Cache Service

The Cache Service provides distributed caching for simulation results with session-based access control.

Overview

Features:

• Distributed Caching - Share results across team members

• Session Authentication - Role-based access control

• TTL Support - Automatic cache expiration

• Invalidation - Pattern-based cache clearing

• Statistics - Hit rates and usage metrics

• Dual Backend - SQLite (dev) or PostgreSQL (prod)

Quick Start

Starting the Service

# SQLite backend (development)
python -m sim2l.services.cache_service --backend sqlite --port 8001

# PostgreSQL backend (production)
python -m sim2l.services.cache_service \
    --backend postgresql \
    --db-url "postgresql://user:pass@localhost/sim2l_cache" \
    --port 8001

Using the Client

from sim2l.database import CacheClient, get_session_manager

# Create session
session = get_session_manager().create_anonymous_session()

# Connect to service
cache = CacheClient(
    "http://localhost:8001",
    session_id=session.session_id
)

# Store in cache
cache.set(
    cache_key="thermal_sim/350K",
    simulation_id=42,
    simulation_name="thermal_sim",
    simulation_version="1.0.0",
    execution_id="exec-001",
    squid_id="thermal_sim/1.0.0/xyz",
    input_hash="hash123",
    run_db_path="/path/to/run.db",
    ttl_hours=24
)

# Retrieve from cache
result = cache.get("thermal_sim/350K")
if result:
    print("Cache hit!")
else:
    print("Cache miss")

REST API

GET /cache/{cache_key}

Retrieve a cached result.

Headers: - X-Session-ID: Session ID for authentication

Response:

{
  "cache_key": "thermal_sim/350K",
  "simulation_id": 42,
  "simulation_name": "thermal_sim",
  "simulation_version": "1.0.0",
  "execution_id": "exec-001",
  "squid_id": "thermal_sim/1.0.0/xyz",
  "input_hash": "hash123",
  "run_db_path": "/path/to/run.db",
  "created_at": "2024-01-01T12:00:00",
  "expires_at": "2024-01-02T12:00:00",
  "hit_count": 5
}

POST /cache

Store a cache entry.

Request:

{
  "cache_key": "thermal_sim/350K",
  "simulation_id": 42,
  "simulation_name": "thermal_sim",
  "simulation_version": "1.0.0",
  "execution_id": "exec-001",
  "squid_id": "thermal_sim/1.0.0/xyz",
  "input_hash": "hash123",
  "run_db_path": "/path/to/run.db",
  "ttl_hours": 24,
  "metadata": {}
}

Response:

{
  "success": true,
  "cache_key": "thermal_sim/350K"
}

POST /cache/invalidate

Invalidate cache entries.

Request:

{
  "simulation_id": 42,
  "pattern": "thermal_sim/*",
  "reason": "new version released"
}

Response:

{
  "success": true,
  "invalidated_count": 15
}

GET /cache/stats

Get cache statistics.

Query Parameters: - simulation_id: Filter by simulation (optional)

Response:

{
  "total_entries": 1000,
  "total_hits": 5000,
  "total_misses": 500,
  "hit_rate": 0.909,
  "total_size_bytes": 104857600,
  "invalidation_count": 10
}

GET /health

Health check.

Response:

{
  "status": "healthy",
  "service": "cache",
  "backend": "postgresql"
}

Configuration

Command Line

python -m sim2l.services.cache_service \
    --backend {sqlite|postgresql} \
    --db-path /path/to/cache.db \
    --db-url postgresql://user:pass@host/db \
    --port 8001 \
    --host 0.0.0.0 \
    --no-auth

Environment Variables

export SIM2L_CACHE_BACKEND=postgresql
export SIM2L_CACHE_DB_URL=postgresql://user:pass@localhost/sim2l_cache
export SIM2L_CACHE_PORT=8001

Docker

services:
  cache-service:
    build:
      context: .
      dockerfile: docker/Dockerfile.cache
    ports:
      - "8001:8001"
    environment:
      - CACHE_BACKEND=postgresql
      - CACHE_DB_URL=postgresql://user:pass@postgres/sim2l_cache

API Reference