Scala vs. Groovy

Surprising thoughts on Scala from Groovy creator James Strachan : Scala as the long term replacement for java/javac?

I can honestly say if someone had shown me the Programming Scala book by by Martin Odersky, Lex Spoon & Bill Venners back in 2003 I'd probably have never created Groovy.

The downfall of Agile

The agile lead goes crazy when he learns his agile team has not been following the principles of the agile manifesto. At least the team implemented the continuous integration.

Resolving HTTP Error 413 - Request entity too large

This error has been reported by a few users to me regarding application which seats on Tomcat fronted by Apache and configured to use Apache Tomcat Connector mod_jk

Request Entity Too Large
The requested resource /testapp/ does not allow request data
with GET requests, or the amount of data provided
in the request exceeds the capacity limit.

The mod_jk.log file shows

[error] ajp_marshal_into_msgb::jk_ajp_common.c (415): failed appending the header value
[info] ajp_service::jk_ajp_common.c (1927): Creating AJP message failed, without recovery
[info] jk_handler::mod_jk.c (2270): Aborting connection for worker=worker1

The only solution I found is to increase the maximum AJP packet size. I added the line worker. worker1.max_packet_size=65536 to the worker.properties file and the line packetSize="65536" to the AJP Connector element in Tomcat’s server.xml

# workers.properties
worker.worker1.type=ajp13
worker.worker1.host=127.0.0.1
worker.worker1.port=8009
worker.worker1.max_packet_size=65536

#server.xml

Could not find a valid processor version implementation

I got an error like the following

Could not find a valid processor version implementation
from weblogic.xml.jaxp.RegistrySAXTransformerFactory

while trying to generate JUnit test results for Weblogic application with Ant JUnit task and merge all the XML test reports into one HTML document by using Ant JUnitReport task.

The "WebLogic Server Known and Resolved Issues" list mentions the workaround for CR301115 "Could not find a valid processor version implementation from weblogic.xml.jaxp.RegistrySAXTransformerFactory" as defining the XML parser class. Unfortunately the suggested workaround does not seem to work for me. After browsing around, I found that the JUnitReport task needs Apache Xalan processor for processing XML documents and I need to change classpath order by renaming xalan.jar used by ANT to something like axalan.jar

Continuous integration survey

The author of Continuous Integration survey - What companies expect and solutions provide tries to answer on these questions :

How do the companies run their integration processes and what is important to them?
What do companies expect from Continuous Integration solutions
and how can available Continuous Integration solutions fulfill their needs?

java.lang.NoClassDefFoundError: sun/awt/X11GraphicsEnvironment

This error was reported by QA during an attempt to display charts in Weblogic application created with JFreeChart

Root cause of ServletException.
java.lang.NoClassDefFoundError: sun/awt/X11GraphicsEnvironment
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:164)
at java.awt.GraphicsEnvironment.getLocalGraphicsEnvironment(GraphicsEnvironment.java:68)
at java.awt.image.BufferedImage.createGraphics(BufferedImage.java:1141)
at org.jfree.chart.JFreeChart.createBufferedImage(JFreeChart.java:1212)
at org.jfree.chart.JFreeChart.createBufferedImage(JFreeChart.java:1193)
at org.jfree.chart.ChartUtilities.writeChartAsPNG(ChartUtilities.java:174)
at org.jfree.chart.ChartUtilities.writeChartAsPNG(ChartUtilities.java:120)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:743)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:856)
at weblogic.servlet.internal.StubSecurityHelper$ServletServiceAction.run(StubSecurityHelper.java:227)
at weblogic.servlet.internal.StubSecurityHelper.invokeServlet(StubSecurityHelper.java:125)
at weblogic.servlet.internal.ServletStubImpl.execute(ServletStubImpl.java:283)
at weblogic.servlet.internal.ServletStubImpl.execute(ServletStubImpl.java:175)
at weblogic.servlet.internal.WebAppServletContext$ServletInvocationAction.run(WebAppServletContext.java:3228)
at weblogic.security.acl.internal.AuthenticatedSubject.doAs(AuthenticatedSubject.java:321)
at weblogic.security.service.SecurityManager.runAs(SecurityManager.java:121)
at weblogic.servlet.internal.WebAppServletContext.securedExecute(WebAppServletContext.java:2002)
at weblogic.servlet.internal.WebAppServletContext.execute(WebAppServletContext.java:1908)
at weblogic.servlet.internal.ServletRequestImpl.run(ServletRequestImpl.java:1362)
at weblogic.work.ExecuteThread.execute(ExecuteThread.java:209)
at weblogic.work.ExecuteThread.run(ExecuteThread.java:181) 

It appears that I have to set java.awt.headless to true so that the JRockit JVM will implement AWT in software, rather than attempting to use non-existent hardware-based monitor on Linux box. The follow property was specified at the java command line JFreeChart are correctly displayed now.

-Djava.awt.headless=true

Oracle JRockit Mission Control

We want to monitor Weblogic 9.2 running Jrockit R27.3.1-1 on Red Hat Linux from Windows XP machine. Guided by Oracle JRockit Mission Control 3.0.3 tutorial I added

-Xmanagement:ssl=false,authenticate=false,autodiscovery=true,port=7091 

flag to Weblogic 9.2 start up script and restarted server. Also, I asked Unix admin to open port 7091 on Linux box, but when I try to connect with Oracle JRockit Mission Control I got an error

Could not open Management Console for servername.
java.rmi.ConnectException: Connection refused to host: N.N.N.N; nested exception is: 
java.net.ConnectException: Connection timed out: connect

Trying another approach I installed Oracle JRockit Mission Control 3.0.3 on Red Hat Linux and attempted to launch Oracle JRockit Mission Control 3.0.3 on Red Hat Linux with enabled X11 forwarding in SecureCRT and using XMing as X Window Server. So far I got only JRockit Mission Control splash screen and the following error message appeared:

foobar:/data/bea/monitoring/jrmc-3.0.3-1.5.0/bin> ./jrmc
Oct 28, 2008 9:23:45 AM com.jrockit.console.model.ConsoleModel initializeSettings
INFO: Reading console settings from /home/foobar/
.missioncontrol/consolesettings.default.xml
No fonts found; this probably means that the fontconfig
library is not correctly configured. You may need to
edit the fonts.conf configuration file. More information
about fontconfig can be found in the fontconfig(3) manual
page and on http://fontconfig.org

This issie was resolved by Unix administrator who installed fonts-xorg-base base fonts package that is required by the X Window System

Next two errors appears during launch of Mission Control Memleak and Mission Control JRA:

A license for Memory Leak Detector could not be found on the JRockit 
at (1.5) weblogic.Server (16089).
Error: Can not find component Memory Leak Detector for JRockit * in the license file.
Please check http://www.jrockit.com/license for license updates.

Could not open JRA for Create JRA-recording on (1.5) weblogic.Server (16089).
javax.management.RuntimeMBeanException: RuntimeException thrown in operation start
[...]
Caused by: java.lang.RuntimeException: java.lang.IllegalAccessException: 
Your license does not allow JRA to be started: 
Error: Can not find component JRA for JRockit * in the license file.

The following post How to get and install a JRockit license for JRockit versions < R27.6 was helpful for resolving JRockit license issues.

1. Download the legacy license package from http://download2.bea.com/pub/license/All%20Products/BEA_WebLogic.zip and unzip it somewhere.
2. Copy the file LIC-WLRT20.txt to the jre directory under the home directory of the legacy JRockit (%JROCKIT_HOME%/jre/).
Note: if this for some reason is not possible, follow the instructions here: http://edocs.bea.com/jrockit/geninfo/diagnos/conf_run.html#wp1077371
3. Rename the license file to license.bea.

Looks like the restart of JRockit is required to apply a new license. Finally I'm happy owner of Oracle JRockit Mission Control 3.0.3.