Distributed Tracing System - System Architecture

High-Level Architecture

Distributed Tracing — Collection & Processing Pipeline

Core Components

Trace Collector

Responsibilities:
- Receive spans from agents
- Validate span data
- Apply sampling decisions
- Buffer and batch spans
- Forward to processing

Span Processor

Processing Pipeline:
1. Validation
2. Enrichment (add metadata)
3. Sampling decision
4. Aggregation
5. Storage write

Storage Layer

Options:
- Cassandra: High write throughput
- Elasticsearch: Rich query capabilities
- ClickHouse: Fast analytics

Chosen: Cassandra + Elasticsearch
- Cassandra for raw spans
- Elasticsearch for queries

This architecture provides scalable, low-latency distributed tracing.