2023 – год нейронок и раскола в мире русского IT.

В этом году я сделал хорошее вложение в музыкальное хобби, собрав все необходимое оборудование, нужное для записи по крайней мере качественной музыки.

Прочитал кучу технической литературы, выучил пару новых языков программирования и один из них даже начал активно применять в работе. В следующем году хотелось бы уделить больше внимания именно художественной литературе. В этом году игра и вселенная Atomic Heart вообще была для меня большим открытием как и книга Предыстория «Предприятия 3826»

Еще мне удалось завершить цикл прохождения всей серии игр Resident Evil (включая ремейки). Буквально пару лет мне понадобилось для этого. Это около 25 игр.

Ну и конечно уходят в историю мои самые сложные два года жизни. Дети начали спать по ночам, больше я по ночам не просыпаюсь по 2-3 раза.

Желаю всем хорошего Нового Года. Надеюсь все задуманное у всех сбылось.

У меня сбылось

In the world of software development, although probably in any other too, there is an interesting phenomenon. Specialists are divided into two types: the performer and the teacher.

The performer (inventor) – who writes a lot, practices, makes mistakes, draws conclusions, and constantly improves their professional hard skills.

The teacher – who theorizes a lot, writes little, constantly thinks about different algorithms, can take months for one seemingly simple task but without noticeable results.

Teachers are also needed, they fit perfectly into a position not really related to actual development.

I’ve started learning a new programming language Rust. This language is often used for system programming or creating high-performance applications.

While learning, I’m working on my pet project on GitHub, which includes integration with OpenAI (ChatGPT) and TTS service. I’m planning to integrate it with some AI for image generation (like dreamstudio.ai).

I also had to write a small Python script using FastAPI and Silero AI for TTS requests. The bot can answer in voice, reading responses from ChatGPT. For this, I had to set up a separate service.

This pet project has already proved to be helpful in my daily work. It helped me create a well-written profile page for GitHub and endlessly answered my questions about learning Rust.

By the way, I also generated the preview for this post on dreamstudio.ai.

This pet project has already proven itself well. It helps me in my daily work, it helped me to create a proper profile page for Github and endlessly answers my questions about learning Rust.

By the way, I also generated the preview for this post on dreamstudio.ai.

I needed to extract certain metrics for events from the Node.js application. For example, increment the metric in case of a successful response, and so on.

I had Zabbix and Grafana at my disposal.

It turned out that there is a prom-client module for Node.js that can export metrics, but the problem is – like other modules, it does not work with pm2.

The problem is that a metric collected in one process cannot be correctly received in another process, which is responsible for providing the metric to the zabix agent through http.

We fix the omission: pm2-prom-client

The module is basically for Prometheus, but it also suits us.

Its essence boils down to transmitting the metrics on the pm2 bus to the agent process with subsequent export in plain-text or JSON.

Today we will talk about zero downtime deployment in a Node.js application.

To make this possible, your application must be running in a child process. For example, use PM2 or ts-node-dev.

The first thing we need to do is to indicate that a new (deployed) process is ready to take over the work of the redeployed application. To do this, you need to call…

process.send(“ready”)

In your application, after all the necessary dependencies are in the ready state, such as a successful connection to the database.

Also, in our application, we need to add logic for the completion of all current operations when receiving a termination signal (SIGINT).

process.on(“SIGINT”, () => {
  this.connection.close(); // For example, we will close the current connection to AMQP and stop accepting new messages.
  setTimeout(() => {
    process.exit()
  }, 5000) // Let's wait for 5 seconds until the current processes are completed.
})

When running such an application, for example, using ts-node-dev, you may notice that after pressing control+c, the application does not terminate immediately, but after 5 seconds.

What will happen:

• The new application launched in a child process starts and reports “ready”, after which it begins its business logic.
• At the same time, a SIGINT signal is sent to the old process, and it enters the mode of terminating and finalizing its work, after which it is destroyed.

Example

class App {
  private isOnline = true

  public start() {
    console.log("Started")
    this.restartListener()
    this.loop()
  }

  private loop() {
    if (!this.isOnline) return
    console.log("Some business logic like redis/sql/amqp and others operation")
    this.loop()
  }

  private restartListener() {
     if (typeof process.send !== "function") return

     process.send(“ready”)
     process.on(“SIGINT”, () => {
       this.isOnline = false
       setTimeout(() => {
         process.exit()  
       }, 3000)
     })
  }

}