The issue of making a correct evaluation of a web site is one that should be addressed by any site owner at some point. The most important metrics of a web site that are a must will be discussed bellow. SECURITY I do not know how to stress the importance of this metric. This is… Read More »
There is a very simple way to save a pdf presentation to individual jpeg images of the slides using convert. convert -density 300 presentation.pdf presentation_page_%04d.jpg where: – density 300 specifies the DPI used to read the pdf. – presentation_page_%04d.jpg is a name pattern for the saved images As a result if presentation has 20 slides… Read More »
There is an annoying issue with a Jboss EAP 7 Docker container I am using. After 3 deploys of my ear package I hit the “java.lang.OutOfMemoryError: Metaspace” issue. According to RedHat Solution 2038983 this is a known issue caused by: Root Cause The Metaspace is being exhausted. Either it is undersized, or there is a… Read More »
It seems that now I have a name for what I have doing for the last 15 years 🙂 I attended a a DevTalks conference and the hype of the day was the DevOps idea. According to the wiki definition: DevOps (a clipped compound of “software DEVelopment” and “information technology OPerationS”) is a term used… Read More »
A very important release announced in a post on the Oracle blog. Java SE support for Docker CPU and memory limits In short: “As of Java SE 8u131, and in JDK 9, the JVM is Docker-aware with respect to Docker CPU limits transparently.” SET 1: If -XX:ParalllelGCThreads, or -XX:CICompilerCount are not specified as command line… Read More »
The number of uses and posts related to Docker is huge. The problem is the clutter is also big so finding the relevant posts is hard. Bellow is a selection of posts that got my attention. First I have to mention the official Docker blog where the curated list of posts about docker are posted… Read More »
I have a RHEL 6 Linux cluster setup where the main database storage is replicated on a remote site using DRBD. In case of a failure of the primary site the decision is taken to move operations on the remote site. When the production site is back online sometimes the administrator is too eager to… Read More »
In a Linux HA cluster setup on RHEL 6 that involves replication between sites using DRBD suddenly after reboot of one of the nodes it was imposible to start any cluster service from that node. Surprinsingly there was no issue to do so from the other node. While looking in the /var/log/messages on the affected… Read More »
I started from a great post Monitoring your Ubiquiti home-network with a Docker LibreNMS and SNMP, to make my own network monitor where to gather all the network devices SNMP messages. Because I like docker compose files to start up all my components and I want to use a separate docker mysql I made the… Read More »
In the following I am trying to create a Jboss EAP docker image with up-to-date patches and configurations applied using JBoss CLI. With this template I can then very easy setup any complex JBoss based application environment with ready defined data sources, connectors , resource adapters etc. In the following I will describe the steps… Read More »