Category Archives: Programming

Learning GO: Obtaining a unique sequence from #PostgresSQL with #golang

By | May 21, 2018

At some point I discovered GO trying to do very simple and fast code for specific tasks without having to load lots of libraries, deploy application servers or set up complicated frameworks. If you want to build fast very small native micro-services that can be deployed in a docker instance < 10MB Go is the… 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 »

DB2: SQL Error: -803, SQLState: 23505, Unique Constraint Violation

By | December 8, 2019

Yet another thread of DB2 errors from an EJB application that connects to a DB2 instance. The reported thread of errors: [7/13/16 12:46:38:670 IST] 00000098 SqlExceptionH Z org.hibernate.engine.jdbc.spi.SqlExceptionHelper logExceptions [jcc][t4][102][10040][4.19.26] Batch failure. The batch was submitted, but at least one exception occurred on an individual member of the batch. Use getNextException() to retrieve the exceptions… Read More »