Dispatch Guide

Slither.Dispatch executes Python work in bounded concurrent batches.

API

• run/2: process full input and return list.
• stream/2: lazy result stream.
• call_batch/2: execute one pre-assembled batch.

See lib/slither/dispatch.ex.

Backpressure

Slither.Dispatch.Runner uses Task.async_stream with max_concurrency. That caps in-flight batches and prevents unbounded queue growth.

Strategies

• FixedBatch: fixed-size chunks.
• WeightedBatch: cumulative weight threshold (max_weight, weight_fn).
• KeyPartition: group items by key.

See lib/slither/dispatch/strategies/*.ex.

Executors

• Slither.Dispatch.Executors.SnakeBridge: calls Python module/function via SnakeBridge.call.
• Slither.Dispatch.Executors.Snakepit: calls adapter commands via Snakepit.execute.

Error Policies

• :halt
• :skip
• {:route, fun}
• {:retry, opts} (currently halts at dispatch level)

Example

See lib/slither/examples/batch_stats/stats_demo.ex for all strategies.