DSPex Pooling Configuration

DSPex supports two modes of operation for the Python bridge:

1. Single Bridge Mode - One Python process handles all requests
2. Pool Mode - Multiple Python processes with session isolation

Configuration

The mode is determined by the :pooling_enabled configuration:

# config/config.exs or config/runtime.exs
config :dspex,
  pooling_enabled: false  # or true for pool mode

Single Bridge Mode (Default)

When pooling_enabled: false, DSPex uses a single Python process:

• Adapter: DSPex.Adapters.PythonPort
• Use Case: Development, testing, low-traffic deployments
• Benefits: Simple, low resource usage
• Limitations: No concurrent request handling, shared state

Pool Mode

When pooling_enabled: true, DSPex uses a pool of Python processes:

• Adapter: DSPex.Adapters.PythonPool
• Use Case: Production, high-traffic deployments
• Benefits: Concurrent requests, session isolation, fault tolerance
• Configuration:

  config :dspex,
    pooling_enabled: true,
    pool_size: System.schedulers_online() * 2,
    pool_overflow: 2
  

Testing Both Modes

The test suite covers both modes to ensure compatibility:

# Test with single bridge mode (default)
TEST_MODE=full_integration mix test

# Test with pool mode (when fixed)
TEST_MODE=full_integration POOLING_ENABLED=true mix test

Adapter Selection

The system automatically selects the appropriate adapter based on configuration:

# This returns PythonPort or PythonPool based on pooling_enabled
adapter = DSPex.Adapters.Registry.get_adapter()

Both adapters implement the same behavior, so code using them doesn’t need to change.

Current Status

• Single Bridge Mode: ✅ Fully functional
• Pool Mode: ⚠️ Worker initialization bug being fixed

The system defaults to single bridge mode until the pool worker initialization issue is resolved.