jueves, mayo 24, 2012

I'm guided by this birthmark on my skin, I'm guided by the beauty of our weapons, First we take Manhattan, then we take Berlin (First We Take Manhattan - Leonard Cohen)

On May 23, I was at Berlin as speaker in LinuxTag. I talked about how to test modern Enterprise Java Applications using open source tools.

Presentation abstract was:

Ten years ago to present, Enterprise Java Applications have suffered many changes. We have moved from Enterprise Applications built with JSP+Servlet and EJB, to much more complex applications. Nowadays with the advent of HTML5 or JavaScript libraries like JQuery, client side development has changed significantly. With the emergence of web frameworks like Spring MVC or JSF,  server side code has quite changed compared to the one used when each web-form was mapped to a Servlet. And also persistence layer has changed with Java Persistence standard or with new database approaches like Data-Grid, Key-Values stores or Document stores.
Moreover, architectural changes have occurred too, REST-web applications have grown in popularity or AJAX is used to create asynchronous web applications. Due to development of Enterprise Java Applications have changed during these years, so testing frameworks have changed accordantly. The main topic of this speech will be how to test Enterprise Java Applications using these new frameworks.
In the first part of this presentation we are going to explore how to test JavaScript written on client side, how to write unit tests of server side code, and how to validate persistence layer. Next part of presentation will be focused on how to write integration tests on server side and acceptance tests on full Enterprise Java Applications (joining client and server side) and an introduction about testing REST-web applications. Finally we will show how to integrate all kind of test on your continuous integration system and run acceptance tests on test environment.

Session will combine theory with interactive practice using only open-source projects.

I have uploaded slides to slideshare so you can  take a look (sorry for red and blue colours):

How to Test Enterprise Java Applications
View more presentations from Alex Soto

Also if you want you can download the code that it was used in demo sections.

Javascript Unit Testing with JS Test Driver
NoSQL Unit Testing with NoSQLUnit
Integration Tests with Arquillian
Acceptance Tests with Thucydides

Please let me warn you that NoSQLUnit is an open source project that I am developing, and it is on early stages, in next month, project will have a better look by supporting more NoSQL systems like Neo4j, Cassandra or CouchDb and having an official (not snapshot) release. If you want you can follow me on Twitter or subscribing to NoSQLUnit github repository and receive the last news of this JUnit extension.

For any question do not hesitate to write them in comments section or sending me an email.

I would like to say thank you to linuxtag folks for treating me so well and all people who came to presentation, for all of them a big thank you.

Music: http://www.youtube.com/watch?v=JTTC_fD598A&ob=av2e

jueves, mayo 03, 2012

Nasha nasha krovatka delala shik - shik, Ya tvo pianino , a ty moi nastroishchik, My tak letali chto ne zametili tvoyu matʹ, Ahaa..I ona skazala chto ya prosto blaz (Mama Lyuba - Serebro))

When we develop any application, after we finish it or when we end up any of its module, we start optimization process. Most applications contain database access, and if you are using an ORM, probably you will use hibernate. Optimizing hibernate persistence layer, requires to be prepared to read, understand and evaluate sql.

If we take an overview on hibernate configuration, two properties, hibernate.format_sql and hibernate.use_sql_comments, should be enabled to print performed sql code through console.

This is a good start but it seems that we need more information to make an accurate diagnosis of performance like connection events, returned data on queries, or parameters binding (hibernate shows parameters values with question mark ?) . Hence, we need another way to inspect generated sql. Log4jdbc is a jdbc driver that can log sql/jdbc calls. In fact log4jdbc is an implementation of proxy pattern which will automatically load popular jdbc drivers (Oracle, Derby, MySql, PostgreSql, H2, Hsqldb, ...), intercept calls, log information, and then send data to "spied" driver.

In log4jdbc, there are 5 loggers that can be used depending on data to monitor:
  • jdbc.sqlonly: logs executed sql with binding arguments replaced with bound data.
  • jdbc.sqltiming: logs how long a sql took to execute.
  • jdbc.audit: logs all jdbc calls except for ResultSets.
  • jdbc.resultset: same as jdbc.audit plus ResultsSets.
  • jdbc.connection: logs open and close connection events.
In this post we are going to see how to configure log4jdbc-remix, a fork of log4jdbc, which apart from inheriting log4jdbc capabilities, also let us:
  • jdbc.resultsettable: log results set in table format.
  • configure it as datasource.
  • available in maven repository (log4jdbc is not present on maven repositories).
For this example we are going to use the project created by JPA Spring Template which contains two entities Order and Item associated with one-to-many relationship, and one test that executes some database operations.

First thing to do is add log4jdb-remix and slf4j-log4j12 dependencies to project:

Next thing to do is configure active loggers.  Depending on the data we are interested to monitor, we activate the required loggers. As an example let's configure log4j.xml so result set is printed in table format and also time taken to execute each query is shown.

After configuring loggers, run test and inspect the output.

Output is printed in a fashion format, queries contains bind parameters (not a question mark (?)), and process time is also informed.

Notice that logging more or less information is simply a matter of configuring a log. Moreover depending on log level, more or less information will be provided in each case. If logger is configured in DEBUG class name and line number (if available) at which the sql was executed will be included. In INFO will include only sql, and finally ERROR which show stacktraces if any SQLException occurs.

Optimizing hibernate applications can imply touching many parts of an application (JVM configuration, database engine, network, …) but one very important aspect to take care is the number of queries that are sent to RDBMS (for example N+1 problem), and the amount of data that is retrieved from database (Projection problem), and log4jdbc-remix perfectly fits to help in this purpose.

As final note, log4jdbc(-remix) is a jdbc logger, so it is not necessary to use only in hibernate applications, can be used with any framework that uses a datasource.

I wish this library would help you.

Keep Learning,

Download Code
Music: http://www.youtube.com/watch?v=h9HRHOXfRBI