Load balancer / proxy / router organized around Express/Connect-like middleware.
Distribute is a middleware-based API to expressively perform request routing / load balancing in Node.JS.
var http = require'http'createServerlisten3000srv = require'balance'http;srvuseif reqheadershost == 'blog.mydomain.com'next8000;elsenext;;srvusesomethingAsyncif err return nexterr; // sends a `500` and cleans upnextport host;;;
Requests triggered by the
upgrade event (as a result of the
HTTP header) are handled by prepending the
ws flag each time you call
- Leverages the well-tested
- Simplicity of Express.
- Compatible with connect middleware (eg: qs parser, cookie decoder).
- Middleware makes sticky/session load balancing trivial to write.
- Middleware can perform async tasks. Distribute manages buffers transparently for you.
next parameter can take three signatures:
- no parameters (
next()) will execute the next middleware. If no middleware is available, an error is displayed (refer to the "Default behaviors section")
- port (
- port (
Number), host (
Distribute adds two properties to request objects:
node-http-proxy data buffer.
For WS requests, the first packet of the stream, only present for legacy purposes.
Error object is passed to next, or when no middleware will
handle a given request, the default behavior is to show a
500 Internal Server Error (for HTTP requests) or the socket is ended
(WS requests). In development (ie: NODE_ENV is set to
stack trace is sent along with the error code.
If you want to define custom "error handling middleware", you can do so by adding a function with 4 parameters instead of 3 (in other words, with an arity of 4).
// regular requestssrvusenext;;// ws requestssrvusenext;;
It's not necessary to pass the error to
next to trigger the next error
Request data buffers are cleaned up automatically when:
- a response is produced prematurely instead of proxying. For example
- a socket for an upgrade is
(The MIT License)
Copyright (c) 2011 Guillermo Rauch <email@example.com>
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the 'Software'), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED 'AS IS', WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.