group_xinghuo_jinrong/docs/course/jinrong-module-risk/modules/07-concurrency.html

<section class="module" id="module-7">
  <div class="module-inner">
    <p class="eyebrow animate-in">模块 7 · 写侧并发</p>
    <h1 class="module-title animate-in">同一天两笔交易<br>为什么还是一条预警？</h1>
    <p class="module-lead animate-in">
      进程内聚合锁原语（<code>locks.py</code>）把「同一客户、同一聚合 key」串行化；L3 监测画像写入服务（<code>profile_l3.py</code>）用
      <code>computed_at</code> 乐观锁防丢更新。指挥 AI 改写路径时，先分清<strong>悲观锁（串行）</strong>和<strong>乐观锁（版本戳比对）</strong>各管哪一段。
    </p>

    <div class="screen animate-in">
      <h2>两层锁 · 各管什么</h2>
      <table style="width:100%; border-collapse:collapse; margin:1.5rem 0; font-size:0.95rem;">
        <thead>
          <tr><th style="text-align:left;padding:0.5rem;">职责</th><th style="text-align:left;padding:0.5rem;">代码入口</th><th style="text-align:left;padding:0.5rem;">机制</th></tr>
        </thead>
        <tbody>
          <tr>
            <td style="padding:0.5rem;vertical-align:top;">预警同日聚合串行</td>
            <td style="padding:0.5rem;vertical-align:top;">预警处置与聚合服务（<code>alert_service.py</code>）+ 锁原语（<code>locks.py</code> · <code>run_locked</code>）</td>
            <td style="padding:0.5rem;vertical-align:top;">单进程 <code>threading.Lock</code>；拿锁超时降级执行，冲突由锁内重查兜底</td>
          </tr>
          <tr>
            <td style="padding:0.5rem;vertical-align:top;">L3 写侧防覆盖</td>
            <td style="padding:0.5rem;vertical-align:top;">L3 写入（<code>profile_l3.py</code>）+ 仓储更新（<code>risk_repository.update_l3</code>）</td>
            <td style="padding:0.5rem;vertical-align:top;">乐观锁：<code>WHERE computed_at = :expected</code>，失败重读重试（最多 3 次）</td>
          </tr>
          <tr>
            <td style="padding:0.5rem;vertical-align:top;">处置 + 审计同事务</td>
            <td style="padding:0.5rem;vertical-align:top;">人工处置（<code>handle_alert</code>）+ 风控仓储（<code>risk_repository</code>）</td>
            <td style="padding:0.5rem;vertical-align:top;">状态变更与 audit 同连接提交（B7 挂账⑦ 已收口）</td>
          </tr>
        </tbody>
      </table>
      <div class="callout callout-accent">
        <strong>不做：</strong> 风控线不接 L1/L2 画像 Redis 热缓存（归客服/顾问）；L3 读侧已有 <code>profile:l3:{customer_id}</code> cache-aside + 写后 DEL。
      </div>
    </div>

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        <div class="translation-code">
          <span class="translation-label">锁原语 · 预警聚合 key 示例</span>
          <pre><code><span class="code-line"><span class="code-comment"># alert_service：同日同客户事件类预警</span></span>
<span class="code-line">run_locked(</span>
<span class="code-line">  <span class="code-string">f"agg:event:{customer_id}:{today}"</span>,</span>
<span class="code-line">  <span class="code-keyword">lambda</span> locked: _merge_or_insert(...),</span>
<span class="code-line">)</span>
<span class="code-line"></span>
<span class="code-line"><span class="code-comment"># profile_l3：同一客户 L3 upsert</span></span>
<span class="code-line">run_locked(<span class="code-string">f"l3:{customer_id}"</span>, _write_with_optimistic_retry)</span></code></pre>
        </div>
        <div class="translation-english">
          <span class="translation-label">白话</span>
          <p>想象收银台<strong>叫号器</strong>：同一客户、同一天的「首单聚合」必须排队进窗口，窗口里再查「今天是否已有单」——两笔并发进来也不会开出两张重复首单。</p>
          <p>L3 则是<strong>贴便签前先对表上的时间戳</strong>：若别人刚改过，你的 UPDATE 打不中，就重读再合并（只升不降监测档）。</p>
        </div>
      </div>
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      <h2>群聊：并发两笔 · 聚合与 L3</h2>
      <div class="chat-window" id="chat-risk-m7">
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          <div class="chat-message" data-msg="0" data-sender="t1" style="display:none">
            <div class="chat-avatar" style="background:#D94F30">T1</div>
            <div class="chat-bubble">
              <span class="chat-sender" style="color:#D94F30">trade #1</span>
              <p>引擎出单 → 请求 <code>run_locked(agg:event:…)</code></p>
            </div>
          </div>
          <div class="chat-message" data-msg="1" data-sender="t2" style="display:none">
            <div class="chat-avatar" style="background:#E87A62">T2</div>
            <div class="chat-bubble">
              <span class="chat-sender" style="color:#E87A62">trade #2</span>
              <p>同时到达 → 在锁外等待或超时降级；锁内重查并入同一 <code>risk_alert</code></p>
            </div>
          </div>
          <div class="chat-message" data-msg="2" data-sender="l3" style="display:none">
            <div class="chat-avatar" style="background:#B83E24">L3</div>
            <div class="chat-bubble">
              <span class="chat-sender" style="color:#B83E24">profile_l3</span>
              <p>upsert 前读 <code>computed_at</code> → UPDATE 带 expected → 失败则重试</p>
            </div>
          </div>
          <div class="chat-message" data-msg="3" data-sender="audit" style="display:none">
            <div class="chat-avatar" style="background:#D4A843">审</div>
            <div class="chat-bubble">
              <span class="chat-sender" style="color:#D4A843">audit</span>
              <p>处置 handle：改 status + 写 audit_log <strong>同一事务</strong>（避免「状态变了没审计」）</p>
            </div>
          </div>
        </div>
        <div class="chat-typing" id="chat-risk-m7-typing" style="display:none">
          <div class="chat-avatar" id="chat-risk-m7-typing-avatar">…</div>
          <div class="chat-typing-dots"><span class="typing-dot"></span><span class="typing-dot"></span><span class="typing-dot"></span></div>
        </div>
        <div class="chat-controls">
          <button class="btn chat-next-btn">下一条</button>
          <button class="btn chat-all-btn">全部播放</button>
          <button class="btn chat-reset-btn">重播</button>
          <span class="chat-progress"></span>
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      <h2>数据流：写侧三条线</h2>
      <div class="flow-animation" data-steps='[
        {"highlight":"flow-w1","label":"交易事件进引擎 → alert_service 拿 agg 锁"},
        {"highlight":"flow-w2","label":"锁内查锚点 → 首单 INSERT / 后续 append 事件","packet":true,"from":"1","to":"2"},
        {"highlight":"flow-w3","label":"profile_l3 upsert：run_locked + 乐观锁 retry","packet":true,"from":"2","to":"3"},
        {"highlight":"flow-w1","label":"officer handle：status + audit 同事务","packet":true,"from":"3","to":"1"}
      ]'>
        <div class="flow-actors">
          <div class="flow-actor" id="flow-w1"><span class="flow-actor-icon">🔒</span><span>聚合锁</span></div>
          <div class="flow-actor" id="flow-w2"><span class="flow-actor-icon">📋</span><span>risk_alert</span></div>
          <div class="flow-actor" id="flow-w3"><span class="flow-actor-icon">📊</span><span>L3 + audit</span></div>
        </div>
        <p class="flow-step-label">点击「下一步」</p>
        <div class="flow-controls">
          <button class="btn flow-next-btn">下一步</button>
          <button class="btn flow-reset-btn">重来</button>
        </div>
      </div>
    </div>

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      <div class="quiz-container" id="quiz-risk-m7">
        <div class="quiz-question-block"
             data-correct="option-b"
             data-explanation-right="对。L1/L2 Redis 热缓存是客服/顾问画像线；风控写侧是 L3 + 聚合锁 + 审计同事务。"
             data-explanation-wrong="风控不做 L1/L2 Redis；L3 已有 cache-aside，写侧靠锁与乐观锁。">
          <h3 class="quiz-question">指挥 AI「给风控加 L1 Redis 热读」合理吗？</h3>
          <div class="quiz-options">
            <button class="quiz-option" data-value="option-a" onclick="selectOption(this)">
              <div class="quiz-option-radio"></div><span>合理，四个 Agent 画像都应同一套 Redis</span>
            </button>
            <button class="quiz-option" data-value="option-b" onclick="selectOption(this)">
              <div class="quiz-option-radio"></div><span>不合理；风控只需 L3 cache-aside，L1/L2 归客服/顾问</span>
            </button>
            <button class="quiz-option" data-value="option-c" onclick="selectOption(this)">
              <div class="quiz-option-radio"></div><span>合理，用 Redis 替代所有 MySQL 写</span>
            </button>
          </div>
          <div class="quiz-feedback"></div>
        </div>
        <button class="quiz-check-btn" onclick="checkQuiz('quiz-risk-m7')">检查答案</button>
        <button class="quiz-reset-btn" onclick="resetQuiz('quiz-risk-m7')">重做</button>
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</section>