[RL] Reuse GDR checkpoint transfer handle

[jackyYang6]

Motivation

Avoid repeated CheckpointTransfer initialization during GDR dynamic weight updates. Reusing the initialized handle reduces repeated setup overhead across multiple update steps.

Modifications

• Cache the GDR CheckpointTransfer handle in DynamicWeightManager.
• Lazily initialize the handle on the first GDR weight update.
• Reuse the cached handle for later update_weights_by_gdr calls.
• Destroy and reset the cached handle when an update fails.

Usage or Command

No new user-facing command. Existing GDR weight update flow is unchanged.

Accuracy Tests

Not applicable. This PR only changes checkpoint-transfer handle initialization behavior and does not affect model outputs.

Checklist

• Add at least a tag in the PR title.
• Format your code, run pre-commit before commit.
• Add unit tests. No unit tests added because this is a handle lifecycle optimization for GDR runtime behavior.
• Provide accuracy results. Not applicable; no model output changes.
• 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 86.95652% with 3 lines in your changes missing coverage. Please review.
⚠️ Please upload report for BASE (develop@6d9a8f4). Learn more about missing BASE report.

Files with missing lines	Patch %	Lines
fastdeploy/rl/dynamic_weight_manager.py	86.95%	2 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             develop    #8078   +/-   ##
==========================================
  Coverage           ?   67.52%           
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  Files              ?      475           
  Lines              ?    66907           
  Branches           ?    10317           
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  Hits               ?    45182           
  Misses             ?    18857           
  Partials           ?     2868           

Flag	Coverage Δ
GPU	77.55% <86.95%> (?)
XPU	6.95% <0.00%> (?)

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[PaddlePaddle-bot]

🤖 Paddle-CI-Agent | pr_review | 2026-06-26 11:04:01

📋 Review 摘要

PR 概述：缓存 GDR CheckpointTransfer handle，避免动态权重更新时重复初始化 transfer 句柄。
变更范围：fastdeploy/rl/dynamic_weight_manager.py、tests/rl/test_dynamic_weight_gdr.py
影响面 Tag：[RL]

问题

未发现新的阻塞性问题。PR 规范问题在下面章节报,不要在这里重复

历史 Findings 修复情况

Finding	问题	状态
F1	_destroy_gdr_handle() 吞掉 cleanup() 异常且没有任何日志。	⚠️ 仍存在
F2	缓存的 GDR CheckpointTransfer 没有在 sleep/clear 权重路径释放。	⚠️ 仍存在

📝 PR 规范检查

符合规范。标题使用官方 [RL] Tag，PR 描述包含 checklist §D2 要求的 Motivation、Modifications、Usage or Command、Accuracy Tests 和 Checklist 章节。

总体评价

本轮按风险优先追溯了 GDR handle 创建、复用、异常清理、runner update/clear/sleep 调用链和新增单测。除历史未解决项外，暂未发现新的需要行间评论的问题。

[PaddlePaddle-bot]

🤖 Paddle-CI-Agent | ci_status_monitor | 2026-07-06 15:08:37 UTC+08:00

CI报告基于以下代码生成（30分钟更新一次）:
PR commit: 9238c11 | Merge base: 6d9a8f4 (branch: develop)

---

1 Required任务 : 8/10 通过

总执行（rerun次数）	总任务	✅ 通过	❌ 失败	⏳ 运行中	⏸️ 等待中	跳过
42(0)	42	39	3	0	0	0

任务	错误类型	置信度	日志
Approval	需要 Approval	高	Job
xpu_8cards_case_test / run_xpu_8cards_cases	未知	低	Job

2 失败详情

🔴 Approval — 需要 Approval（置信度: 高）

分析器: builtin approval_required
失败用例: 不适用

用例	错误摘要
不适用	该 Job 需要人工 Approval，完成审批后 CI 才会继续执行。

关键日志:

[FAILURE]: Process completed with exit code 6.

• 根因摘要: 需要人工 Approval
  该 Workflow 处于审批门禁失败状态，不是代码测试失败。完成人工审批后后续 CI 才会继续执行。

修复建议:

1. 请通过人工审批。

关联变更: 无，属于 CI 审批流程。

🔴 xpu_8cards_case_test / run_xpu_8cards_cases — 未知（置信度: 低）

分析器: ci_analyze_unittest_fastdeploy
失败用例: 未获取到结构化失败用例

用例	错误摘要
未知	深度日志未提供 log_file_path、unittest_logs_dir 或 unittest_details，error_snippet 为“日志获取失败，无法提取错误信息”。

关键日志:

[FAILURE]: Process completed with exit code 1.
深度日志获取结果: 日志获取失败，无法提取错误信息。

• 根因摘要: 失败日志不可用，暂无法定位
  fetch_ci_logs(quick=false, job_id=83582376858) 未返回可读取的 log_file_path、unittest_logs_dir 或 unittest_details，返回的 extract_dir 在当前环境不存在。PR 改动集中在 GDR checkpoint transfer handle 复用逻辑及其单测，现有 CI 元数据不足以证明该 XPU 8 卡失败由 PR 代码导致。

修复建议:

1. 先 rerun 该 job 或重新抓取日志；拿到具体失败用例/traceback 后再判断是否与 GDR 动态权重更新改动相关。

关联变更: fastdeploy/rl/dynamic_weight_manager.py:58, fastdeploy/rl/dynamic_weight_manager.py:179, fastdeploy/rl/dynamic_weight_manager.py:209, tests/rl/test_dynamic_weight_gdr.py:186, tests/rl/test_dynamic_weight_gdr.py:254