[Feat] Adding QoE-based Scheduler for Disaggregated Prefill

[YuhanLiu11]

QoE-based Scheduler

Overview

This PR introduces a new disaggregated QoE routing algorithm that separates the prefill and decoding phases of LLM inference, allowing for dedicated optimized endpoints for each phase. This architectural change enables better resource utilization and improved performance by routing requests to specialized endpoints based on their phase.

Key Changes

• Added new DisaggregatedQoERouter implementation
• Updated router initialization and reconfiguration logic
• Added request lifecycle tracking for prefill and decoding phases
• Implemented endpoint tagging system for phase-specific routing
• Added phase-specific metrics collection

Implementation Details

• Router identifies prefill vs decoding requests based on message history
• Endpoints are tagged with "prefill" or "decoding" identifiers
• Request tracking maintains state between prefill and decoding phases
• Metrics collection extended to track phase-specific performance

BEFORE SUBMITTING, PLEASE READ THE CHECKLIST BELOW AND FILL IN THE DESCRIPTION ABOVE

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Detailed Checklist (Click to Expand)

Thank you for your contribution to production-stack! Before submitting the pull request, please ensure the PR meets the following criteria. This helps us maintain the code quality and improve the efficiency of the review process.

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Please try to classify PRs for easy understanding of the type of changes. The PR title is prefixed appropriately to indicate the type of change. Please use one of the following:

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