I like when solutions you are excited about and are first seen as “experimental” start to go mainstream. This happened with containers (Docker, CoreOS, Kubernetes etc.) which are now the hottest topic in DevOps right now. The same is happening now for Apache Kafka which was adopted by no other than “Goldman Sachs” for their… Read More: #Apache #Kafka solutions going mainstream »
This is a common issue in the new Linux kernels discussed on many forum threads. There is a long thread here about this problem. In short the issue is that when you run out of memory “kswapd0” a kernel process than manages virtual memory will start moving “old memory entries” to swap. The “run out… Read More: A solution for kswapd0 going haywire on #Linux »
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: Map #Docker container ports to virtual IPs in Linux with… »
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: Automatic remote backup using cron and #OwnCloud »
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: #Websphere SIB issues when running Websphere in a #Docker container »
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: Bind #Docker container ports to virtual interfaces to simulate cluster… »
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: TCP keepalive: what is it, why do you need it,… »
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: #Windows10 – set English language but with German keyboard layout »
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: Back-up of /home of a running system using lv snapshot »
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: Find in Linux if your installed RAM is ECC »