https://github.com/abellsmythe/request-time
Request Middleware with time metrics
https://github.com/abellsmythe/request-time
javascript metrics node-module nodejs request time
Last synced: about 1 month ago
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Request Middleware with time metrics
- Host: GitHub
- URL: https://github.com/abellsmythe/request-time
- Owner: abellsmythe
- License: mit
- Created: 2019-09-06T14:00:04.000Z (almost 7 years ago)
- Default Branch: master
- Last Pushed: 2019-09-09T19:59:20.000Z (over 6 years ago)
- Last Synced: 2025-10-03T16:01:57.772Z (8 months ago)
- Topics: javascript, metrics, node-module, nodejs, request, time
- Language: TypeScript
- Homepage:
- Size: 91.8 KB
- Stars: 0
- Watchers: 1
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
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README
# request-time
> Timings for HTTP requests
Understanding and measuring HTTP timings helps us to discover performance. bottlenecks in client to server or server to server communication.
#### Timings explained
- `DNS Lookup`: Time spent performing the DNS lookup. DNS lookup resolves domain names to IP addresses. Every new domain requires a full round trip to do the DNS lookup.
- > There is no DNS lookup when the destination is already an IP address.
- `TCP Connection`: Time it took to establish TCP connection between a source host and destination host. Connections must be properly established in a multi-step handshake process. TCP connection is managed by an operating system, if the underlying TCP connection cannot be established, the OS-wide TCP connection timeout will overrule the timeout config of our application.
- `TLS handshake`: Time spent completing a TLS handshake. During the handshake process endpoints exchange authentication and keys to establish or resume secure sessions.
- > There is no TLS handshake with a not HTTPS request.
- `Time to First Byte (TTFB)`: Time spent waiting for the initial response. This time captures the latency of a round trip to the server in addition to the time spent waiting for the server to process the request and deliver the response.
- `Content Transfer`: Time spent receiving the response data. The size of the response data and the available network bandwidth determinates its duration.
## Installation
NPM:
> `npm install @abellsmythe/request-time`
## Usage
```javascript
'use strict';
const https = require('https');
const timer = require('@abellsmythe/request-time').default;
const request = https.get('https://google.com');
const timings = timer(request);
request.on('response', response => {
response.on('data', () => {
// Do something
});
response.on('end', () => {
console.log(timings);
});
});
```
```javascript
{
start: 20019170.414002,
socket: 20019171.943738,
dnsLookup: 20019182.811348,
connect: 20019194.637675,
tlsHandshake: 20019245.32874,
upload: 20019246.615841,
response: 20019284.613933,
end: 20019288.80115,
error: undefined,
phases:
{
wait: 1.5297359973192215,
dns: 10.86761000007391,
tcp: 11.826326999813318,
request: 51.9781660027802,
firstByte: 37.998091999441385,
download: 4.187217000871897,
total: 118.38714800029993
}
}
```
## API
### timer(request)
Returns: `Object`
- `start` - Time when the request started.
- `socket` - Time when a socket was assigned to the request.
- `dnsLookup` - Time when the DNS lookup finished.
- `tlsHandshake` - Time when the secure connection is done.
- `connect` - Time when the socket successfully connected.
- `upload` - Time when the request finished uploading.
- `response` - Time when the request fired the `response` event.
- `end` - Time when the response fired the `end` event.
- `error` - Time when the request fired the `error` event.
- `phases`
- `wait` - `timings.socket - timings.start`
- `dns` - `timings.dnsLookup - timings.socket`
- `tcp` - `timings.connect - timings.dnsLookup`
- `request` - `timings.upload - timings.connect`
- `firstByte` - `timings.response - timings.upload`
- `download` - `timings.end - timings.response`
- `total` - `timings.end - timings.start` or `timings.error - timings.start`
If something is not measured yet, it will be `undefined`.
> **Note**: The time is a `number` representing the milliseconds without elapsing since the UNIX epoch.
> **Note**: `request-time` uses `process.hrtime()` from node as it's not a subject of clock drift