Apache ActiveMQ® is the most popular open source, multi-protocol, Java-based message broker. It is widely used in a lot of multi service application environments where we need to pass messages between services. All this type of environments (kubernets, docker swarm etc. ) are used to be able to monitor and control the component services using… Read More »
In an Oracle database I was trying to convert an existing view to a table and preserve the data in it. For most of my views the following SQL worked perfectly: Then in one on the instances the following error occurred: While inspecting the SQL code of the views I noticed that the view with… Read More »
Several months ago I moved my childhood turntable setup to my new place. I will just post here some images of the set-up I like so much. Basically it was the standard turntable you could buy in the late 1980s in communist Romania. I remember that my dad bought it sometimes in 1983 or 1984.… Read More »
In a high load system deployed on Jboss Application Server the following optimizations for data source pool resources may be needed. 1. Change the minimum and maximum pool size of a data source (MyDS). This will ensure that we always have a minimum number of allocated connections and also we set a threshold to the… Read More »
Second level cache is an extremely powerful way to improve performance of an enterprise application if done right. In the following I will explain how to activate and configure second level cache when using Hibernate and Jboss 7.4+ application server. Jboss 7.4 comes with Infinispan as the build in second level cache solution. This makes… Read More »
In the following post I will describe my quick procedure I always use to debug the database queries generated by an application that hit an Oracle database. In a lot of cases your queries that hit the database are not written explicitly by a developer. That may be the case when intermediate layers as Hibernate… Read More »
Often times I find trying to start Edge on an old data-center jump station and I just click and nothing happens. This is the direct result of an Edge process that went zombie. A quick way to kill an Edge session that is acting as a zombie and will not allow you to start a… Read More »
In general is good to have a separate tablespace for your index tables. Sometimes the default tablespace, in our case DATA, is used by an application using hibernate layer to automatically create all the tables and indexes. Then the issue is how to move the automatically created indexes to the special created tablespace for indexes,… Read More »
A common mistake is to set the alternatives just for java sdk. This can lead to issues when several java versions are present. Jasper Reports a well knows Java library used to generate ad-hoc pdf reports compiles the report templates and the temporary classes using the default system javac not the javac of the java… Read More »