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.

Terraform: creating an AWS OpenSearch Service cluster and users

18 September 2025
 

  In the first part, we covered the basics of AWS OpenSearch Service in general and the types of instances for Data Nodes – AWS: Getting Started with OpenSearch Service as a Vector Store. In the second part, we covered access, AWS: Creating an OpenSearch Service Cluster and Configuring Authentication and Authorization. Now let’s write… Read More »

AWS: creating an OpenSearch Service cluster and configuring authentication and authorization

15 September 2025
 

  In the previous part, AWS: Getting Started with OpenSearch Service as a Vector Store, we looked at AWS OpenSearch Service in general, figured out how data is organized in it, what shards and nodes are, and what types of instances we actually need for data nodes. The next step is to create a cluster… Read More »

PostgreSQL: using EXPLAIN and setting up “auto_explain” in AWS RDS

12 February 2025
 

  I have already mentioned the EXPLAIN feature in the PostgreSQL: AWS RDS Performance and monitoring blog post, but this is such an interesting and useful thing that it’s worth talking about it separately. In addition, AWS RDS for PostgreSQL has the ability to enable Execution Plans logging with EXPLAIN, which is also useful for… Read More »

PostgreSQL: AWS RDS Performance and monitoring

10 February 2025
 

  We are migrating our Backend API from DynamoDB to AWS RDS PostgreSQL, and several times RDS crashed. Actually, given that we took db.t3.small with two vCPUs and two gigabytes of memory to save money, it was quite expected, but I wondered why everything was crashing. A few days later, I started to debug the… Read More »

AWS: RDS IAM database authentication, EKS Pod Identities, and Terraform

7 July 2024
 

  We’re preparing to migrate our Backend API database from DynamoDB to AWS RDS with PostgreSQL, and finally decided to try out AWS RDS IAM database authentication, which appeared in 2021. IAM database authentication, as the name implies, allows us to authenticate to RDS using AWS IAM instead of the login-password from the database server… Read More »

Apache Druid: PostgreSQL as Metadata storage, and replace ZooKeeper with Kubernetes Extensions

5 October 2022
 

  We continue with a series of posts about Apache Druid. In the first part, we took a look at the Apache Druid itself – its architecture and monitoring, in the second part – we ran a PostgreSQL cluster and set up its monitoring. Next tasks: switch Druid to PostgreSQL as metadata storage instead of Apache Derby… Read More »

PostgreSQL: PostgreSQL Operator for Kubernetes, and its Prometheus monitoring

23 September 2022
 

  So, we’ve launched Druid, see Apache Druid: Overview, Running in Kubernetes, and Monitoring with Prometheus . So far, a local Apache Derby database is used as the default storage for metadata . Next, we will switch Druid to PostgreSQL, and later we will remove ZooKeeper from the cluster setup. To begin with, let’s start a PostgreSQL cluster in Kubernetes,… Read More »

Apache Druid: overview, running in Kubernetes and monitoring with Prometheus

18 September 2022
 

 Apache Druid is a columnar database, focused on working with large amounts of data, combining the features and benefits of Time-Series Database, Data Warehouse, and a search engine. The general task is to set up monitoring of the Druid cluster in Kubernetes, so at first, we will see what it is in general and how… Read More »

Elastic Stack: an overview and ELK installation on Ubuntu 20.04

22 February 2022
 

 The last time I’ve worked with the ELK stack about 7 years ago, see the ELK: установка Elasticsearch+Logstash+Kibana на CentOS. Currently, we are using Logz.io, but its costs going higher and higher, so we started looking at the self-hosted ELK solution to be running on our AWS Elastic Kubernetes Service clusters. So, the task, for… Read More »