Author Archives: George Valentin Voina

A.I. : State-of-the-art of Computer Vision

By | January 5, 2017

In another life (almost 14 years ago) for some years I had the privilege to be a member of one of the top European computer vision groups VISICS/PSI VISICS/PSI. My focus then was object categorization using neural networks, not a very popular topic at that time due to limitations in data availability and computation power.… Read More »

DB2 : Errors when a database nickname or view is no longer available

By | February 8, 2017

In an enterprise application based on hibernate running over DB2 we have to refer with several views and nicknames to external tables. This can be the case when SSO is used or there are some common static data (accounts, user entries, financial constants etc. ) that are kept in a centralized database repository and are… Read More »

EdgeRouter: UBNT releases fix for firmware 1.9 that broke my l2tp/ipsec

By | December 31, 2016

That warm feeling that you contributed to the community when you find your bug report in an official release notes 🙂 There is a new firmware release EdgeRouter ER-8/ERPro-8/EP-R8: Firmware v1.9.1 that reports as fixed an issue first reported by me for the 1.9 firmware. The issue was reported in the thread Update to 1.9… Read More »

Blog Links: DMARC (Domain-based Message Authentication, Reporting & Conformance)

By | December 28, 2016

Yet another acronym, DMARC (Domain-based Message Authentication, Reporting & Conformance). This became very important due to the high-profile phishing done by russian state sponsored hacking groups involving spoofed e-mail addresses. By sending e-mails that looked as coming from credible sources they were able to infect systems connected to political entities: Clinton campaign staff, democrat party… Read More »

#DRBD: Synchronization of sites after the failed DR (disaster recovery) site is recovered

By | April 24, 2017

This is a follow-up tutorial on the DRBD replication posts about resynchronization of sites after the failed DR site is recovered. More than a year ago I described in a long tutorial how to use DRBD in a real production environment and the challenges associated to it. See: DRBD based disk replication of a production… Read More »

#DRBD: Resynchronization of sites after the failed PR site is recovered (DRBD split brain recovery)

By | March 6, 2017

This is a follow-up tutorial on the DRBD replication posts about resynchronization of sites after the failed PR site is recovered (DRBD split brain recovery). More than a year ago I described in a long tutorial how to use DRBD in a real production environment and the challenges associated to it. See: DRBD based disk… Read More »

#DRBD: Promoting the DR site as the main site when PR is failed

By | March 6, 2017

This is a follow up tutorial on the DRBD replication posts about promoting the DR site as the main site when PR is failed. More than a year ago I described in a long tutorial how to use DRBD in a real production environment and the challenges associated to it. See: DRBD based disk replication… Read More »

#DRBD: Gracious role switching of live sites configured with DRBD replication

By | March 6, 2017

This is a follow up tutorial on the DRBD replication posts about gracious role switching of live sites configured with DRBD replication. More than a year ago I described in a long tutorial how to use DRBD in a real production environment and the challenges associated to it. See: DRBD based disk replication of a… Read More »

Blog links: How to choose your database technology

By | January 12, 2017

The following is a very interesting post about different database technologies and when to use them. It is a good way read that helps you to explain to people that you do not have to use some DB tech only because is the new cool boardroom word 🙂 When to use Cassandra, MongoDB, HBase, Accumulo… Read More »