Administration Section
How to understand whether you need Docker instead of a VM? You need to determine what exactly you want to isolate. If you need to isolate a system with guaranteed allocated resources and virtual hardware, then you should choose a VM. If you need to isolate running applications as separate processes in the system, you'll need Docker. So what is the difference between Docker containers and VMs? Virtual [...]
For over 20 years, we have been viewing web pages using the HTTP protocol. Most users don't even think about what it is and how it works. Others know that somewhere beneath HTTP is TLS, and beneath that is TCP, and beneath that, IP, and so on. And then there are the heretics who believe that TCP is a thing of the past, […]
So, you're collecting metrics. Like us. We are also collecting metrics. Of course, those necessary for business. Today, we will talk about the very first link in our monitoring system — the statsd-compatible aggregation server bioyino, why we wrote it, and why we abandoned brubeck. In our previous articles (1, 2), you can learn that for some time we collected tags […]
Hello everyone! In my last article, I wrote about organizing a modular monitoring system for microservice architecture. Nothing stands still; our project is constantly growing, and the number of stored metrics is also increasing. How we organized the transition from Graphite+Whisper to Graphite+ClickHouse under high loads, our expectations from it, and the results of the migration can be found below. Before […]
Today, our project operates dozens of microservices alongside monolithic code. Each of them requires monitoring. Managing this with DevOps engineers alone is challenging. We have developed a monitoring system that works as a service for developers. They can independently write metrics to the monitoring system, use them, build dashboards based on them, and attach alerts to them, […]
Last time we discussed the features of the new NB-IoT standard from the perspective of radio access network architecture. Today, let’s explore what has changed in the core network with NB-IoT. So, let's go. Significant changes have occurred in the core network. First, a new element has been introduced, as well as a series of mechanisms defined by the standard as 'CIoT EPS Optimization' or optimization […]
In the article 'NB-IoT: How It Works? Part 2', while discussing the architecture of the NB-IoT core network, we mentioned the introduction of the new SCEF node. In this third part, we explain what it is and why it is needed. When creating M2M services, application developers face the following questions: how to identify devices; what algorithm to use for authentication and confirmation; which one to choose […]
In August 2019, Russia executed the world's first commercial project for wireless backup of a trunk optical cable with a capacity of 40 Gbps. The operator 'Yedinstvo', a subsidiary of Norilsk Nickel, used such a channel to establish an 11-kilometer wireless backup across the Yenisei River. Periodically, articles about world records in wireless communication appear in the press, including on Habr. […]
Trendy technological services are changing our internet habits. I love files. I enjoy renaming them, moving them, sorting them, changing their display in folders, creating backups, uploading them to the internet, restoring, copying, and even defragmenting them. As a metaphor for how to store a block of information, I think they are magnificent. I like the file as a whole. If I need to write an article, it […]
I am a system administrator at FirstVDS, and this is the text of the first introductory lecture from my short course aimed at helping new colleagues. Specialists who have recently started their journey in system administration face a number of common issues. To offer solutions, I decided to write this series of lectures. Some aspects are specific to hosting technical support, but overall, they might […]
Currently, many projects are being launched aimed at replacing existing information security tools. This is unsurprising, as attacks are becoming increasingly sophisticated, and many security measures can no longer provide an adequate level of protection. Throughout these projects, various challenges arise—finding suitable solutions, trying to stay within budget, procurement, and the actual migration to new solutions. Within […]
The ability to downgrade devices running RouterOS (Mikrotik) remotely poses a threat to hundreds of thousands of network devices. The vulnerability is related to DNS cache poisoning of the Winbox protocol and allows for loading outdated (with the password reset to 'default') or modified firmware onto the device. Details of the vulnerability The RouterOS terminal supports the resolution command for DNS queries. This request is processed by a binary file named resolver. The resolver is […]