add_memory 返回成功但立即查询同一 memory_id 404

[Memtensor-AI]

问题描述

调用 add_memory 接口返回成功并获得 memory_id，但立即使用相同 memory_id 查询时固定返回 404，预期可以查询到刚写入的数据，实际数据不存在。

复现信息

• trace_id=575fe27de896ca4f095ed3594f57e69f
• xiaoyi:af5452dacec926cf17b86d97
• issue:10a3e370a9306cb018d44213

现象

• add_memory 接口成功返回 memory_id
• 立刻用同一 memory_id 查询返回 404
• 稳定复现

[Memtensor-AI]

🤖 AutoDev has picked up this issue and started working on it.

Task ID: c738ad199edc554f
Working branch: bugfix/autodev-2329-20260902085902328
Target branch: latest dev* branch
Workflow: opsp (analysis → coding → testing → PR)

I will post the PR link here once done. If I need more information, I will ask in the comments.

[Memtensor-AI]

✅ AutoDev task c738ad199edc554f completed.

Summary: Fixed the add_memory → get_memory 404 race condition in async mode.

Root cause: In async mode, add_memory writes fast-mode LongTermMemory nodes and immediately returns their IDs (IDs_A) to the caller. The scheduler's MemReadMessageHandler._process_memories_with_reader would then call fine_transfer_simple_mem which produces brand-new UUID nodes (IDs_B), write those, and hard-delete IDs_A. Any get_memory(IDs_A) call issued after the scheduler ran would return 404 because the original nodes no longer existed.

Fix applied in src/memos/mem_scheduler/task_schedule_modules/handlers/mem_read_handler.py: when fine_transfer_simple_mem produces exactly one enhanced memory per input item (the common 1:1 case), the enhanced item's .id is overwritten with the original node's ID before writing. Neo4j uses MERGE semantics, so the graph node is updated in-place and the caller's handle remains permanently valid. Reused IDs are then excluded from the subsequent delete list so the freshly-updated node is never destroyed. The existing delete-and-replace behavior is fully preserved for 1:N expansions and zero-output cases.

Tests: 4 new unit tests added in tests/mem_scheduler/test_mem_read_handler_id_stability.py covering the 1:1 reuse path (ID assigned, ID not deleted), the 1:N expansion fallback (old ID still deleted), and the zero-output fallback. All 50 scheduler tests pass. Ruff clean.

Base branch: main
Branch: bugfix/autodev-2329-20260902085902328
Commit: b36f301
PR: #2330
Assigned to: @whipser030
Reviewers: @MatthewZhuang, @CarltonXiang, @syzsunshine219, @World-controller