Postgres-BDR +  To achieve fault tolerance, you need redundant systems. There are two basic approaches to redundancy, active-standby or active-active. Active-standby Active-standby means that in the event of failure of the active node, a failover to a standby node is carried out. Active-active Active-active means that all nodes are continuously active. In the event of failure of a node, that node simply stops being used and the other nodes assume the full load. The problem with active-standby Active-standby has a huge problem in the real world – at the time when a node fails, the chances of failover occurring smoothly are hugely reduced since that the problem that caused the failure is quite likely to affect the system’s ability to failover smoothly – in other words, when things are[…]

Overview: We recently carried out a short introductory Docker workshop, starting from scratch, installing Docker and taking it through to the point where a software stack, consisting of several linked containers, are deployed using docker-compose. Here’s what we covered. Docker concepts: Docker containers are easy-to-deploy units of software, analogous to ¬†the shipping containers used by the transport industry, which simplifies the job of shipping diverse goods around the world. Docker images are the templates for the containers. Every Docker container is started from an image. Images are defined by a Dockerfile¬†which contains instructions for building the image, based on an existing image (for for instance, a web-server image will be based on an OS image, simply adding a layer of[…]