvider.java, the second one is the MemcachedCache.java

/**
* Memcached plugin for Hibernate
* configuration (hibernate.cfg.xml)
*

 &lt pproperty name="cache.provider_class" &gt MemcachedHibernateCacheProvider &lt /pproperty &gt
&lt pproperty name="memcached.servers" &gt 192.168.1.2:11211,192.168.1.3:11211 &lt /pproperty &gt
&lt pproperty name="memcached.failover" &gt true &lt /pproperty &gt
&lt pproperty name="memcached.initConn" &gt 10 &lt /pproperty &gt
&lt pproperty name="memcached.minConn" &gt 10 &lt /pproperty &gt
&lt pproperty name="memcached.maxConn" &gt 1000 &lt /pproperty &gt
&lt pproperty name="memcached.maintSleep" &gt 30 &lt /pproperty &gt
&lt pproperty name="memcached.nagle" &gt false &lt /pproperty &gt
&lt pproperty name="memcached.socketTO" &gt 3000 &lt /pproperty &gt
&lt pproperty name="memcached.aliveCheck" &gt true &lt /pproperty &gt      
&lt pproperty name="memcached.[cache_name_as_full_classname]" &gt 10s|20m|30h|40d &lt /pproperty &gt

*/

public class MemcachedHibernateCacheProvider implements CacheProvider {

private static final Log log = LogFactory.getLog(MemcachedHibernateCacheProvider.class);

public final static String DEFAULT_CACHE_NAME="____DEFAULT_CACHE_REGION";

private Hashtable cacheManager = new Hashtable();

/* (non-Javadoc)
* @see org.hibernate.cache.CacheProvider#start(java.util.Properties)
*/
public void start(Properties props) throws CacheException {
SockIOPool pool = SockIOPool.getInstance();
String servers = props.getProperty("memcached.servers");
System.out.println("*** --- *** server is "+ servers);
log.info("*** --- *** server is "+ servers);
String[] serverlist = servers.split(",");
//if(StringUtils.isBlank(servers)){
if(servers==null || servers.trim().length()==0) {
throw new CacheException("configuration 'memcached.servers' get a empty value");
}
pool.setServers(serverlist);
pool.setFailover( Boolean.valueOf(props.getProperty("memcached.failover")) );
pool.setInitConn( Integer.valueOf(props.getProperty("memcached.initConn")) );
pool.setMinConn( Integer.valueOf(props.getProperty("memcached.minConn")) );
pool.setMaxConn( Integer.valueOf(props.getProperty("memcached.maxConn")) );
pool.setMaintSleep( Integer.valueOf(props.getProperty("memcached.maintSleep")) );
pool.setNagle( Boolean.valueOf(props.getProperty("memcached.nagle")) );
pool.setSocketTO( Integer.valueOf(props.getProperty("memcached.socketTO")) );
pool.setAliveCheck( Boolean.valueOf(props.getProperty("memcached.aliveCheck")) );
pool.initialize();
}

/* (non-Javadoc)
* @see org.hibernate.cache.CacheProvider#buildCache(java.lang.String, java.util.Properties)
*/
public Cache buildCache(String cacheName, Properties props) throws CacheException {

if((cacheName==null || cacheName.trim().length()==0))
cacheName = DEFAULT_CACHE_NAME;
MemcachedCache mCache = cacheManager.get(cacheName);
if(mCache == null){
String timeToLive = props.getProperty("memcached."+cacheName);
int secondToLive = 3600 * 24 * 2; //default is 2 days
//if(StringUtils.isNotBlank(timeToLive)){
if(timeToLive!=null && timeToLive.trim().length()>0){
timeToLive = timeToLive.toLowerCase().trim();
secondToLive = getSeconds(timeToLive);
}
//System.out.println("=== Created cache "+cacheName+" with secondToLive="+secondToLive);
log.info("Created cache "+cacheName+" with secondToLive="+secondToLive);
mCache = new MemcachedCache(cacheName, secondToLive);
cacheManager.put(cacheName, mCache);
}
return mCache;
}

private static int getSeconds(String str){
try{
switch(str.charAt(str.length()-1)){
case 's':
return Integer.parseInt(str.substring(0, str.length()-1));
case 'm':
return Integer.parseInt(str.substring(0, str.length()-1)) * 60;
case 'h':
return Integer.parseInt(str.substring(0, str.length()-1)) * 3600;
case 'd':
return Integer.parseInt(str.substring(0, str.length()-1)) * 86400;
default:
return Integer.parseInt(str);
}
}catch(NumberFormatException e){
log.warn("Illegal configuration value : " + str, e);
}
return -1;
}

/* (non-Javadoc)
* @see org.hibernate.cache.CacheProvider#stop()
*/
public void stop() {
}

/* (non-Javadoc)
* @see org.hibernate.cache.CacheProvider#isMinimalPutsEnabledByDefault()
*/
public boolean isMinimalPutsEnabledByDefault() {
return false;
}

/* (non-Javadoc)
* @see org.hibernate.cache.CacheProvider#nextTimestamp()
*/
public long nextTimestamp() {
return Timestamper.next();
}
}

-----------------------------------------------------------------------------

public class MemcachedCache implements Cache {

private static final Log log = LogFactory.getLog(MemcachedCache.class);

private static final int SIXTY_THOUSAND_MS = 60000;

private MemCachedClient mc;
private int secondToLive;
private String cacheName;

/**
* Creates a new Hibernate pluggable cache based on a cache name.
*
*/
public MemcachedCache(String name, int secondToLive) {
mc = new MemCachedClient();
mc.setCompressEnable(true);
mc.setCompressThreshold(4096);
this.secondToLive = secondToLive;
this.cacheName = name + '_';
}

private String makeupKey(Object key){
return cacheName + key.toString().hashCode();
}

/**
* Gets a value of an element which matches the given key.
*
* @param key
* the key of the element to return.
* @return The value placed into the cache with an earlier put, or null if
* not found or expired
* @throws CacheException
*/
public Object get(Object key) throws CacheException {
//if (log.isDebugEnabled()) {
//log.debug("key: " + key);
//}
//System.out.println("*********get key: in cache " + cache_name + " is " + key);
if (key == null) {
return null;
} else {
Object rt = mc.get(makeupKey(key));
if (rt == null) {
//if (log.isDebugEnabled()) {
//log.debug("Element for " + key + " is null");
//System.out.println("-- Element for " + key + " is null");
//}
return null;
} else {
return rt;
}
}

}

public Object read(Object key) throws CacheException {
return get((key));
}

/**
* Puts an object into the cache.
*
* @param key
* a key
* @param value
* a value
* @throws CacheException
* if the {@link CacheManager} is shutdown or another
* {@link Exception} occurs.
*/
public void update(Object key, Object value) throws CacheException {
put((key), value);
}

/**
* Puts an object into the cache.
*
* @param key
* a key
* @param value
* a value
* @throws CacheException
* if the {@link CacheManager} is shutdown or another
* {@link Exception} occurs.
*/
public void put(Object key, Object value) throws CacheException {
if(secondToLive <=0 ) mc.set(makeupKey(key), value); else{ Calendar cal = Calendar.getInstance(); cal.add(Calendar.SECOND, secondToLive); mc.set(makeupKey(key), value, cal.getTime()); } } /** * Removes the element which matches the key.

If no element matches,
* nothing is removed and no Exception is thrown.
*
* @param key
* the key of the element to remove
* @throws CacheException
*/
public void remove(Object key) throws CacheException {
mc.delete(makeupKey(key), null);
}

/**
* Remove all elements in the cache, but leave the cache in a useable state.
*
* @throws CacheException
*/
public void clear() throws CacheException {
mc.flushAll();
}

/**
* Remove the cache and make it unuseable.
*
* @throws CacheException
*/
public void destroy() throws CacheException {

}

/**
* Calls to this method should perform there own synchronization. It is
* provided for distributed caches. Because EHCache is not distributed this
* method does nothing.
*/
public void lock(Object key) throws CacheException {
}

/**
* Calls to this method should perform there own synchronization. It is
* provided for distributed caches. Because EHCache is not distributed this
* method does nothing.
*/
public void unlock(Object key) throws CacheException {
}

/**
* Gets the next timestamp;
*/
public long nextTimestamp() {
return Timestamper.next();
}

/**
* Returns the lock timeout for this cache.
*/
public int getTimeout() {
// 60 second lock timeout
return Timestamper.ONE_MS * SIXTY_THOUSAND_MS;
}

public String getRegionName() {
return null;
}

/**
* Warning: This method can be very expensive to run. Allow approximately 1
* second per 1MB of entries. Running this method could create liveness
* problems because the object lock is held for a long period

memcached, the best choice for distributed hibernate second cache

2008-01-22T15:53:00.000-08:00

After painful evaluation of the terracotta, finally I decided to drop it.

The terracotta concept is good and attracting. But when I am testing, it causes us a lot of trouble for class loading.

After many workarounds, terracotta server is up and running. But the cpu is pretty high under load and GC time killed the application since responding time is the key for the web application.

Finally, I decide to write the memcached provider for the hibernate, use use memcached as the second level cache for hibernate. The client API I used is http://www.whalin.com/memcached/. I have not optimized the code yet, but the cpu and memory usage is much lower than terracotta server.

I also eveluate other java cache solutions, all of them have their advantages. But still none of them can bypass the limitation of heap size and will cause big GC time.

Compared to those java cache solution, memcached's get/set operation is slower, but comparing to the database operation, the difference of the get/set operations between memcached and ehcache can be ignored.

If there are more and more data to cache on the road, hibernate + memcached as second level cache is the way to go.

I am also doing research on the way to use ehcache as local and short term cache and use the memcached as the long term and distributed cache.

I will post more information about my memcached cache provider for hibernate.

which cache for the hibernate? memcached, EHCache or terracotta?

2007-10-10T17:29:00.000-07:00

I am in the process to evaluate which cache is better for my purpose. I will post my research result here.

Greg Luck has done a rough test for memcached and EHCache.

http://gregluck.com/blog/archives/2007/05/comparing_memca.html

The data shows EHCache is much faster than memcached. I think the testing is not fair, since the memcached is for distributed cache and test for EHCache has tested the local cache only.

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