A cacheable
dns.lookup(…)that respects TTL 🎉
Making lots of HTTP requests? You can save some time by caching DNS lookups ⚡
const http = require('http');
const CacheableLookup = require('cacheable-lookup');
const cacheable = new CacheableLookup();
http.get('https://example.com', {lookup: cacheable.lookup}, response => {
// Handle the response here
});const http = require('http');
const CacheableLookup = require('cacheable-lookup');
const cacheable = new CacheableLookup();
cacheable.install(http.globalAgent);
http.get('https://example.com', response => {
// Handle the response here
});Returns a new instance of CacheableLookup.
Type: Object
Default: {}
Options used to cache the DNS lookups.
Type: Keyv adapter instance
Default: new Map()
A Keyv adapter which stores the cache.
Type: number
Default: Infinity
Limits the cache time (TTL in seconds).
If set to 0, it will make a new DNS query each time.
Type: Function
Default: new dns.Resolver()
An instance of DNS Resolver used to make DNS queries.
Type: Object
Type: string
The IP address (can be an IPv4 or IPv6 address).
Type: number
The IP family (4 or 6).
Type: number
Note: This is not present when using the native dns.lookup(...)!
The timestamp (Date.now() + ttl * 1000) when the entry expires.
Note: This is not present when using the native dns.lookup(...)!
The time in seconds for its lifetime.
When options.all is false, then callback(error, address, family, expires, ttl) is called.
When options.all is true, then callback(error, entries) is called.
Type: Array
DNS servers used to make the query. Can be overridden - then the new servers will be used.
The asynchronous version of dns.lookup(…).
Returns an entry object.
If options.all is true, returns an array of entry objects.
Note: If entry(ies) were not found, it will return undefined.
Type: string
Type: Object
The same as the dns.lookup(…) options.
Type: boolean
Default: false
Throw when there's no match.
If set to false and it gets no match, it will return undefined.
Note: This option is meant only for the asynchronous implementation! The synchronous version will always give an error if no match found.
An asynchronous function which returns cached DNS lookup entries. This is the base for lookupAsync(hostname, options) and lookup(hostname, options, callback).
Note: This function has no options.
Returns an array of objects with address, family, ttl and expires properties.
An asynchronous function which makes a new DNS lookup query and updates the database. This is used by query(hostname, family) if no entry in the database is present.
Returns an array of objects with address, family, ttl and expires properties.
Updates interface info. For example, you need to run this when you plug or unplug your WiFi driver.
See the benchmarks (queries localhost, performed on i7-7700k):
CacheableLookup#lookupAsync x 265,390 ops/sec ±0.65% (89 runs sampled)
CacheableLookup#lookupAsync.all x 119,187 ops/sec ±2.57% (87 runs sampled)
CacheableLookup#lookupAsync.all.ADDRCONFIG x 119,666 ops/sec ±0.75% (89 runs sampled)
CacheableLookup#lookup x 116,604 ops/sec ±0.68% (88 runs sampled)
CacheableLookup#lookup.all x 115,627 ops/sec ±0.72% (89 runs sampled)
CacheableLookup#lookup.all.ADDRCONFIG x 115,578 ops/sec ±0.90% (88 runs sampled)
CacheableLookup#lookupAsync - zero TTL x 60.83 ops/sec ±7.43% (51 runs sampled)
CacheableLookup#lookup - zero TTL x 49.22 ops/sec ±20.58% (49 runs sampled)
dns#resolve4 x 63.00 ops/sec ±5.88% (51 runs sampled)
dns#lookup x 21,303 ops/sec ±29.06% (35 runs sampled)
dns#lookup.all x 22,283 ops/sec ±21.96% (38 runs sampled)
dns#lookup.all.ADDRCONFIG x 5,922 ops/sec ±10.18% (38 runs sampled)
Fastest is CacheableLookup#lookupAsync
The package is based on dns.resolve4(…) and dns.resolve6(…).
It is not possible to use
dns.lookup(…)because underlying calls like getaddrinfo have no concept of servers or TTL (caching is done on OS level instead).
- cacheable-request - Wrap native HTTP requests with RFC compliant cache support
MIT