Monthly Archives: March 2019

Redis: replication, part 2 – Master-Slave replication, and Redis Sentinel

29 March 2019
 

 The first part – Redis: replication, part 1 – overview. Replication vs Sharding. Sentinel vs Cluster. Redis topology. The next part – Redis: replication, part 3 redis-py and work with Redis Sentinel from Python. The whole story was started when we decided to get rid of memcached. Currently, we have memcahced and Redis running on… Read More »

Redis: replication, part 1 – an overview. Replication vs Sharding. Sentinel vs Cluster. Redis topology.

29 March 2019
 

 CodeProject Initially, it was planned to write one small post with an example how to create a Redis replication but as I read more and more details – I wanted to describe more and more about it, so eventually I split this post into two parts. In this one – some quick overview, a brief… Read More »

Kubernetes: running Minikube on Arch Linux

27 March 2019
 

 Minikube – a utility to run a Kubernetes cluster locally on your PC. It can use Virtualbox, VMware, Hyper-V etc hypervisors which will be used to create a virtual machine with a Kubernetes cluster. Minikube is a great tool for developers or DevOps engineers to test deployments/services etc without the need to create and configure… Read More »

Prometheus: Alertmanager’s alerts receivers and routing based on severity level and tags

26 March 2019
 

 We have three working environments – Dev, Stage, Production. Also, there are a bunch of alerts with different severities – info, warning и critical. For example: … – name: SSLexpiry.rules rules: – alert: SSLCertExpiring30days expr: probe_ssl_earliest_cert_expiry{job=”blackbox”} – time() < 86400 * 30 for: 10m labels: severity: info annotations: summary: “SSL certificate warning” description: “SSL certificate… Read More »

Prometheus: Alertmanager – send alerts to a “/dev/null”

26 March 2019
 

 In addition to the Prometheus: Alertmanager’s alerts receivers and routing based on severity level and tags post. Have an Alertmanager config with routes. The task is – send all alerts from a Dev-environment into a “/dev/null”. To do this – create an empty receiver: … receivers: – name: ‘blackhole’ – name: ‘default’ slack_configs: – send_resolved:… Read More »

What is: chroot – system call and utility in Linux

23 March 2019
 

 chroot() was added to the Version 7 Unix in 1979 and used for filesystem isolation. In fact, it’s the predecessor of the whole current containerization idea, just now there are namespaces and cgroups are used while earlier chroot was used to create an environment which is isolated from a host and can be used for… Read More »

TestRail: QA Test Case Management installation on Linux

22 March 2019
 

 TestRail – Test Case Management Software for QA and Development Teams. Well – that’s all needed as a description) Below – its installation on Debian Linux with NGINX, Let’s Encrypt, PHP-FPM, MariaDB, and Exim. Project’s homepage – www.gurock.com/testrail Installation official documentation – here>>>. Setup will be on an AWS EC2. LEMP and SSL Login to… Read More »