Administration Section
Or a bit of applied tetrisology. All that's new is well-forgotten old. Epigraphs. Problem statement It is necessary to periodically download the current PostgreSQL log file from AWS cloud to a local Linux host. Not in real-time, but let's say with a slight delay. The period for updating the log file is 5 minutes. The log file in AWS is rotated every hour. Tools used To download the log file to the host […]
Introduction to Operating Systems Hello, Habr! I would like to present to your attention a series of translated articles on literature that I find interesting — OSTEP. This material explores in depth the workings of Unix-like operating systems, specifically focusing on processes, various schedulers, memory, and other similar components that make up a modern OS. You can view the original materials here. […]
Logs are an important part of the system, enabling us to understand whether it is functioning as expected or not. In a microservices architecture, log management becomes a separate discipline akin to a special olympics. A multitude of questions must be resolved immediately: how to write logs from the application; where to write logs; how to deliver logs for storage and processing; how to process and store logs. The application of popular tools […]
The boy who created our website has already set up DDoS protection. Why did our site go down when we have DDoS protection? How many thousands does Qrator want? To properly answer such questions from clients or superiors, it would be wise to know what lies behind the term 'DDoS protection'. Choosing protection services resembles more of a doctor's choice of medication than choosing a table at IKEA. I […]
The fine for violating personal data laws can be up to 75,000 rubles. How can you protect yourself from violations when processing personal data? Have you complied with all legal requirements? As of July 1, 2017, fines have increased and now depend on the nature of the violations. Yes, a lot of time has passed, but, as often happens, especially in Russia, where […]
In my opinion, the theme of formal verification is insufficiently covered in the Russian-speaking segment of the internet, and there is a particular lack of simple and clear examples. I will provide such an example from a foreign source and supplement it with my own solution to the well-known problem of transporting a wolf, a goat, and cabbage across a river. But first, I will briefly describe what formal verification is and why […]
In this article, I will explain how to use Pinba together with ClickHouse and Grafana instead of pinba_engine and Pinboard. For PHP projects, Pinba is perhaps the only reliable way to understand what is happening with performance. However, Pinba is usually implemented only when there are already observed problems and it's unclear 'where to dig.' Often, no one has any idea how many times per second/minute […]
This is a short story from real practice where a minor issue, well disguised by redundancy, turns into a headache. A brief setup: A small branch with its own PBX (Asterisk + FreePBX) based on desktop hardware, along with a local terminal server running 1C, a file repository, and a virtual RO domain controller. Internet access is provided by Mikrotik. The branch is small, and this setup suffices for its needs. It all began […]
Here, posts are occasionally written about how people store and back up their photos — and just files in general. In the latest such post, I wrote a rather lengthy comment, thought a bit, and decided to expand it into a full post. Especially since I slightly changed my cloud backup method, which might be useful to someone. A home server where much of what is described takes place […]
For cooling in data centers, centralized multi-zone systems with water-cooled chillers are most commonly installed. They are more efficient than freon-based air conditioners because the coolant circulating between the external and internal units does not turn into a gas, and the compressor-condenser unit of the chiller only activates when the temperature rises to a certain level. One of the most critical issues when designing […]
And no one pours new wine into old wineskins; otherwise, the new wine will burst the skins, and it will spill, and the skins will be destroyed; but new wine must be put into fresh wineskins; then both are preserved. Luke 5:37,38 In April this year, the administration of the world's largest DC hub announced support for secure connections. Let's take a look at […]
It has been over two years since the last code review of the LLVM project using our PVS-Studio analyzer. Let's ensure that the PVS-Studio analyzer is still the leading tool for identifying bugs and potential vulnerabilities. To do this, we will check and find new errors in the LLVM 8.0.0 release. The article that needs to be written Honestly, I didn't want to write this article. […]