Workload Redources

Mundarija

1. Workload Resources Nima?
2. Pod Lifecycle
3. ReplicaSet
4. Deployment
5. StatefulSet
6. DaemonSet
7. Job
8. CronJob

---

Workload Resources Nima?

Umumiy Tushuncha

Workload - bu Kubernetes'da ishlaydigan ilova yoki service. Workload Resource'lar esa pod'larni yaratish va boshqarish uchun ishlatiladigan yuqori darajali abstraktsiyalardir.

Nima uchun Pod'ni bevosita ishlatmaymiz?

Pod'lar ephemeral (vaqtinchalik) va disposable. Ular:

• O'lib qolishi mumkin
• Node nosoz bo'lsa yo'qoladi
• Restart qilinganda yangi IP oladi
• Manual management qiyin

Workload Resource'lar muammoni hal qiladi:

• Avtomatik pod yaratish va o'chirish
• Self-healing
• Scaling
• Update va rollback strategiyalari
• Desired state management

Workload Resource Turlari

1. Deployment: Stateless ilovalar uchun
2. ReplicaSet: Pod'larni replicate qilish (odatda Deployment orqali)
3. StatefulSet: Stateful ilovalar uchun (database, queue)
4. DaemonSet: Har bir node'da bitta pod
5. Job: Bir martalik vazifalar
6. CronJob: Schedule bo'yicha vazifalar

---

Pod Lifecycle

Pod Fazalari

Pod hayot sikli davomida turli fazalardan o'tadi:

1. Pending

Ma'nosi: Pod yaratildi, lekin hali ishga tushmadi.

Sabablar:

• Scheduler hali node tanlayapti
• Container image download qilinayapti
• Volume'lar prepare qilinayapti
• Resource'lar yetishmayapti

Debug:

kubectl describe pod <pod-name>
# Events bo'limiga qarang

2. Running

Ma'nosi: Pod node'ga assign qilindi va kamida bitta konteyner ishlamoqda.

Holat:

• Barcha konteynerlar yaratildi
• Kamida bittasi running yoki starting/restarting

3. Succeeded

Ma'nosi: Barcha konteynerlar muvaffaqiyatli yakunlandi va qayta ishga tushmaydi.

Qachon: Job'lar uchun odatiy holat.

4. Failed

Ma'nosi: Barcha konteynerlar tugadi va kamida bittasi xato bilan to'xtadi.

Sabablar:

• Container crash bo'ldi
• OOMKilled (Out of Memory)
• Configuration xatosi
• Image pull error

5. Unknown

Ma'nosi: Pod holatini aniqlashning imkoni yo'q.

Sabab: Node bilan aloqa uzildi.

Container Holatlari

Har bir konteyner o'z holatiga ega:

1. Waiting

Konteyner ishga tushmagan:

• Image pull
• Volume mount
• Secrets load

2. Running

Konteyner ishlayapti. startupProbe, livenessProbe, readinessProbe tekshiriladi.

3. Terminated

Konteyner to'xtadi:

• Exit code 0: Normal tugash
• Exit code ≠ 0: Xato bilan tugash

Restart Policy

Pod spec'da restartPolicy belgilash mumkin:

1. Always (default):

spec:
  restartPolicy: Always

Har doim restart qilish. Stateless ilovalar uchun.

2. OnFailure:

spec:
  restartPolicy: OnFailure

Faqat fail bo'lganda restart. Job'lar uchun.

3. Never:

spec:
  restartPolicy: Never

Hech qachon restart qilmaslik. One-time task'lar uchun.

Pod Conditions

Pod condition'lar pod holatini batafsil tavsiflaydi:

1. PodScheduled: Pod node'ga assign qilindimi?
2. ContainersReady: Barcha konteynerlar ready holatidami?
3. Initialized: Barcha init konteynerlar muvaffaqiyatli tugadimi?
4. Ready: Pod trafikni qabul qilishga tayyormi?

Ko'rish:

kubectl describe pod <pod-name>
# Conditions bo'limiga qarang

Init Containers

Ta'rif: Init container'lar asosiy konteynerlar ishga tushishidan oldin ishlaydi.

Xususiyatlari:

• Ketma-ket ishga tushadi (sequential)
• Har biri muvaffaqiyatli tugashi kerak
• Asosiy konteynerlardan oldin

Foydalanish holatlari:

• Database migration
• Config file yaratish
• External service'ni kutish
• Dependency check

Misol:

apiVersion: v1
kind: Pod
metadata:
  name: myapp-pod
spec:
  initContainers:
  - name: init-myservice
    image: busybox
    command: ['sh', '-c', 'until nslookup myservice; do echo waiting for myservice; sleep 2; done;']
  - name: init-mydb
    image: busybox
    command: ['sh', '-c', 'until nslookup mydb; do echo waiting for mydb; sleep 2; done;']
  containers:
  - name: myapp-container
    image: busybox
    command: ['sh', '-c', 'echo The app is running! && sleep 3600']

Bu misolda:

1. Birinchi init container myservice DNS'ni kutadi
2. Ikkinchi init container mydb DNS'ni kutadi
3. Ikkisi ham tayyor bo'lgach, asosiy konteyner ishga tushadi

---

ReplicaSet

Ta'rif

ReplicaSet - bu ma'lum miqdordagi identik pod'larni ishlab turganini ta'minlaydigan controller.

Asosiy vazifa: Desired number of pods = Running pods

Qanday Ishlaydi?

ReplicaSet doimiy ravishda pod'larni kuzatadi:

Desired Replicas: 3
Current Replicas: 2
→ ReplicaSet 1 ta yangi pod yaratadi

Desired Replicas: 3
Current Replicas: 4
→ ReplicaSet 1 ta pod'ni o'chiradi

ReplicaSet YAML

Basic ReplicaSet:

apiVersion: apps/v1
kind: ReplicaSet
metadata:
  name: frontend
  labels:
    app: guestbook
    tier: frontend
spec:
  replicas: 3
  selector:
    matchLabels:
      tier: frontend
  template:
    metadata:
      labels:
        tier: frontend
    spec:
      containers:
      - name: php-redis
        image: gcr.io/google_samples/gb-frontend:v3

Muhim qismlar:

1. replicas: Nechta pod kerak
2. selector: Qaysi pod'larni boshqarish kerak
3. template: Pod template (yangi pod'lar uchun)

Selector

Selector pod'larni tanlash uchun ishlatiladi.

matchLabels (equality-based):

selector:
  matchLabels:
    app: nginx
    environment: production

matchExpressions (set-based):

selector:
  matchExpressions:
  - key: tier
    operator: In
    values:
    - frontend
    - backend
  - key: environment
    operator: NotIn
    values:
    - development

Operator'lar:

• In: Qiymat ro'yxatda bor
• NotIn: Qiymat ro'yxatda yo'q
• Exists: Key mavjud (value muhim emas)
• DoesNotExist: Key mavjud emas

Pod Template

Template - bu yangi pod'lar yaratish uchun blueprint.

Muhim:

• Template label'lari selector bilan mos kelishi kerak
• Template o'zgartirilsa, faqat yangi pod'larga ta'sir qiladi
• Mavjud pod'lar o'zgarmaydi

Scaling

Manual Scaling:

Kubectl orqali:

kubectl scale replicaset frontend --replicas=5

YAML edit:

kubectl edit replicaset frontend
# replicas: 3 → 5

YAML apply:

spec:
  replicas: 5

kubectl apply -f replicaset.yaml

ReplicaSet vs Deployment

Nega ReplicaSet'ni bevosita ishlatmaymiz?

ReplicaSet - low-level resource. Deployment - high-level abstraction.

Deployment qo'shimcha funktsiyalar:

• Rolling updates
• Rollback
• Update strategy
• Pause/Resume
• History

Tavsiya: Doimo Deployment ishlating, bevosita ReplicaSet emas!

---

Deployment

Ta'rif

Deployment - bu stateless ilovalarni deploy qilish va boshqarish uchun eng ko'p ishlatiladigan resource.

Deployment = ReplicaSet + Update Strategy + Rollback

Asosiy Imkoniyatlar

1. Deklarativ yangilanishlar: Desired state belgilang, Deployment qolganini hal qiladi
2. Rolling Updates: Zero-downtime yangilanish
3. Rollback: Oldingi versiyaga qaytish
4. Scaling: Pod'lar sonini o'zgartirish
5. Pause/Resume: Yangilanishni to'xtatish va davom ettirish
6. Status tracking: Deployment holatini kuzatish

Deployment YAML

Basic Deployment:

apiVersion: apps/v1
kind: Deployment
metadata:
  name: nginx-deployment
  labels:
    app: nginx
spec:
  replicas: 3
  selector:
    matchLabels:
      app: nginx
  template:
    metadata:
      labels:
        app: nginx
    spec:
      containers:
      - name: nginx
        image: nginx:1.19
        ports:
        - containerPort: 80

Advanced Deployment:

apiVersion: apps/v1
kind: Deployment
metadata:
  name: nginx-deployment
spec:
  replicas: 3
  strategy:
    type: RollingUpdate
    rollingUpdate:
      maxSurge: 1
      maxUnavailable: 1
  revisionHistoryLimit: 10
  selector:
    matchLabels:
      app: nginx
  template:
    metadata:
      labels:
        app: nginx
    spec:
      containers:
      - name: nginx
        image: nginx:1.19
        ports:
        - containerPort: 80
        resources:
          requests:
            memory: "64Mi"
            cpu: "250m"
          limits:
            memory: "128Mi"
            cpu: "500m"
        livenessProbe:
          httpGet:
            path: /
            port: 80
          initialDelaySeconds: 3
          periodSeconds: 3
        readinessProbe:
          httpGet:
            path: /
            port: 80
          initialDelaySeconds: 3
          periodSeconds: 3

Update Strategies

Deployment ikkita update strategiyasini qo'llab-quvvatlaydi:

1. RollingUpdate (Default)

Qanday ishlaydi: Eski pod'lar bosqichma-bosqich yangilar bilan almashtiriladi.

Parametrlar:

maxSurge:

• Desired replica count'dan qancha ortiq pod yaratish mumkin
• Raqam yoki foiz: 1 yoki 25%
• Default: 25%

maxUnavailable:

• Nechta pod unavailable bo'lishi mumkin
• Raqam yoki foiz: 1 yoki 25%
• Default: 25%

Misol:

strategy:
  type: RollingUpdate
  rollingUpdate:
    maxSurge: 1
    maxUnavailable: 0

Replicas: 3

1. Yangi pod yaratiladi (jami 4 ta pod)
2. Yangi pod Ready bo'lsa, eski pod o'chiriladi (jami 3 ta pod)
3. Yana yangi pod yaratiladi (jami 4 ta pod)
4. Jarayon davom etadi

Afzalliklar:

• Zero downtime
• Gradual rollout
• Quick rollback

Kamchiliklar:

• Sekinroq
• Qisqa vaqt davomida ikkita versiya parallel ishlaydi

2. Recreate

Qanday ishlaydi: Barcha eski pod'lar o'chiriladi, keyin yangilar yaratiladi.

strategy:
  type: Recreate

Afzalliklar:

• Oddiy
• Faqat bitta versiya ishlaydi

Kamchiliklar:

• Downtime
• Barcha pod'lar bir vaqtda restart

Qachon ishlatish:

• Database migration kerak
• Ikkita versiya parallel ishlay olmasa
• Development environment

Deployment Operatsiyalari

1. Yaratish

# YAML dan
kubectl apply -f deployment.yaml

# Imperativ
kubectl create deployment nginx --image=nginx:1.19 --replicas=3

2. Ko'rish

# Barcha deployment'lar
kubectl get deployments

# Batafsil
kubectl describe deployment nginx-deployment

# YAML ko'rish
kubectl get deployment nginx-deployment -o yaml

Output:

NAME               READY   UP-TO-DATE   AVAILABLE   AGE
nginx-deployment   3/3     3            3           5m

• READY: Tayyor pod'lar / Desired pod'lar
• UP-TO-DATE: Yangi pod template bilan pod'lar
• AVAILABLE: Foydalanuvchilarga ochiq pod'lar

3. Yangilash (Update)

Image yangilash:

kubectl set image deployment/nginx-deployment nginx=nginx:1.20

YAML orqali:

# YAML'ni o'zgartiring
kubectl apply -f deployment.yaml

Edit:

kubectl edit deployment nginx-deployment

Update jarayonini kuzatish:

kubectl rollout status deployment/nginx-deployment

Output:

Waiting for deployment "nginx-deployment" rollout to finish: 1 out of 3 new replicas have been updated...
Waiting for deployment "nginx-deployment" rollout to finish: 2 out of 3 new replicas have been updated...
deployment "nginx-deployment" successfully rolled out

4. Rollback

Rollout history:

kubectl rollout history deployment/nginx-deployment

Output:

REVISION  CHANGE-CAUSE
1         <none>
2         kubectl set image deployment/nginx-deployment nginx=nginx:1.20
3         kubectl set image deployment/nginx-deployment nginx=nginx:1.21

Oldingi versiyaga qaytish:

kubectl rollout undo deployment/nginx-deployment

Ma'lum revisiyaga qaytish:

kubectl rollout undo deployment/nginx-deployment --to-revision=2

Rollback jarayonini kuzatish:

kubectl rollout status deployment/nginx-deployment

5. Pause va Resume

Pause:

kubectl rollout pause deployment/nginx-deployment

Bu deployment yangilanishni to'xtatadi. Bir nechta o'zgarishlar qilishingiz mumkin:

kubectl set image deployment/nginx-deployment nginx=nginx:1.20
kubectl set resources deployment/nginx-deployment -c=nginx --limits=cpu=200m,memory=512Mi

Resume:

kubectl rollout resume deployment/nginx-deployment

Barcha o'zgarishlar bir vaqtda qo'llaniladi.

6. Scaling

# Manual
kubectl scale deployment nginx-deployment --replicas=5

# Autoscaling (keyingi mavzularda)
kubectl autoscale deployment nginx-deployment --min=3 --max=10 --cpu-percent=80

7. O'chirish

kubectl delete deployment nginx-deployment

Deployment Status

Deployment uchta holatga ega:

1. Progressing

Deployment quyidagi vazifalarni bajarayapti:

• Yangi ReplicaSet yaratish
• ReplicaSet scaling
• Yangi pod'larni Ready holatiga keltirish

Shartlar:

• type: Progressing
• status: "True"
• reason: NewReplicaSetAvailable

2. Complete

Deployment muvaffaqiyatli yakunlandi:

• Barcha replika'lar yangilandi
• Barcha replika'lar available
• Eski ReplicaSet'lar 0 ga scale qilindi

Shartlar:

• type: Progressing
• status: "True"
• reason: NewReplicaSetAvailable

3. Failed

Deployment bajarilmadi:

• Resource yetishmaydi (quota)
• Readiness probe fail
• Image pull xatosi
• Insufficient permissions

Shartlar:

• type: Progressing
• status: "False"
• reason: ProgressDeadlineExceeded

Deployment Best Practices

1. Resource Requests va Limits

Doim belgilang:

resources:
  requests:
    memory: "64Mi"
    cpu: "250m"
  limits:
    memory: "128Mi"
    cpu: "500m"

2. Health Checks

Liveness va Readiness probe'lar:

livenessProbe:
  httpGet:
    path: /healthz
    port: 8080
  initialDelaySeconds: 30
  periodSeconds: 10

readinessProbe:
  httpGet:
    path: /ready
    port: 8080
  initialDelaySeconds: 5
  periodSeconds: 5

3. Update Strategy

Zero-downtime uchun:

strategy:
  type: RollingUpdate
  rollingUpdate:
    maxSurge: 1
    maxUnavailable: 0

4. Labels

Yaxshi label'lar ishlating:

labels:
  app: myapp
  version: v1.0.0
  environment: production
  team: backend

5. Revision History

spec:
  revisionHistoryLimit: 10

---

StatefulSet

Ta'rif

StatefulSet - bu stateful ilovalar (database, queue, cache) uchun workload resource.

Stateful vs Stateless:

Stateless (Deployment)	Stateful (StatefulSet)
Pod'lar identik	Har bir pod unique
Istalgan tartibda yaratiladi	Ketma-ket yaratiladi
Random nomlar	Predictable nomlar
Ephemeral storage	Persistent storage

StatefulSet Xususiyatlari

1. Stable Network Identity

Har bir pod unique va stable hostname:

myapp-0.myapp.default.svc.cluster.local
myapp-1.myapp.default.svc.cluster.local
myapp-2.myapp.default.svc.cluster.local

Pattern: $(podname).$(service name).$(namespace).svc.cluster.local

2. Ordered Deployment va Scaling

Pod'lar ketma-ket yaratiladi:

myapp-0 → Ready
  ↓
myapp-1 → Ready
  ↓
myapp-2 → Ready

Scaling:

• Scale up: myapp-3, myapp-4, ...
• Scale down: myapp-4, myapp-3, ... (teskari tartibda)

3. Stable Storage

Har bir pod o'zining PersistentVolume'iga ega:

myapp-0 → pvc-myapp-0
myapp-1 → pvc-myapp-1
myapp-2 → pvc-myapp-2

Pod o'chirilsa ham, PVC saqlanadi va qayta yaratilganda qayta attach qilinadi.

StatefulSet YAML

Basic StatefulSet:

apiVersion: v1
kind: Service
metadata:
  name: nginx
  labels:
    app: nginx
spec:
  ports:
  - port: 80
    name: web
  clusterIP: None
  selector:
    app: nginx
---
apiVersion: apps/v1
kind: StatefulSet
metadata:
  name: web
spec:
  serviceName: "nginx"
  replicas: 3
  selector:
    matchLabels:
      app: nginx
  template:
    metadata:
      labels:
        app: nginx
    spec:
      containers:
      - name: nginx
        image: nginx:1.19
        ports:
        - containerPort: 80
          name: web
        volumeMounts:
        - name: www
          mountPath: /usr/share/nginx/html
  volumeClaimTemplates:
  - metadata:
      name: www
    spec:
      accessModes: [ "ReadWriteOnce" ]
      resources:
        requests:
          storage: 1Gi

Muhim qismlar:

1. serviceName: Headless service nomi
2. volumeClaimTemplates: Har bir pod uchun PVC template

Headless Service

StatefulSet headless service kerak:

apiVersion: v1
kind: Service
metadata:
  name: nginx
spec:
  clusterIP: None  # Headless
  selector:
    app: nginx
  ports:
  - port: 80

Nima uchun?

• Har bir pod individual DNS entry oladi
• Direct pod-to-pod communication

StatefulSet Operatsiyalari

1. Yaratish

kubectl apply -f statefulset.yaml

Pod'lar ketma-ket yaratiladi:

kubectl get pods -w

Output:

NAME    READY   STATUS              AGE
web-0   0/1     ContainerCreating   0s
web-0   1/1     Running             10s
web-1   0/1     ContainerCreating   0s
web-1   1/1     Running             10s
web-2   0/1     ContainerCreating   0s
web-2   1/1     Running             10s

2. Scaling

kubectl scale statefulset web --replicas=5

Yangi pod'lar ketma-ket yaratiladi:

web-3 → web-4

Scale down:

kubectl scale statefulset web --replicas=3

Pod'lar teskari tartibda o'chiriladi:

web-4 → web-3

3. Update

RollingUpdate (default):

spec:
  updateStrategy:
    type: RollingUpdate
    rollingUpdate:
      partition: 0

Pod'lar teskari tartibda yangilanadi:

web-2 → web-1 → web-0

Partition:

spec:
  updateStrategy:
    type: RollingUpdate
    rollingUpdate:
      partition: 2

Faqat web-2, web-3, ... yangilanadi. web-0 va web-1 eski versiyada qoladi.

OnDelete:

spec:
  updateStrategy:
    type: OnDelete

Pod'lar qo'lda o'chirilganda yangilanadi.

4. O'chirish

# StatefulSet o'chirish (pod'lar ham o'chiriladi)
kubectl delete statefulset web

# PVC'lar qoladi!
kubectl get pvc

PVC'larni o'chirish:

kubectl delete pvc www-web-0 www-web-1 www-web-2

StatefulSet Foydalanish Holatlari

1. Databases:

   • MySQL, PostgreSQL
   • MongoDB, Cassandra
   • Redis cluster

2. Message Queues:

   • RabbitMQ
   • Kafka
   • NATS

3. Distributed Systems:

   • Zookeeper
   • etcd
   • Consul

StatefulSet vs Deployment

StatefulSet	Deployment
Unique pod identity	Identical pods
Stable network ID	Random IP
Persistent storage	Ephemeral storage
Ordered operations	Parallel operations
Databases	Web servers

---

DaemonSet

Ta'rif

DaemonSet - bu har bir node'da bitta pod ishlab turishini ta'minlaydi.

Xususiyatlari:

• Yangi node qo'shilsa → avtomatik pod yaratiladi
• Node o'chirilsa → pod o'chiriladi
• Replica count yo'q (har bir node'da bittadan)

DaemonSet YAML

apiVersion: apps/v1
kind: DaemonSet
metadata:
  name: fluentd
  labels:
    app: fluentd
spec:
  selector:
    matchLabels:
      app: fluentd
  template:
    metadata:
      labels:
        app: fluentd
    spec:
      containers:
      - name: fluentd
        image: fluentd:v1.11
        resources:
          limits:
            memory: 200Mi
          requests:
            cpu: 100m
            memory: 200Mi
        volumeMounts:
        - name: varlog
          mountPath: /var/log
      volumes:
      - name: varlog
        hostPath:
          path: /var/log

Node Selector

Ma'lum node'larda ishlatish:

spec:
  template:
    spec:
      nodeSelector:
        disktype: ssd

Faqat disktype=ssd label'iga ega node'larda pod yaratiladi.

Foydalanish Holatlari

1. Monitoring:

   • Node exporter (Prometheus)
   • Datadog agent
   • New Relic agent

2. Logging:

   • Fluentd
   • Filebeat
   • Logstash

3. Networking:

   • CNI plugins
   • kube-proxy
   • Network policy agent

4. Security:

   • Security scanning
   • Compliance checking

5. Storage:

   • Storage daemon
   • Volume manager

---

Job

Ta'rif

Job - bu bir martalik vazifalarni bajarish uchun. Pod muvaffaqiyatli tugaguncha ishlaydi.

Job YAML

Simple Job:

apiVersion: batch/v1
kind: Job
metadata:
  name: pi
spec:
  template:
    spec:
      containers:
      - name: pi
        image: perl:5.34
        command: ["perl", "-Mbignum=bpi", "-wle", "print bpi(2000)"]
      restartPolicy: Never
  backoffLimit: 4

Parallel Job:

apiVersion: batch/v1
kind: Job
metadata:
  name: parallel-job
spec:
  completions: 10
  parallelism: 3
  template:
    spec:
      containers:
      - name: worker
        image: busybox
        command: ["sh", "-c", "echo Working... && sleep 10"]
      restartPolicy: Never

Job Parametrlari

1. completions

Nechta pod muvaffaqiyatli tugashi kerak:

spec:
  completions: 5

5 ta pod ketma-ket ishlab, muvaffaqiyatli tugashi kerak.

2. parallelism

Bir vaqtda nechta pod ishlashi mumkin:

spec:
  parallelism: 2

Maksimal 2 ta pod parallel ishlaydi.

Misol:

• completions: 10
• parallelism: 3

Pod1, Pod2, Pod3 → Running
Pod1 → Completed
Pod4 → Running
Pod2, Pod3 → Completed
Pod5, Pod6 → Running
...

3. backoffLimit

Pod fail bo'lsa, necha marta retry qilish:

spec:
  backoffLimit: 4

Default: 6

4. activeDeadlineSeconds

Job maksimal necha soniya ishlashi mumkin:

spec:
  activeDeadlineSeconds: 100

100 soniyadan keyin job to'xtatiladi (success yoki fail).

5. ttlSecondsAfterFinished

Job tugagandan keyin necha soniyadan so'ng o'chirilsin:

spec:
  ttlSecondsAfterFinished: 100

100 soniya o'tgach, job va pod'lar o'chiriladi.

Job Patterns

1. Single Job

Bitta pod, bir marta ishga tushadi:

spec:
  completions: 1
  parallelism: 1

2. Parallel Fixed Completion Count

Ko'p pod, umumiy soni ma'lum:

spec:
  completions: 10
  parallelism: 3

3. Work Queue

Ko'p pod, queue'dan vazifa oladi:

spec:
  parallelism: 3
  # completions yo'q

---

CronJob

Ta'rif

CronJob - bu schedule bo'yicha Job'larni ishga tushiradi.

CronJob YAML

apiVersion: batch/v1
kind: CronJob
metadata:
  name: hello
spec:
  schedule: "*/1 * * * *"
  jobTemplate:
    spec:
      template:
        spec:
          containers:
          - name: hello
            image: busybox
            command: ["sh", "-c", "date; echo Hello from Kubernetes CronJob"]
          restartPolicy: OnFailure

Cron Schedule Format

┌───────────── minute (0 - 59)
│ ┌───────────── hour (0 - 23)
│ │ ┌───────────── day of month (1 - 31)
│ │ │ ┌───────────── month (1 - 12)
│ │ │ │ ┌───────────── day of week (0 - 6) (Sunday to Saturday)
│ │ │ │ │
* * * * *

Misollar:

*/1 * * * *      → Har daqiqa
0 * * * *        → Har soat
0 0 * * *        → Har kun yarim tunda
0 0 * * 0        → Har hafta yakshanba yarim tunda
0 0 1 * *        → Har oyning 1-kuni
0 0 1 1 *        → Har yil 1-yanvar
*/5 * * * *      → Har 5 daqiqada
0 9-17 * * 1-5   → Dushanba-Juma, 9:00-17:00

CronJob Parametrlari

1. concurrencyPolicy

Agar oldingi job hali ishlab turibsayu yangi job vaqti kelsa:

Allow (default):

spec:
  concurrencyPolicy: Allow

Ikkalasi ham parallel ishlaydi.

Forbid:

spec:
  concurrencyPolicy: Forbid

Yangi job skip qilinadi.

Replace:

spec:
  concurrencyPolicy: Replace

Eski job to'xtatiladi, yangi job ishga tushadi.

2. successfulJobsHistoryLimit

Nechta muvaffaqiyatli job saqlansin:

spec:
  successfulJobsHistoryLimit: 3

Default: 3

3. failedJobsHistoryLimit

Nechta failed job saqlansin:

spec:
  failedJobsHistoryLimit: 1

Default: 1

4. startingDeadlineSeconds

Agar CronJob o'z vaqtida ishga tushmasa, maksimal qancha kechikish mumkin:

spec:
  startingDeadlineSeconds: 100

Agar 100 soniya kechiksa, job skip qilinadi.

Foydalanish Holatlari

1. Backup:

   • Database backup
   • File system backup
   • S3 sync

2. Data Processing:

   • ETL jobs
   • Report generation
   • Data aggregation

3. Cleanup:

   • Log rotation
   • Temporary file cleanup
   • Old data deletion

4. Monitoring:

   • Health checks
   • Metrics collection
   • Alert testing

---

Xulosa

Workload Resource'lar Kubernetes'ning asosiy tushunchalaridir:

✅ Pod: Eng kichik birlik, to'g'ridan-to'g'ri ishlatilmaydi ✅ ReplicaSet: Pod'larni replicate qilish (Deployment orqali) ✅ Deployment: Stateless ilovalar, rolling updates ✅ StatefulSet: Stateful ilovalar, stable identity ✅ DaemonSet: Har bir node'da bitta pod ✅ Job: Bir martalik vazifalar ✅ CronJob: Schedule bo'yicha vazifalar