Category Archives: Programming

Learning GO: Concurrently execute expensive validations on several items and return the list of validation errors with #golang

By | May 24, 2018

Most of the time software for real use cases from financial industry is just validating inputs. When I say validating inputs I refer to business validation that actually checks against standard formats or generates complex validation against business rule sets. Usually this step is very important because it is the step that gets hammered with… Read More »

#Docker #Jboss dies with java.lang.OutOfMemoryError: Metaspace after several redeploys

By | May 26, 2017

There is an annoying issue with a Jboss EAP 7 Docker container I am using. After 3 deploys of my ear package I hit the “java.lang.OutOfMemoryError: Metaspace” issue. According to RedHat Solution 2038983 this is a known issue caused by: Root Cause The Metaspace is being exhausted. Either it is undersized, or there is a… Read More »

Debug tools for enterprise environments

By | February 8, 2017

There are various tools that I use to spot issues and investigate an enterprise environment. One of my favourite tools is IBM Performance Analysis Suite. Capabilities described by IBM: Import all kinds of performance data for analysis. Some examples: DB2 snapshot, Java verbose GC output, Java thread dumps. Import software/middle-ware configuration for compliance checking. Some… Read More »

Hibernate: Avoiding a “fake” exception: javax.persistence.TransactionRequiredException: Executing an update/delete query

By | October 21, 2017

I encountered some weird issue caused by the way Hibernate works. The exception messages returned by Hibernate are confusing as they are just a side-effect of the real issue. The code in question was something like that: In a manager bean we have the following: @Stateless(name = “ObjectManagerBean”, mappedName = “ObjectManagerBean/remote”) public class ObjectManagerBean …… Read More »