bug: ghost trace in episode.trace_ids_json causes infinite rescore loop (590 calls, 14.5 RMB wasted)

[7889545]

Summary

A ghost trace ID () was added to an episode's but never existed in the table. This caused to return indefinitely, triggering 590 reward rescore calls over 5 days and wasting ~14.5 RMB on LLM calls.

Root Cause

1. Ghost trace creation

The episode was reopened with . During the follow-up merge, was called which directly overwrites without validating that trace IDs actually exist in the table.

// episodes.js line 80-82
appendTrace(id, traceIds) {
    appendTrace.run({ id, trace_ids_json: toJsonText(traceIds) });
    // No validation that traceIds exist in traces table!
}

2. Reward traceCount mismatch

loads traces via which only returns existing traces:

// reward.js line 48-52
const traces = traceIds.length > 0
    ? deps.tracesRepo.getManyByIds(traceIds).sort(...)
    : [];

This returns 11 traces (ghost excluded). After scoring: reward.traceCount = 11.

3. Dirty check compares against episode.traceIds.length

// memory-core.js line 1003-1006
const traceCount = reward.traceCount;
if (typeof traceCount === number) {
    return traceCount !== (ep.traceIds?.length ?? 0);
    // 11 !== 12 → true → dirty forever!
}

4. Infinite loop

runs every 10 minutes, finds the episode dirty, rescores, gets 11 vs 12 mismatch, episode stays dirty. Repeat 590 times.

Evidence

Episode: ep_95n61b3jzycd
trace_ids_json count: 12 (including ghost tr_xhbp6c9p450r)
tr_xhbp6c9p450r in traces table: 0 (does not exist)
reward.traceCount: 11
episodeRewardIsDirty: true (traceCount mismatch)
Reward calls: 590 over 5 days (06-18 to 06-22)

Suggested Fixes

1. appendTrace validation: Validate trace IDs exist before appending
2. Dirty check resilience: Compare against actual existing trace count, not episode.traceIds.length
3. Rescore retry limit: Add max retry count per episode to prevent infinite loops
4. Ghost trace cleanup: Add startup scan to remove orphaned trace IDs from episodes

Related Issues

• memos-local-plugin: large merged episodes can trigger L2/L3/skill-evolution storm and stall OpenClaw sessions #1755 — large merged episodes can trigger L2/L3/skill-evolution storm (same infinite rescore pattern)

Environment

• MemOS: v2.0.20
• Agent: hermes
• OS: Windows 11