An HTTP proxy which repeats requests to failover backends or returns cached answers in order to successfully answer requests even when the backends are down

npm install -g failoverproxy

Write something like this:

{

    local: {
        address: '0.0.0.0',
        port: 8086
    },
	
    backends: []
}

Now add some backends to the backends array. A backend can be just an URL, the string 'cache' or an object containing host and port. Some examples:

{
    host: '127.0.0.1',
    port: 8087
}

'http://127.0.0.1:8087/'

'cache'

The backend object supports the following properties:

• type - Backend type (server or cache). Defaults to server when a host is specified. Defaults to cache when a path is specified;

The server backends (type: "server) support the following properties:

• proto - Backend protocol (http or https);
• host - The backend hostname;
• port - The backend port; Defaults to 80;
• prefix - The URL prefix to be used on the backend;

The cache backends (type: "cache") support the following properties:

• driver - The cache driver to be used. Defaults to fs, the only cache driver shipped with failoverproxy;
• expireTime - The number of milliseconds that a cache item takes to expire. Supports numbers or the string never;

The fs driver supports the following properties:

• path - The directory to store the cached items;

You can watch for more examples on the examples/ directory.

• httpTimeout - The number of milliseconds to wait for a request on the backend (defaults to 5000);
• httpTestTimeout - The number of milliseconds to wait on a backend test request (defaults to 1000);
• httpMaxSockets - The number of maximum open sockets for each backend (defaults to 256);
• backendWatchInterval - The number of milliseconds of interval to perform HTTP tests requests to backends with status down;
• backendSelector - A function which permits to select the next active backend from a supplied list;
• cache - An object containing the settings to be used for cache when just the string 'cache' is used for backend;
• backends - An array containing backend objects, URLs (as server backends) or the string 'cache' as a cache backend using the cache configuration settings;
• errors - An object containing an index of error codes, containing a document string and an headers object;

$ failoverproxy config_file --debug