Atlas Triggers va Functions — serverless logika

~20 daq · MongoDB · Atlas va Deployment

Muammodan boshlaylik

Vazifalar:

• Yangi buyurtma tushganda — omborchiga Telegram xabar
• Mahsulot narxi o'zgarganda — narxTarixi collection iga yozish
• Har kecha soat 3 da — 30 kundan eski savatlarni tozalash
• Admin paneldan, skriptdan yoki boshqa xizmatdan qilingan o'zgarishlar ham hisobga olinsin

Express middleware da yozsangiz — faqat shu ilova orqali qilingan o'zgarishlar ushlanadi. Cron uchun esa alohida server yoki jarayon kerak.

Triggers nima?

Atlas Triggers — ma'lum hodisa yuz berganda Atlas ning o'zida bajariladigan serverless funksiyalar:

Funksiyalar JavaScript da yoziladi va Atlas serverlarida ishlaydi — sizga server kerak emas.

Hayotiy o'xshatma

Uyda "aqlli" tizim: eshik ochilganda — chiroq yonadi (database trigger), har kuni soat 7 da — choynak qaynaydi (scheduled trigger). Siz har safar o'zingiz chiroqni yoqishingiz shart emas va kim eshikni ochganidan qat'i nazar — chiroq yonadi.

Change Streams — asos

Database trigger lar MongoDB ning Change Streams imkoniyatiga asoslangan — collection dagi o'zgarishlar oqimiga obuna bo'lish. Uni o'z ilovangizda ham to'g'ridan-to'g'ri ishlatish mumkin:

const oqim = Buyurtma.watch([{ $match: { operationType: 'insert' } }])

oqim.on('change', (ozgarish) => {
  console.log('Yangi buyurtma:', ozgarish.fullDocument._id)
})

Change Streams replica set talab qiladi. Atlas Triggers — buning boshqariladigan versiyasi: qayta ulanish, "qayerda to'xtagan edim" (resume token) va xatolar — Atlas tomonidan.

Database trigger yaratish

Atlas → Triggers → Add Trigger:

• Trigger Type: Database
• Cluster, Database: dokon, Collection: buyurtmalar
• Operation Type: Insert
• Full Document: ✅ (yangi documentni funksiyaga berish)
• Event Type: Function

exports = async function (changeEvent) {
  const buyurtma = changeEvent.fullDocument

  const token = context.values.get('telegramToken')
  const chatId = context.values.get('omborChatId')

  await context.http.post({
    url: `https://api.telegram.org/bot${token}/sendMessage`,
    body: {
      chat_id: chatId,
      text: `🛒 Yangi buyurtma #${buyurtma.raqam}\nSumma: ${buyurtma.summa.toLocaleString()} so'm`,
    },
    encodeBodyAsJSON: true,
  })
}

• changeEvent.fullDocument — yangi document
• context.values / context.secrets — maxfiy qiymatlar (token kodga yozilmaydi)
• context.http — tashqi so'rovlar

Narx tarixi — update trigger

Operation Type: Update, Match Expression bilan faqat narx o'zgarishlari:

{ "updateDescription.updatedFields.narx": { "$exists": true } }

exports = async function (changeEvent) {
  const db = context.services.get('mongodb-atlas').db('dokon')
  const { _id } = changeEvent.documentKey
  const yangiNarx = changeEvent.updateDescription.updatedFields.narx

  await db.collection('narxTarixi').insertOne({
    mahsulot: _id,
    narx: yangiNarx,
    sana: new Date(),
  })
}

context.services.get('mongodb-atlas') — funksiya ichidan bazaga murojaat.

[!WARNING] Trigger o'zi kuzatayotgan collection ga yozsa — cheksiz sikl: o'zgarish → trigger → o'zgarish → trigger... Match Expression bilan o'z o'zgarishlaringizni filtrlang yoki boshqa collection ga yozing.

Scheduled trigger

Trigger Type: Scheduled, Schedule: 0 3 * * * (har kuni soat 03:00 UTC — Toshkent bilan 5 soat farqni hisobga oling).

exports = async function () {
  const db = context.services.get('mongodb-atlas').db('dokon')
  const chegara = new Date(Date.now() - 30 * 24 * 60 * 60 * 1000)

  const natija = await db.collection('savatlar').deleteMany({ yangilangan: { $lt: chegara } })
  console.log(`O'chirildi: ${natija.deletedCount}`)
}

Hisobotlarni oldindan hisoblash ($merge, 18-dars), eskirgan ma'lumotlarni arxivlash uchun ham qulay.

[!TIP] Oddiy "N kundan keyin o'chirish" uchun trigger shart emas — TTL index (27-dars) buni MongoDB ning o'zida bepul va oddiyroq bajaradi.

Funksiyalar va loglar

• App Services → Functions — funksiyalarni yozish, sinash (Run), boshqa funksiyalardan chaqirish: context.functions.execute('nom', arg)
• Logs — har bir ishga tushish, console.log natijalari va xatolar
• Funksiya vaqt va xotira chegaralariga ega — og'ir ishlar uchun emas

Trigger yoki ilova kodi

[!INFO] Trigger kodini versiyalash uchun App Services ni GitHub bilan bog'lash yoki atlas/appservices CLI orqali deploy qilish mumkin. Shunda trigger lar ham kod sifatida ko'rib chiqiladi.

Tez-tez uchraydigan xatolar

Maxfiy kalitlarni funksiya kodiga yozish

context.values va Secrets dan foydalaning.

Vaqt mintaqasini unutish

Cron — UTC da. "Soat 3 da" (Toshkent) — 0 22 * * * (UTC).

Trigger ni to'xtatib, unutish

Xato ko'p bo'lsa Atlas trigger ni to'xtatishi mumkin (suspended). Loglar va ogohlantirishlarni kuzatib boring; qayta yoqishda resume token dan davom ettirish mumkin.

Xulosa

• Atlas Triggers — hodisalarga javoban serverless funksiyalar: Database, Scheduled, Authentication
• Database trigger — Change Streams asosida; changeEvent.fullDocument, updateDescription
• Match Expression — faqat kerakli o'zgarishlar; o'z collection iga yozib cheksiz sikl yaratmang
• Scheduled — cron (UTC)
• context.values/secrets, context.http, context.services
• Oddiy muddatli o'chirish — TTL index; asosiy biznes mantiq — ilovada

Keyingi dars: 55-dars — Monitoring — Atlas Performance Advisor, slow queries