Node.js 中的动态配置：超越环境变量
Environment variables work—until they don't. You set RATE_LIMIT=100 in your .env, deploy, and forget about it. Then Black Friday hits. Your API is hammered. You need to drop that limit to 50. Right now.
环境变量有效——直到它们无效。你在 .env 中设置 RATE_LIMIT=100，部署，然后忘掉它。然后 Black Friday 来袭。你的 API 被猛烈攻击。你需要立即将该限制降至 50。
The deploy pipeline takes 12 minutes.
部署管道需要 12 分钟。
This is the moment teams discover the difference between static configuration and dynamic configuration. Static config is baked into your deployment—it changes when you redeploy. Dynamic config lives outside your deployment—it changes when you change it.
这是团队发现静态配置和动态配置之间区别的时刻。静态配置被内置到你的部署中——它在你重新部署时改变。动态配置生活在你的部署之外——它在你改变它时改变。
The Static Configuration Problem
静态配置问题
Most Node.js applications start with environment variables:
大多数 Node.js 应用程序从环境变量开始：
const config = { rateLimit: parseInt(process.env.RATE_LIMIT || '100'), featureNewCheckout: process.env.FEATURE_NEW_CHECKOUT === 'true', cacheMaxAge: parseInt(process.env.CACHE_MAX_AGE || '3600')}
This pattern is fine for truly static values—database URLs, API keys, service endpoints. These values don't change while the application is running, and they shouldn't. But it falls apart for values you need to change quickly:
这种模式适用于真正静态的值—数据库 URL、API 密钥、服务端点。这些值在应用程序运行时不会改变，也不应该改变。但对于您需要快速更改的值，它会失效：
- Rate limits during traffic spikes or incidents
- 速率限制 在流量峰值或事件期间
- Feature flags for gradual rollouts or kill switches
- 功能标志，用于渐进式 rollout 或紧急开关
- Timeout values when downstream services are slow
- 超时值，当下游服务变慢时
- Batch sizes when processing backlogs
- 批处理大小 在处理积压任务时
- Log levels for debugging production issues
- 日志级别 用于调试生产问题
Changing any of these requires a deploy. That means opening a PR, waiting for review, merging, waiting for CI, deploying, and hoping the change actually helps. If it doesn't, repeat the cycle.
更改这些中的任何一个都需要部署。这意味着打开 PR、等待审查、合并、等待 CI、部署，并希望更改真正有效。如果无效，则重复循环。
What Dynamic Configuration Actually Means
动态配置的实际含义
Dynamic configuration has three properties that distinguish it from static config:
动态配置有三个属性使其区别于静态配置：
Changes propagate wi...