[XPU] fix_same_req_id

[cmcamdy]

Motivation

💡 If this PR is a Cherry Pick, the PR title needs to follow the format by adding the [Cherry-Pick] label at the very beginning and appending the original PR ID at the end. For example, [Cherry-Pick][CI] Add check trigger and logic(#5191)

💡 如若此PR是Cherry Pick，PR标题需遵循格式，在最开始加上[Cherry-Pick]标签，以及最后面加上原PR ID，例如[Cherry-Pick][CI] Add check trigger and logic(#5191)

Modifications

Usage or Command

Accuracy Tests

Checklist

• Add at least a tag in the PR title.
  • Tag list: [[FDConfig],[APIServer],[Engine], [Scheduler], [PD Disaggregation], [Executor], [Graph Optimization], [Speculative Decoding], [RL], [Models], [Quantization], [Loader], [OP], [KVCache], [DataProcessor], [BugFix], [Docs], [CI], [Optimization], [Feature], [Benchmark], [Others], [XPU], [HPU], [GCU], [DCU], [Iluvatar], [Metax]]
  • You can add new tags based on the PR content, but the semantics must be clear.
• Format your code, run pre-commit before commit.
• Add unit tests. Please write the reason in this PR if no unit tests.
• Provide accuracy results.
• If the current PR is submitting to the release branch, make sure the PR has been submitted to the develop branch, then cherry-pick it to the release branch with the [Cherry-Pick] PR tag.

[codecov-commenter]

Codecov Report

❌ Patch coverage is 80.00000% with 1 line in your changes missing coverage. Please review.
⚠️ Please upload report for BASE (develop@fab344e). Learn more about missing BASE report.

Files with missing lines	Patch %	Lines
fastdeploy/engine/common_engine.py	50.00%	0 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             develop    #8040   +/-   ##
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  Coverage           ?   67.72%           
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  Hits               ?    44946           
  Misses             ?    18546           
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Flag	Coverage Δ
GPU	77.79% <80.00%> (?)
XPU	6.99% <0.00%> (?)

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[PaddlePaddle-bot]

🤖 Paddle-CI-Agent | pr_review | 2026-06-11 17:13:21

📋 Review 摘要

PR 概述：在 PD decode 预分配资源时新增重复 request_id 拒绝逻辑，并保留 D 侧返回的错误原因。
变更范围：fastdeploy/engine/common_engine.py、fastdeploy/engine/sched/resource_manager_v1.py
影响面 Tag：[Engine] [Scheduler] [PD Disaggregation]

问题

级别	文件	概述
🔴 Bug	fastdeploy/engine/sched/resource_manager_v1.py:1596	cache-task 模式下重复 request_id 被当作资源不足重试，P/D 会永久等待

📝 PR 规范检查

标题 Tag 使用 [XPU]，但本次 diff 修改的是 Engine/Scheduler 的 PD decode 资源预分配逻辑，未触及 XPU 专用 worker/model_runner/ops；PR 描述仍是模板占位内容，缺少具体 Motivation/Modifications/Usage/Accuracy Tests 内容。建议替换为以下完整内容。

标题建议（可直接复制）：

• [PD Disaggregation] Fix duplicate request id handling in decode preallocation

PR 描述建议（点击展开，可直接复制）

## Motivation
修复 P/D 分离场景下 Decode 侧收到重复 request_id 时可能复用或污染已有 KV cache 的问题。

## Modifications
- `fastdeploy/engine/sched/resource_manager_v1.py`: 在 Decode 侧资源预分配时检测 `request_id` 是否已存在于 `self.requests`，重复时设置错误信息并拒绝分配。
- `fastdeploy/engine/common_engine.py`: 在资源预分配失败回传给 Prefill 时保留 Decode 侧已经设置的错误原因，避免统一覆盖为 `Not enough resources`。

## Usage or Command
N/A

## Accuracy Tests
N/A

## Checklist

- [x] Add at least a tag in the PR title.
  - Tag list: [`[FDConfig]`,`[APIServer]`,`[Engine]`, `[Scheduler]`, `[PD Disaggregation]`, `[Executor]`, `[Graph Optimization]`, `[Speculative Decoding]`, `[RL]`, `[Models]`, `[Quantization]`, `[Loader]`, `[OP]`, `[KVCache]`, `[DataProcessor]`, `[BugFix]`, `[Docs]`, `[CI]`, `[Optimization]`, `[Feature]`, `[Benchmark]`, `[Others]`, `[XPU]`, `[HPU]`, `[GCU]`, `[DCU]`, `[Iluvatar]`, `[Metax]`]
  - You can add new tags based on the PR content, but the semantics must be clear.
- [ ] Format your code, run `pre-commit` before commit.
- [ ] Add unit tests. Please write the reason in this PR if no unit tests.
- [ ] Provide accuracy results.
- [x] If the current PR is submitting to the `release` branch, make sure the PR has been submitted to the `develop` branch, then cherry-pick it to the `release` branch with the `[Cherry-Pick]` PR tag.

总体评价

修复方向能避免 D 侧同一 request_id 复用已有 block，但当前永久失败和临时资源不足共用 False，会在 cache-task 模式下让重复请求卡住。需要先拆分失败语义，或在已有 error_msg 时回传错误并移除队列。

[PaddlePaddle-bot]

🤖 Paddle-CI-Agent | ci_status_monitor | 2026-06-13 15:17:33 UTC+08:00

CI报告基于以下代码生成（30分钟更新一次）:
PR commit: cb98744 | Merge base: fab344e (branch: develop)

---

1 Required任务 : 9/10 通过

总执行（rerun次数）	总任务	✅ 通过	❌ 失败	⏳ 运行中	⏸️ 等待中	跳过
41(0)	41	37	4	0	0	0

任务	错误类型	置信度	日志
Run FastDeploy Unit Tests and Coverage / run_tests_with_coverage	PR问题	高	Job

2 失败详情

🔴 Run FastDeploy Unit Tests and Coverage / run_tests_with_coverage — PR问题（置信度: 高）

错误类型: PR问题 | 置信度: 高
分析器: 通用分析(fallback)
失败用例: 差异覆盖率校验

用例	错误摘要
diff-cover	fastdeploy/engine/common_engine.py 新增行未覆盖，diff coverage 66%，低于 80% 阈值

关键日志:

Failure. Coverage is below 80%.
Diff Coverage
fastdeploy/engine/common_engine.py (0.0%): Missing lines 2137-2138
fastdeploy/engine/sched/resource_manager_v1.py (100%)
TEST_EXIT_CODE: 0
COVERAGE_EXIT_CODE: 9
"total_num_violations": 2, "total_percent_covered": 66

• 根因摘要: common_engine新增分支缺少测试覆盖
  PR 在 fastdeploy/engine/common_engine.py 将资源预分配失败时的错误写入改成 if not task.get("error_msg", None) 后再设置默认 "Not enough resources"。CI 单测本身通过，但新增 guard/fallback 分支没有被测试覆盖，导致 diff-cover --fail-under=80 返回 9。

修复建议:

1. 在 tests/engine/test_common_engine.py 为 decode splitwise 资源预分配失败路径补充用例，覆盖 fastdeploy/engine/common_engine.py:2128-2129：构造 preallocate_resource_in_d() 返回 False 且 task 已带 error_msg="Duplicate request id in decode" 的场景，断言发送给 prefill 的 task 保留原错误而不是被 "Not enough resources" 覆盖；同时可覆盖无 error_msg 时写入默认错误的分支。

关联变更: fastdeploy/engine/common_engine.py:2128-2129, fastdeploy/engine/sched/resource_manager_v1.py:1590-1596