[BugFix] Seperate prometheus multiproc dir for single-server multi-dp services

[liyonghua0910]

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 35.13514% with 24 lines in your changes missing coverage. Please review.
⚠️ Please upload report for BASE (develop@cbb0811). Learn more about missing BASE report.

Files with missing lines	Patch %	Lines
...astdeploy/metrics/prometheus_multiprocess_setup.py	47.82%	12 Missing ⚠️
fastdeploy/engine/common_engine.py	16.66%	5 Missing ⚠️
fastdeploy/engine/engine.py	16.66%	5 Missing ⚠️
fastdeploy/entrypoints/openai/multi_api_server.py	0.00%	2 Missing ⚠️

Additional details and impacted files

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[PaddlePaddle-bot]

🤖 Paddle-CI-Agent | ci_status_monitor | 2026-06-18 18:44:05

CI报告基于以下代码生成（30分钟更新一次）:
PR commit: 9a08ce4 | Merge base: cbb0811 (branch: develop)

---

1 Required任务 : 7/10 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	34	4	2	1	0

任务	错误类型	置信度	日志
Pre Commit	PR问题：isort import 排序不合规	高	Job
Approval	需要 Approval	高	Job

2 失败详情

🔴 Pre Commit — PR问题（置信度: 高）

分析器: 通用分析(fallback)

失败用例:

用例	错误摘要
isort	fastdeploy/engine/common_engine.py、fastdeploy/engine/engine.py import 顺序/格式不符合 isort，hook 自动修改文件后失败

关键日志:

isort....................................................................Failed
- hook id: isort
- files were modified by this hook
Fixing /home/paddle-8/actions-runner/_work/FastDeploy/FastDeploy/fastdeploy/engine/common_engine.py
Fixing /home/paddle-8/actions-runner/_work/FastDeploy/FastDeploy/fastdeploy/engine/engine.py
pre-commit run --files fastdeploy/engine/common_engine.py fastdeploy/engine/engine.py fastdeploy/entrypoints/openai/multi_api_server.py fastdeploy/metrics/prometheus_multiprocess_setup.py

• 根因摘要: 新增 import 未按 isort 排序

PR 在两个 engine 文件中新增 from fastdeploy.metrics.prometheus_multiprocess_setup import setup_dp_prometheus_dir, get_original_prom_dir，顺序和换行不符合 isort 规则。isort --check-only --diff 显示应拆成括号多行导入，并将 get_original_prom_dir 排在 setup_dp_prometheus_dir 前，因此这是 PR 变更直接导致的代码风格失败。

修复建议:

1. 在 fastdeploy/engine/common_engine.py:68 和 fastdeploy/engine/engine.py:53 中把该导入改为 isort 输出的多行格式：先 get_original_prom_dir，再 setup_dp_prometheus_dir。
2. 本地运行 pre-commit run --files fastdeploy/engine/common_engine.py fastdeploy/engine/engine.py fastdeploy/entrypoints/openai/multi_api_server.py fastdeploy/metrics/prometheus_multiprocess_setup.py 确认。

关联变更: fastdeploy/engine/common_engine.py:68、fastdeploy/engine/engine.py:53

🔴 Approval — 需要 Approval（置信度: 高）

该 Job 需要人工 Approval，完成审批后 CI 才会继续执行。

• 根因摘要: Workflow 等待人工审批

修复建议:

1. 请通过人工审批。

关联变更: 无，属于审批流程状态。

[PaddlePaddle-bot]

🤖 Paddle-CI-Agent | pr_review | 2026-06-18 17:35:56

📋 Review 摘要

PR 概述：为单 API server 多 DP 服务按 DP rank 切分 Prometheus multiprocess 目录。
变更范围：Engine/EngineService DP 子服务启动、multi_api_server 子进程环境、Prometheus multiprocess setup。
影响面 Tag：[Engine] [APIServer]

问题

本轮未发现新的非历史阻塞性问题；历史 finding 状态见下表，PR 规范问题在下面章节报。

历史 Findings 修复情况

Finding	问题	状态
F1	父进程环境切到 dp0 后，公开 /metrics 仍只采集当前目录。	⚠️ 仍存在
F2	EngineService/AsyncLLM 启动路径也切回 dp0，但 metrics HTTP 入口未聚合多个 DP 子目录。	⚠️ 仍存在
F3	每次 /metrics scrape 把完整 metrics 文本写入 INFO 日志。	✅ 已修复

📝 PR 规范检查

PR 标题 tag 符合规范，但描述各章节仍是模板占位内容，建议替换为下面可复制版本。

标题建议（可直接复制）：

• [BugFix] Separate prometheus multiproc dir for single-server multi-dp services

PR 描述建议（点击展开，可直接复制）

## Motivation
修复单 API server 多 DP 部署中 Prometheus multiprocess 目录共享导致 Counter/Histogram 指标容易混淆的问题。

## Modifications
- `fastdeploy/metrics/prometheus_multiprocess_setup.py`: 新增 `setup_dp_prometheus_dir`，按 DP id 创建独立的 Prometheus multiprocess 目录。
- `fastdeploy/engine/engine.py`、`fastdeploy/engine/common_engine.py`: 启动 DP 子服务前切换到对应 DP 的 `PROMETHEUS_MULTIPROC_DIR`，子服务启动后切回 DP0 目录。

## Usage or Command
N/A

## Accuracy Tests
N/A（仅调整 metrics multiprocess 目录，不影响模型精度）

## 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.
- [ ] 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

当前目录切分只解决了写入路径隔离的一部分，采集端仍未聚合 dp0/dp1/... 多个子目录，因此 F1/F2 的核心问题还未闭环。建议先让 /metrics 显式遍历各 DP 目录合并采集，再合入。