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可搜索的结构化日志

输出带请求关联信息的 JSON 日志。

可搜索的结构化日志 是 CoddyKit 上的免费 MCP Academy 课时。这是第 2 节课，共 4 节。你可以在下方免费阅读本课时的完整内容 — 然后在浏览器中使用内置代码编辑器和全天候 AI 导师进行实践。这是 MCP Academy 学习路径的一部分，你的进度在网页和 CoddyKit 应用中同步。 MCP Academy 课程共包含 4 节课。

本课时的部分内容尚未翻译，以英文显示。

Logs You Can Actually Use

Plain text logs read fine to a human but fight you at scale. Structured logs store each event as data, so machines can filter and search them fast. 🔎

Why JSON Wins

Emit each log line as a JSON object. Every field becomes searchable, so you can query by tool, status, or duration without fragile text parsing.

Anatomy of a Log Event

A good event carries a timestamp, a level, a message, and context fields. Together they tell you what happened, when, and why.

{"ts": "2026-01-01T10:00:00Z",
 "level": "info",
 "msg": "tool called",
 "tool": "search"}

Pick Sensible Levels

Use log levels with intent: debug for detail, info for normal flow, warning for trouble, error for failures. Levels let you turn noise up or down.

The Correlation ID

Give each request a unique correlation ID and stamp it on every log it produces. Now one search pulls the full story of a single call.

Generate an ID

A UUID makes a fine correlation ID: it is unique enough to never collide across requests.

import uuid

request_id = str(uuid.uuid4())
print(request_id)

Log to stderr, Not stdout

Over stdio, stdout carries the MCP protocol itself. Always send logs to stderr so they never corrupt the JSON-RPC messages.

Python's logging Module

Python's built-in logging module gives you levels and handlers for free. Point a handler at stderr and you are halfway there.

import logging, sys

logging.basicConfig(stream=sys.stderr,
                    level=logging.INFO)
log = logging.getLogger("mcp")

Add Fields, Not Strings

Resist stuffing values into the message text. Pass them as extra fields so each one stays its own searchable column later.

log.info("tool finished",
         extra={"tool": "search",
                "ms": 42})

Never Log Secrets

Logs travel and persist, so redact tokens, keys, and personal data before writing them. A leaked secret in a log is a real breach. 🔒

Keep One Line Per Event

Write one JSON object per line. This line-delimited format is what log shippers and search tools expect to ingest cleanly.

Quick Check

One detail trips up many MCP authors.

Recap

You learned to log as searchable JSON: one event per line, useful levels, a correlation ID, redacted secrets, and output on stderr. 📋

常见问题解答

「可搜索的结构化日志」课时是免费的吗？

是的 — 「可搜索的结构化日志」的完整文本可在网页上免费阅读。要进行交互式练习（内置代码编辑器和全天候 AI 导师）并解锁 MCP Academy 课程的其余内容，请升级到 CoddyKit PRO。 MCP Academy 课程共包含 4 节课。

「可搜索的结构化日志」这节课中我会学到什么？

输出带请求关联信息的 JSON 日志。你通过在浏览器中直接运行的动手代码来练习 MCP Academy，全天候 AI 导师会在你学习这节课的过程中回答你的问题。

学习 MCP Academy 需要有经验吗？

无需任何先前经验。CoddyKit 上的 MCP Academy 课程适合初学者到高级学习者，你可以从这里开始或从头开始，按照自己的节奏学习。这是第 2 节课，共 4 节。

「可搜索的结构化日志」课时需要多长时间？

大多数 CoddyKit 课程大约需要 5–10 分钟。每节课都很精短且互动，所以你能稳步进步，并在网页和应用中从离开的地方继续。

我能在这节 MCP Academy 课中编写并运行代码吗？

能。每节 MCP Academy 课都包含内置代码编辑器，你可以在浏览器中直接编写并运行真实代码，并获得即时 AI 反馈 — 无需本地设置。

此课程中的所有课时

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