@cryptotax计算器/xios-cached-dns-resolve

这个图书馆是原作的叉子 axios-cached-dns-resolve 软件包,但添加/更改如下:

• 添加类型安全
• 将模块分辨率改为CJS(从无害环境管理)
• 更改测试跑道从 ava 改为 jest
• 添加对 Redis 的支持作为缓存

关于完整的更改清单,见 变化。 。 。 .

Axios 使用 node.js dns. lookup 来解决主机名称. dns. lookup是同步的,在有限的libuv线程池上执行. 每个轴请求将解析 kubernetes 中的 dns 名称, 开班, 以及云环境, 有意将 TTL 设置为低或为 0 以快速动态更新 . Dns 解析器可以被负载所淹没. DNS 分辨率中存在/ 存在一个错误, 它显示为非常长 dns. lookups in node.js.

从库伯内特 文档

Even if apps and libraries did proper re-resolution, the load of every client re-resolving DNS over and over would be difficult to manage.

这个库使用dns.resolve,并且可以在地址中可选择性地缓存分辨率和圆旋. 缓存大小可配置. 如果启用缓存, 背景线程会用 dns.resolve 而不是每个请求来定期刷新分辨率 . 有一种闲置的 TTL 如果一个地址不再使用, 则驱逐背景更新 . 这个自由代理通过OS解析机制,可以提供进一步的缓存.

目标

• Async 请求 - dns 解析 vs 查找
• 快速 - 本地内存缓存搜索
• 新鲜 - 定期(经常)更新
• 恒定 DNS 负载/纬度与随机负载/可变纬度
• 提供统计和回顾

所需资源

节点14+

开始

npm i -S @cryptotaxcalculator/axios-cached-dns-resolve

使用量

import { registerInterceptor } from "@cryptotaxcalculator/axios-cached-dns-resolve";

const axiosClient = axios.create(config);

registerInterceptor(axiosClient);

使用 arxiosclient 为普通

配置

export const config = {
  disabled: process.env.AXIOS_DNS_CACHE_DISABLE === "true",
  dnsTtlMs: parseInt(process.env.AXIOS_DNS_CACHE_TTL_MS || "5000"), // when to refresh actively used dns entries (5 sec)
  cacheGraceExpireMultiplier: parseInt(
    process.env.AXIOS_DNS_CACHE_EXPIRE_MULTIPLIER || "2"
  ), // maximum grace to use entry beyond TTL
  dnsIdleTtlMs:
    parseInt(process.env.AXIOS_DNS_CACHE_IDLE_TTL_MS || "1000") * 60 * 60, // when to remove entry entirely if not being used (1 hour)
  backgroundScanMs: parseInt(
    process.env.AXIOS_DNS_CACHE_BACKGROUND_SCAN_MS || "2400"
  ), // how frequently to scan for expired TTL and refresh (2.4 sec)
  dnsCacheSize: parseInt(process.env.AXIOS_DNS_CACHE_SIZE || "100"), // maximum number of entries to keep in cache
  // pino logging options
  logging: {
    name: "axios-cache-dns-resolve",
    // enabled: true,
    level: process.env.AXIOS_DNS_CACHE_LOG_LEVEL || "info", // default 'info' others trace, debug, info, warn, error, and fatal
    // timestamp: true,
    prettyPrint: process.env.NODE_ENV === "DEBUG" || false,
    formatters: {
      level: (label: string) => {
        return { level: label };
      },
    },
  },
  redisConfig:
    process.env.AXIOS_DNS_CACHE_USE_REDIS === "true"
      ? {
          url: process.env.AXIOS_DNS_CACHE_REDIS_URL || "localhost:6379",
          password: process.env.AXIOS_DNS_CACHE_REDIS_PASSWORD,
          ttl: parseInt(process.env.AXIOS_DNS_CACHE_REDIS_TTL || "5"), // default 5 seconds
        }
      : undefined,
  cache: undefined as LRUCache<string, DnsEntry> | undefined,
} as Config;

config.lruCacheConfig = {
  max: config.dnsCacheSize,
  ttl: config.dnsTtlMs * config.cacheGraceExpireMultiplier, // grace for refresh
} as LRUCacheConfig;

统计

可通过下列渠道获得统计数据:

getStats()

{
  "dnsEntries": 4,
  "refreshed": 375679,
  "hits": 128689,
  "misses": 393,
  "idleExpired": 279,
  "errors": 0,
  "lastError": 0,
  "lastErrorTs": 0
}

AND

getDnsCacheEntries()

[
  {
    "host": "foo-service.domain.com",
    "ips": [
      "51.210.235.165",
      "181.73.135.40"
    ],
    "nextIdx": 1,
    "lastUsedTs": 1604151366910,
    "updatedTs": 1604152691039
  },
  ...
]

特快统计

import {
  getStats,
  getDnsCacheEntries,
} from "@cryptotaxcalculator/axios-cached-dns-resolve";

router.get("/axios-dns-cache-statistics", getAxiosDnsCacheStatistics);

function getAxiosDnsCacheStatistics(req, resp) {
  resp.json(getStats());
}

router.get("/axios-dns-cache-entries", getAxiosDnsCacheEntries);

function getAxiosDnsCacheEntries(req, resp) {
  resp.json(getDnsCacheEntries());
}