Java EE: Make an @Entity “empty” using a @Transient proxy

By | February 8, 2017

In some cases while optimizing code to minimize the database footprint of a Java EE application we get to the point of trying to get rid of duplicate data. In a lot of cases several steps of the processing flow tend to store partially processed data or states of data and in a lot of… 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 »

DB2: SQL Error: -803, SQLState: 23505 due to NON-UTF8 character in parameter

By | October 24, 2017

Sometimes Java and databases do not use the same standards to represent data. This can lead to strange exceptions for which sometimes can be hard to pin point the cause. We have the following Exception reported in the enterprise application log. Let’s analyse the errors. [7/13/16 12:46:32:752 IST] 00001456 SqlExceptionH Z org.hibernate.engine.jdbc.spi.SqlExceptionHelper logExceptions SQL Error:… Read More »

Change Parameters of Windows Fail-Over Cluster with PowerShell

By | February 8, 2017

Configurations of a Windows Fail Over Cluster can be done entirely from the GUI but as we know this is valid for the simple setup. The GUI is limited to the easy cases, not for more uncommon cases. I already covered the case of the Active Directory Detached Cluster that can be created only using… Read More »

Linux: How to remote desktop to Fedora Linux from a Windows 10

By | March 2, 2018

After connecting my two sites using IPSEC see ipsec site-to-site with virtual tunnel interface/ it is easy to ssh to the remote site and OpenVPN see OpenVPN site to site Let us go a step further and activate also remote desktop. I want to be able to connect from my Linux machines but also from… Read More »

DB2 : Claim back space from dropped tables

By | February 8, 2017

Especially when creating a demo image of an enterprise system we want to have a smaller footprint than the full system that was cloned. The same is true when the image is used for volume benchmarks. Between different benchmark sessions we want to clean the old test data and maybe in the end we want… Read More »

Server Rack: Create your own low-cost rack console

By | March 1, 2017

Because the number of my systems increased moving all my stuff to a rack was the right decision to avoid cable spaghetti and administration hell. But when you have a rack you need to have an administration console for it. Looking on the market (the deals market) the cheapest console I could find was some… Read More »

Change HP ILO settings without server restart

By | May 26, 2017

I was relocating my servers in a new rack and configuration and decided to put all my ILO ports to a different router with no DHCP. Obviously I ended up with some fake IP6 address defaulted to the ILO device. To make the changes to ILO without a server reboot we have the nice hponcfg… Read More »

EdgeRouter: Routing through OpenVPN and IPSEC with OSPF

By | May 9, 2016

Open Shortest Path First (OSPF) is a routing protocol for Internet Protocol (IP) networks. Because I have site-to-site OpenVPN and IPSEC tunnels between my primary and remote sites I ended up defining lots of static routes. The environment started to be complex enough to justify the use of OSPF that is supported by EdgeRouter. The… Read More »

EdgeRouter: IPSEC site-to-site with Virtual Tunnel Interface

By | February 27, 2019

The following are the steps I used to perform to set up an IPSEC VPN with a vti (virtual tunnel interface). The advantage is that using a vti gives us a route-able interface so making it easy to work with the IPSEC tunnel. The current setup looks like: Primary Site: ER-8 (with load-balancing WAN1 and… Read More »