Sequencer (Hash-Based Routing)

[prosdev]

Phase: 4 - Processing Pipeline
Estimated Effort: 2 hours
Tasks: Task 7 from specs/core-pipeline/tasks.md

Checklist

Task 7: Implement Sequencer (2 hours)

• Create Sequencer class
• Implement get_partition_id() with FNV-1a hash
• Implement _get_routing_key() (userId or anonymousId)
• Handle missing identifiers (fallback)
• Configurable num_partitions (default: 16)
• Write unit tests (verify consistent routing)

Acceptance Criteria

• Same userId always routes to same partition
• FNV-1a hash algorithm used
• Partition distribution is even
• Handles events without identifiers
• Unit tests pass

Files to Create

src/eventkit/processing/sequencer.py
tests/unit/processing/test_sequencer.py

Dependencies: Issue #1
User Stories: Story 4 (Consistent Ordering per Identity)