Clustering scheduled jobs with Quartz and Terracotta
We’re using Quartz to handle scheduled jobs in our java applications. Since we cluster our apps for failover using Terracotta, we need to address the issue of how to failover… Read more »
Category: Other
Weird racing clock problem on VMWare Linux Guests
A while back we installed a new Dell server with a low-power Xeon 3GHz L3110 CPU to run some other essential network infrastructure. We chose the specific server configuration because… Read more »
Hazelcast distributed locks for easy fault tolerance
Hazelcast (hazelcast.com) provides an easy way to implement distributed locking to allow your applications to run multiple, fault-tolerant instances without worrying about issues related concurrent access to shared resources (like… Read more »
Wicket dropdowns with mismatched models
Sometimes you have a class containing an id of another (lets say a Machine class containing an owner id rather than an Owner object). The owner id is actually a… Read more »
Enforcing multiple levels of page access in Wicket
In Wicket when you want to require user login for some pages, you typically inherit the pages from a superclass called say ProtectedPage and then use a wicket SimplePageAuthorizationStrategy to… Read more »
Embedded Jetty instead of Tomcat
I recently used embedded Jetty for a small REST server project and it was a revelation. It took exactly no time to get it running and now I can deploy… Read more »
JDBC vs IBATIS vs Hibernate
Christoph has spent the last couple of weeks refactoring a web project to use IBATIS instead of Hibernate. I also refactored a smaller project to use IBATIS instead of JDBC…. Read more »
LDAPAuthentication with Active Directory
Here’s something I had to piece together myself from various code fragments. Its a class to authenticate a user in Windows Active Directory environment using LDAP. It first locates the… Read more »
Adding an activity monitor to your wicket application
Sometimes its useful in an application to have a list of users who are currently logged onto an application on a server. To do this, you first need a SessionAttributeListener… Read more »
How to display images in Wicket
For someone starting out with Wicket, it can be tricky to figure out basic things like how to display images. Here are basic three scenarios: 1. Simple fixed image –… Read more »