Serverless Cost Modelling, Quotas आणि Service Limits सोप्या भाषेत

By Ravindra Bagale, trainer · LinkedIn · Last updated: 2 November 2026

1. रोजचे: Rohan bill

Rohan (INR) webhook. Partner retry loop + fat logs = Monday bill.

Logs/metrics: CloudWatch; compute: Lambda; bills: Cost Explorer.

2. का model?

हे का लागतं?

Pay-per-use = चांगले design. Quotas = soft walls. Model = honest traffic.

हे काय आहे?

Cost = units x price. Quotas = limits. Reserved concurrency = critical protect.

3. Vertical diagram

4. How: model

कसं करायचं (step by step)

5. Commands

Lambda account

aws lambda get-account-settings --region ap-south-1

अर्थ: Unreserved concurrency पाहा.

Quotas

aws service-quotas list-service-quotas --region ap-south-1 \
  --service-code lambda --query 'Quotas[?contains(QuotaName, `Concurrent`)].{N:QuotaName,V:Value}' --output table

अर्थ: Black Friday आधी concurrent quota.

CE get-cost

aws ce get-cost-and-usage --time-period Start=2026-10-01,End=2026-11-01 \
  --granularity MONTHLY --metrics UnblendedCost \
  --group-by Type=DIMENSION,Key=SERVICE --query 'ResultsByTime[0].Groups[:5]' 

अर्थ: CE एकदा enable — मग CLI.

Log retention

aws logs describe-log-groups --region ap-south-1 \
  --query 'logGroups[?retentionInDays==`null`].logGroupName' --output text | head

अर्थ: null retention = forever bill.

6. Runaways

• Self-trigger loop.
• Visibility storm.
• No backoff.
• Fat DEBUG.
• Idle provisioned.

7. Industries

• Fintech budget.
• Ecommerce 10x.
• Media GB-s.
• SaaS tags.
• IoT storms.

8. Lab

9. Lab - model

Org block नसेल तर ap-south-1 (Mumbai). आधी budget alert.

कसं करायचं (step by step)

1. 1x/10x estimate.
2. Account settings.
3. Null retention.
4. Budget alert.

Cleanup (billing थांबवा)

1. Cleanup budget.
2. No silent prod.

10. एकाच pattern — वेगवेगळ्या industries

• Fintech (Aisha, Lagos): payment webhooks → SQS → Lambda.
• Ecommerce (Rohan, Pune): checkout API; inventory SNS fan-out.
• Healthcare (Mei, Singapore): SNS SMS; PHI + fine-grained IAM.
• EdTech (Diego, São Paulo): EventBridge nightly cleanup.
• Logistics (Fatima, Casablanca): EventBridge + saga.
• Media (Kenji, Osaka): S3 → Lambda thumbs + fan-out.
• SaaS (Priya, Bengaluru): Cognito + per-tenant partition.
• Gov (Omar, Amman): strangler fig per form route.

11. Troubleshooting checklist

1. Region confirm करा.
2. CloudWatch Logs + request id.
3. Execution role permissions.
4. DLQ + oldest message age.
5. curl -v + CORS.
6. SFN event history.
7. Linked chapter पुन्हा वाचा.
8. Cost: concurrency/retries.

12. सामान्य errors आणि fixes

प्रत्येक row = खरी चूक. Panic करण्याआधी fix वाचा.

13. FAQ

14. Interview Q&A (Beginner / Mid / Senior + MNC)

15. Tips — English, मराठी आणि हिंदी

16. Architecture decision checklist

1. User journey 5 bullets, no AWS names.
2. Sync vs async mark.
3. Failure mode.
4. Idempotency key.
5. Data from access patterns.
6. Cost 1x and 10x.
7. Quotas ap-south-1.
8. Auth decision.
9. On-call + alarm.
10. Deep chapter link.
11. मग console/IaC.

17. Copy-paste quick commands

# Region and identity
aws configure get region
aws sts get-caller-identity

# Lambda landscape
aws lambda list-functions --region ap-south-1 --max-items 20 \
  --query 'Functions[].{N:FunctionName,R:Runtime,T:Timeout,M:MemorySize}' --output table
aws lambda get-account-settings --region ap-south-1

# API Gateway (HTTP APIs)
aws apigatewayv2 get-apis --region ap-south-1 --query 'Items[].{N:Name,Id:ApiId,Ep:ProtocolType}' --output table

# Queues and topics
aws sqs list-queues --region ap-south-1
aws sns list-topics --region ap-south-1 --query 'Topics[].TopicArn'

# Event buses and state machines
aws events list-event-buses --region ap-south-1
aws stepfunctions list-state-machines --region ap-south-1 --query 'stateMachines[].name'

# DynamoDB tables (names only)
aws dynamodb list-tables --region ap-south-1

Sandbox + read-only IAM.

18. अजून industry आणि stack stories

• Fintech Lagos: webhook → SQS → idempotent ledger.
• Ecommerce Pune: throttle + fan-out.
• Healthcare SG: SNS + PHI IAM.
• EdTech: EventBridge cleanup.
• Logistics: bus + saga.
• Media: avoid recursive S3.
• SaaS: tenant partition.
• Gov: strangler peel.
• Startup: Function URL → HTTP API.
• Retail: FIFO vs Standard.

• Python: thin handlers.
• Node: async/await.
• Java: SnapStart.
• .NET: package size.
• Go: static binary.
• PHP: hybrid.

19. Glossary

20. Practice: मोठ्याने explain

1. 60s: serverless cost quotas गोष्ट.
2. 60s: sync vs async checkout.
3. 60s: Lambda नको कधी.
4. 60s: DLQ + idempotency.
5. Record ×2.

21. Safe lab hygiene

• Tag owner+expiry.
• Budget alarm आधी.
• Read-only first.
• Cleanup.
• No secrets in env/screenshots.
• No provisioned on hello.

22. या chapter च्या links

• Compute: Lambda.
• HTTP: API Gateway.
• Data: DynamoDB.
• Messaging: SQS/SNS.
• Events: EventBridge.
• Workflows: Step Functions.
• build-* projects link.

23. Myths

24. Serverless error budget

Checkout error budget 0.1% असेल तर aggressive retries email duplicates देऊन budget जाळू शकतात. Money SLO ≠ notify SLO.

1. दोन SLOs.
2. Money retries bounded.
3. Notify best-effort.
4. Money page; notify ticket.

25. Regional notes (ap-south-1)

• Labs Mumbai.
• Feature availability.
• Data residency.
• Latency India.

26. Naming conventions

# Suggested prefixes
# Lambda:  pay-intake-prod, pay-worker-prod
# SQS:     pay-orders.fifo / pay-orders-dlq
# SNS:     pay-order-events
# EB bus:  pay.domain
# SFN:     pay-refund-saga
# DDB:     pay-orders-prod

env + domain नावात ठेवा. CloudWatch grep सोपा.

27. Pre-mortems

1. Double charge headline.
2. DLQ drain plan.
3. Cognito outage mode.
4. Runbook.

28. Currency / locale

Currencies आणि names rotate करा — global mental model.

29. Festival 10x

1. Model 10x.
2. Quota low.
3. Reserve pay.
4. Alarm 80.

30. Anti-patterns

• No cost owner.
• DEBUG prod.
• Quota day-of.

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