Category Archives: DataCenter

Map #Docker container ports to virtual IPs in Linux with docker-compose

By | February 15, 2018

Sometimes you need to export multiple instances of the same service with a specific IP using same port outside of a docker swarm environment. Using docker swarm environment is easy to have several instances of the same service exporting some API on the same port. The swarm will take care of load balancing the services… Read More »

Automatic remote backup using cron and #OwnCloud

By | November 26, 2017

Setting up a backup is important and at the same time the most neglected task. One quick solution for a remote backup is using OwnCloud. If you already have your OwnCloud server or just an account the following short steps can be done. STEP 1: Gather your data Lets gather the data to be back-ed… Read More »

#Websphere SIB issues when running Websphere in a #Docker container

By | November 14, 2017

When running a Websphere Application server instance in a docker container, if the Service Integration Bus (SIB) is defined to store all the messages and data in an external database there is an issue caused by the way the bus is created. When the SIB is initialized the given name depends on the hostname of… Read More »

Bind #Docker container ports to virtual interfaces to simulate cluster nodes

By | November 8, 2017

My setup implies that I have 3 almost identical application nodes (running as containers) that are part of a cluster and they need to be mapped to different external IPs (not part of the docker ingress network) because they are added in a cluster configuration external to docker. The default behavior of port binding is… Read More »

TCP keepalive: what is it, why do you need it, how to configure it on #Linux

By | November 7, 2017

As you are aware, no service runs alone on some server. You always have to take into account the communication layer between your server and client services. One of the most tricky thing a lot of people overlook is the “housekeeping” of the communication layer. In a properly setup enterprise environment your communication layer (firewalls,… Read More »

#Windows10 – set English language but with German keyboard layout

By | October 21, 2017

I have a nice mechanical keyboard “VicTsing® Mechanical PC Gaming Keyboard 87” with German layout, but I prefer my Windows 10 in English. The quick solution the use the keyboard was to add also German language support but kept English as default language. Then the most annoying and frustrating thing kept happening: 1. I selected… Read More »

Back-up of /home of a running system using lv snapshot

By | October 21, 2017

Following is a simple and easy way to do a consistent back-up of the /home directory (usually mounted in a separate partition) on a running system. We do not have the luxury of being able to stop the operations of a server and unmount the home partition to make sure no changes are done during… Read More »

Find in Linux if your installed RAM is ECC

By | October 21, 2017

Sometimes really simple questions are hard to answer. One day I got the question from a coworker: “How do I know if some installed RAM is ECC or not”. The easiest way is to use dmidecode command that dumps in Linux all the system characteristics. But because I had no idea how to see if… Read More »

#Docker : Fix services cannot see each other by name if they run on different swarm nodes issue

By | October 18, 2017

Lately after one of the updates of docker binaries I started to have a strange issue in a Docker Swarm setup configured here. Services were no longer able to see each other if they were running on different nodes. If two services were running on the same swarm node there was no issue. This is… Read More »