25. 02. 2022.

Redis performance tuning – Top 10 mistakes

Redis is the most popular Key-value data store and one of the most popular database systems overall.   According to Db-engine ranking: https://db-engines.com/en/ranking/key-value+store (You can check the picture below), Redis is on the top position by large margin among Key-values data stores. Amazon DynamoDb on the second place, lags behind Redis more than a twice. […]

10. 02. 2021.

Dockly -Swiss army knife for managing Docker containers without Kubernetes

These days more and more vendors embrace Docker containers as preferable way of software distribution. In many cases you don’t need to deal with all the complexities that comes with Kubernetes orchestration. Instead you just want to have a simple tool which provides a full control and visibility over what is going on in containers […]

21. 01. 2021.

Kafka & TCP Retrans Error rate

Recently I had an interesting case where in the data pipeline I’ve found duplicate messages in the Kafka topics. Duplicate records in Kafka topics might appear for many different reasons, but most of them you can find only those related to the Kafka settings (especially those related to the Kafka settings). In this article you […]

06. 12. 2020.

Bashtop – future of the terminal Linux monitoring

Although the idea of the original top utility is follewed in many similar utilities for terminal based Linux monitoring, till now I’ve been using Htop, atop (which can monitor GPU on top of CPU/Mem/Net/Disk) and Nmon to do a job (later one, called „Topas on steroids” is ported from AIX to Linux). Quite recently I’ve […]

20. 11. 2019.

How to install Oracle SQL Developer Data Modeler 19.2 on Ubuntu 18.04 LTS

One of the main reasons why I choose Fedora as my main operating system is due to Oracle dependency on rpm package manager and because of the bleeding edge of Open Source technology like the latest kernel version, compilers, new drivers etc. Unfortunately, very often bleeding edge means bloody edge as I have to spend […]

07. 10. 2019.

Installing Oracle database on Amazon AWS

Although you can use AWS RDS service which offers PaaS architectural model of running Oracle database on top of AWS Cloud, due to many limitations (installation type, options selected etc.), many enterprises still prefer using IaaS model, where such restrictions does not exist (e.g. you can install Enterprise Edition of Oracle database, RAC, Data Guard […]

02. 09. 2019.

Cloning larger bootable HDD into a smaller one

This article is triggered by the real case when I have not only to clone larger (external) disk into a smaller one, but to keep cloned disk bootable as it’s source. The article is mainly reminder what I need to do, as I frequently need to prepare PoC (Proof of Concept) that requires to run […]

28. 08. 2019.

Installing Ubuntu on an external bootable HDD

In case you need to experiment with different OS from one that you already have installed, but don’t want to take a dual-boot approach to avoid possible corruption of your main disk, then keep reading this article – Installing Ubuntu on an external bootable HDD.   Although it is possible to run Linux along with […]

22. 07. 2019.

Oracle database benchmarking by using CALIBRATE_IO

CALIBRATE_IO is yet another popular database simulation/stress test utility, mainly used to perform IO benchmarks.   Procedure, that is part of DBMS_RESOURCE_MANAGER package, will generate read-only workload made up of 1 MB of random of I/Os to the database to determine the maximum number of IOPS and MB per second. You can save the following […]

17. 07. 2019.

Implement High Performance Computing tools to test cluster stability

There are many benchmark testing tools that are focusing on various fields of a cluster like computing capabilities, energy efficiency, data & storage, memory etc. In this article I’m going to use Somberero – High Performance Computing tool suitable to run a test against your home PC or cluster of supercomputers. Sombrero is particularly useful […]