Administration Section
One day I accidentally came across some code that a user was trying to use to monitor RAM performance in their virtual machine. I won’t present the code (it's lengthy), but I'll leave only the most important parts. So, here’s the code! #include #include #include #define CNT 1024 #define SIZE (1024*1024) int main() { struct timeval start; struct timeval end; […]
Elasticsearch is a search engine with a JSON REST API that uses Lucene and is written in Java. A description of all the advantages of this engine is available on the official website. From now on, we will refer to Elasticsearch as ES. Such engines are used for complex searches in document databases, for example, searches that take language morphology into account or searches based on geo-coordinates. In this article, I […]
In the past year, there have been many leaks from Elasticsearch databases (see here, here, and here). In many cases, personal data was stored in the database. These leaks could have been avoided if administrators had taken the time to check a few simple settings after deploying the database. Today, we'll discuss those settings. For the record, we use Elasticsearch in our practice for log storage and analysis […]
There haven't been any reviews on Habr for "a faster alternative to Redis" — KeyDB. Having gained some fresh experience using it, I would like to fill this gap. The backstory is quite banal: during a significant traffic surge, we noticed a considerable degradation in application performance (specifically, in response times). At that time, unfortunately, we were unable to conduct a proper diagnosis of what was happening, so we planned a series of […]
When setting up a Kubernetes cluster, questions may arise: how many worker nodes to configure and what type? What’s better for an on-premise cluster: to buy several powerful servers or utilize a dozen old machines in your data center? And in the cloud, should you opt for eight single-core instances or two four-core instances? The answers to these questions are in the article by Daniel Weibel, a software engineer and instructor of the […]
Our team loves experiments. Each Slurm is not a static repetition of the previous ones, but rather an understanding of experience and a transition from good to better. However, with Slurm SRE, we decided to apply a completely new format — to provide participants with conditions as close as possible to 'combat' ones. To briefly outline what we did during the intensive session: 'We build, break, fix, and learn.' SRE is worth little […]
Hello, Habr users! In anticipation of the new enrollment for the course 'DevOps Practices and Tools', we have prepared a translation of interesting material for you. This article serves as a brief introduction to Loki. The Loki project is supported by Grafana and is aimed at centralized log collection (from servers or containers). The primary source of inspiration for Loki was Prometheus, with the idea of applying its approaches to log management: […]
Is it possible to survive using only the capabilities of TTY? Here’s my brief story about how I struggled with TTY, wanting to achieve normal functionality from it. Background Recently, on my old laptop, the graphics card failed. It failed so badly that I couldn't even start the installer for any OS. Windows crashed with errors while installing basic drivers. The installation of Linux was downright impossible […]
"Danger is my middle name," said Austin Powers, the man of mystery of international scale. But what is valued by superagents and intelligence agencies is not at all suitable for computer services, where boredom is much better than dangers. Istio, along with OpenShift and Kubernetes, turns the deployment of microservices into a truly dull and predictable affair — and that’s wonderful. This and […]
For some, Kim Dotcom, the founder of the infamous file-sharing site "MegaUpload," is a criminal and internet pirate; for others, he is an unyielding advocate for personal data privacy. On March 12, 2017, the world premiere of a documentary film took place, featuring interviews with politicians, journalists, and musicians who know Kim "from all sides." New Zealand director Annie Goldson uses footage from personal archives to tell […]
Hello, Habr. Recently, I shared my experience regarding the parameters we in the team most commonly use for Kafka Producer and Consumer to achieve guaranteed delivery. In this article, I want to explain how we organized the reprocessing of an event received from Kafka due to the temporary unavailability of an external system. Modern applications operate in a very complex environment. Business logic wrapped in […]
I would like to share my experience in merging networks in three geographically remote apartments, each using routers with OpenWRT as gateways, into a common network. When choosing between L3 routing of subnets and L2 bridging, where all nodes in the network will be in the same subnet, the preference was given to the latter method, which is more […]