Hibernate: Optimize updates with @DynamicUpdate

By | June 29, 2018

When using Hibernate as a layer between your Java code and the Database layer you release control on how the actual SQL query is generated. Hibernate will generate from the HSQL you write the “best” query. That “best” is in fact sometimes sub-optimal. A very important Hibernate 4 (make sure you have at least 4.2.5)… Read More »

ILO: Get the ILO IP from a Linux host server

By | December 4, 2016

In case your HP ILO is set to DHCP there is the need to find out what is the allocated IP in case you do not have access to the cosole. The easiest way is to use ipmi tools. STEP 1 : Install ipmi tools # dnf install ipmitools STEP 2: Load the ipmi kernel… Read More »

Apache: How to use reverse secure proxy to chain secure apache servers – updated

By | May 26, 2017

On the site I host my services I have only one IP from the ISP and naturally a single 443 port to server https requests. If you have to host multiple sites behind that you can do it very easy with apache. You just have to define Virtual hosts for each different site. Define a… Read More »

IT Traveller: Failed airport technology

By | March 11, 2017

I travel quite often across the world for job related purposes. Being an IT guy that does servers installations, develops and deploys enterprise software across the world I am always noticing everyting that is IT related. It is always fun to see failed tech in airports I transit or in hotels where I stay. Failed… Read More »

Datacenter: Recover Owncloud and WordPress from a Cold Backup

By | February 9, 2017

Sometimes you test your best practice procedures the hard way. A failure that messed up with my grub (yes you can manage to break grub even in a RAID1 setup) followed by a failed Fedora update forced me to do a clean Fedora 25 installation. STEP 1: Cold Backup of all partitions of interest Because… Read More »

Blog Links: Java Links

By | November 30, 2016

Keeping pace with new stuff related to programming and IT world is hard enough that you have to make a list from time to time of stuff you have in the backlog. Here is a list of new things I find to be very interesting: The November/December edition of Java Magazine Online is released Java… Read More »

Security: Generate certificates with keytool

By | November 23, 2016

The following is an example on how to generate a certificate directly on a Linux server using keytool, then sign it by a windows CA. The example assumes we are regenerating a certificate for a glasfish domain. STEP 1: Delete the old certificate In glasfish in each domain where security is activated we have a… Read More »

DataCenter: Setup the HP ILO device

By | November 17, 2016

In an enterprise environment consisting of several HP ProLiant servers it is important to set up for each of the servers the IPs of the associated ILO4 devices. This is an important step as this ILO devices are going to be used for the cluster fencing or access from the service network. To set-up the… Read More »

Oracle: Reactivate a database user

By | February 8, 2017

I am always very annoyed when my Oracle user is automatically expired and locked. This is done automatically at 180 days in some installations. The following are some very easy steps for a question that everybody is asking again and again on forums. STEP 1: Connect to the DB sqlplus / as sysdba STEP 2:… Read More »