https://github.com/litilexuezha/node-dnslookup
Improve your dns lookup in NodeJS, more customizable.
https://github.com/litilexuezha/node-dnslookup
dns hosts nodejs nslookup optimization
Last synced: 7 months ago
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Improve your dns lookup in NodeJS, more customizable.
- Host: GitHub
- URL: https://github.com/litilexuezha/node-dnslookup
- Owner: LitileXueZha
- License: mit
- Created: 2021-05-13T11:01:52.000Z (over 4 years ago)
- Default Branch: main
- Last Pushed: 2021-05-31T10:18:53.000Z (over 4 years ago)
- Last Synced: 2025-03-05T04:02:06.958Z (7 months ago)
- Topics: dns, hosts, nodejs, nslookup, optimization
- Language: JavaScript
- Homepage:
- Size: 21.5 KB
- Stars: 0
- Watchers: 1
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
Awesome Lists containing this project
README
# node-dnslookup
Improve your dns lookup in NodeJS, more customizable.
#### Features
+ DNS cache in memory
+ Local hosts map like `/etc/hosts`
+ Use specific DNS servers
## Usage
Install via npm.
```shell
npm install --save node-dnslookup
```
Quck examples:
```javascript
const ns = require('node-dnslookup');
https.request('example.org', {
lookup: ns.lookup,
});
// Apply to all requests
ns.use(https.globalAgent);
// With options
new ns.DNSLookup(options).lookup
// Or
ns.use(agent, options);
```
Options table:
|property|description|default|example|
|-|-|-|-|
|hosts|self-defined local hosts|`[]`|`['127.0.0.1 local localhost', '::1 ipv6.local']`|
|servers|DNS servers. Useful for private network|`[]`|`['8.8.8.8']`|
## More
Inspired by `cacheable-lookup`; Related post: [Fixing DNS in Node.js](https://httptoolkit.tech/blog/configuring-nodejs-dns/).
#### Reason
The native [`dns.lookup`](https://nodejs.org/api/dns.html#dns_dns_lookup_hostname_options_callback) is implemented as a synchronous call on libuv's threadpool. So when you have a lot of network requests in short time, the process may be blocked becauseof DNS lookups, even causes itself or other unrelated node scripts hang up and be a "zombie" process.
> No benchmark data proves better performance in production, but it theoretically does. It's not recommanded if no problems come with you.
#### Benchmarks
```log
┌──────────────┬─────────┬─────────┬──────────┬────────┬────────┬──────────┬─────────┬───────────┬───────────┐
│ function │ N │ #1 │ max │ min │ avg │ >10ms(%) │ >1ms(%) │ >0.1ms(%) │ faster(%) │
├──────────────┼─────────┼─────────┼──────────┼────────┼────────┼──────────┼─────────┼───────────┼───────────┤
│ 'dns.lookup' │ 1000000 │ 11.9297 │ 361.3681 │ 0.1868 │ 0.2596 │ 0.0203 │ 0.6732 │ 99.3064 │ │
│ 'ns.lookup' │ 1000000 │ 14.0073 │ 110.6485 │ 0.0004 │ 0.0009 │ 0.0001 │ 0.0053 │ 0.0103 │ 99.986 │
└──────────────┴─────────┴─────────┴──────────┴────────┴────────┴──────────┴─────────┴───────────┴───────────┘
Total: 26:19.123 (m:ss.mmm)
```
Indicators|description
-|-
"N" | run times
"#1" | average cost time of every hostname first lookup
"max" | maximum lookup cost time exclude the first
"min" | minimum lookup cost time exclude the first
"min" | average lookup cost time exclude the first
"faster(%)" | (count of cost time that less than `dns.lookup` minimum value) / total