Category Archives: Databases

A NoSQL database provides a mechanism for storage and retrieval of data that is modeled in means other than the tabular relations used in relational databases.
A relational database management system is a database management system based on the relational model of data.

Kubernetes: running SQL migrations with Kubernetes Job and Helm hook

27 October 2020
 

 We have a project running in Kubernetes that needs to run SQL migrations during deployment. To run migrations need to clone a Github repository and run actually migrations stored in it. Currently, this is done with Kubernetes initContainers , and there are two of them – the first one with git clones the repository with… Read More »

Redis: running Master-Slave replication in Kubernetes

29 September 2020
 

 The task is to spin up a Redis instance in a Kubernetes cluster. Will use the Master-Slave replication setup with Sentinels for monitoring and failover operations. Check the Redis: replication, part 2 – Master-Slave replication, and Redis Sentinel post for more details. Redis cluster vs Redis replication See Redis: replication, part 1 – an overview.… Read More »

AWS Elastic Kubernetes Service: load-testing and high-load tuning – problems and solutions

4 September 2020
 

 Actually, this post was planned as a short note about using NodeAffinity for Kubernetes Pod: But then, as often happens, after starting writing about one thing, I faced another, and then another one, and as a result – I made this long-read post about Kubernetes load-testing. So, I’ve started about NodeAffinity, but then wondered how… Read More »

Redis: “psync scheduled to be closed ASAP for overcoming of output buffer limits” and the client-output-buffer-limit

26 February 2020
 

 We have a Redis-cluster with Master-slave replication and Sentinel, see the Redis: replication, part 2 – Master-Slave replication, and Redis Sentinel, Redis: fork – Cannot allocate memory, Linux, virtual memory and vm.overcommit_memory, and Redis: main configuration parameters and performance tuning overview posts. The system worked great until we started using it much more actively. Redis… Read More »

Chromium: Linux, keyrings && Secret Service, passwords encryption and store

10 December 2019
 

 One of the motives to go deeper into the keyrings (see the What is: Linux keyring, gnome-keyring, Secret Service, and D-Bus post) was the fact that Chromium, surprise-surprise, keep passwords unencrypted if a Linux system has no keyring and/or Secret Service enabled. So, let’s try to find how and where Chromium store passwords, and the… Read More »

Nextcloud: running in Docker Compose on Debian with Let’s Encrypt SSL

30 November 2019
 

 I while ago I’d tested the Nextcloud, see the NextCloud: installing server on Debian behind NGINX with PHP-FPM and client on Arch Linux post. In general, it looks good, so it’s time to try to run in a production environment and finally migrate from Dropbox to it. Today, let’s spin up a Nextcloud instance using… Read More »

AWS: RDS Certificate Authority SSL certificate upgrade

22 November 2019
 

 We started receiving emails from AWS with notifications to update RDS Certificate Authority certificates. It’s time to do it, so let’s start from our Dev, then will repeat on Staging and Production environments. W eare using common AWS RDS MariaDB instances, and the upgrade documentation is available here>>>. The process itself is really simple and… Read More »

AWS: Redshift – quick start and SQL-workbench connection config

18 October 2019
 

 Our data-analytics team eventually started to play with an AWS Redshift cluster instead of the MariaDB RDS service. Actually, the current task is to spin up a simple Proof of Concept Redshift’s cluster in the AWS. Let’s do it quickly, without details – if this will go to the Production, I’ll add another post with… Read More »