NSA

NSA sees all, because NSA is the Networked Status Aggregator.

The idea is simple: NSA sends hartbeat messages over network sockets (currently only UDP) and the nsa-server displays running services on a web interface (and, in the future, does other stuff with them).

NSA is as simple as possible: Clients just send heartbeats and the NSA Server displays new clients on the go.

NSA Client

Install

npm install nsa

Usage

var nsa = require("nsa");

var agency = new nsa({
    server: "udp6://[::1]:30826", // nsa server
    service: "example",           // service name; default: filename of main module
    node: "example",              // name of the node; default: hostname
    interval: "10s",              // interval between heartbeats
    secret: "verysecurestring"    // secret shared with nsa-server
});

/* send a single heartbeat */
agency.ping();

/* start sending heartbeats every $interval */
agency.start();

// stop sending heartbeats
agency.stop();

// tell the nsa server to stop caring about this service
agency.end();

// send data
agency.data({data:"json"});

// send structured data
agency.data([{
    id: "1",         // id for data set (required)
    value: 1,        // value or values (required)
    label: "foo",    // display label (optinal)
    vis: "bar",      // visualisation (optional): text, bar, chart, ring, icon, badge
    color: "#f00",   // color (depending on visualisation)
    unit: "%",       // unit (depending on visualisation)
    range: [0,100],  // value range (depending on visualisation)
    collect: 100,    // number of previous values to collect (depending on visualisation)
},{
    ...
}]);

// set alert level
agency.alert(0);

Message Format

var message = [
    0,                 // message format version
    0,                 // message type (0=heartbeat,1=retire,2=data,3=alert, ...)
    0,                 // sequence number of message
    "example.service", // name of the service
    "example.host",    // name of the node
    10000,             // number of microseconds till next message
    [data]             // data (optional)
];

Message Types

• 0 - Heartbeat Ping
• 1 - Retire
• 2 - Unstructured Data (Data Object in Data Field)
• 3 - Alert (Level 0-5 in Data Field)
• 4 - Authenticate ([hash,salt]) in Data Field
• 5 - Structured Data (Array of Data Objects in Data Field)
• 6 - Authentication Requst (Sent by Server, Challenge in Data Field)