Module 3: How Kafka Solves the Problem

# Kafka Message Flow Example

## Step 1: Producer Sends Message
Producer Configuration:
- Topic: "user-events"
- Message: {"user_id": 123, "action": "login", "timestamp": "2024-01-15T10:30:00Z"}
- Partition: 0 (or auto-assigned)

## Step 2: Broker Processing
Broker Actions:
1. Receives message from producer
2. Writes to partition 0 of "user-events" topic
3. Replicates to other brokers (if replication > 1)
4. Sends acknowledgment to producer
5. Updates partition metadata

## Step 3: Consumer Processing
Consumer Actions:
1. Subscribes to "user-events" topic
2. Reads from partition 0
3. Processes message
4. Commits offset
5. Continues to next message

## Step 4: Offset Management
Offset Tracking:
- Consumer tracks position in partition
- Can restart from last committed offset
- Enables fault tolerance and replay

## Complete Flow:
Producer → Topic (Partition 0) → Broker → Consumer
   ↓              ↓                ↓         ↓
Message      Persistence      Replication  Processing
   ↓              ↓                ↓         ↓
Ack ←─────────── Disk ←─────────── Replicas  Offset Commit