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

$3

``
npm install nsa
`

$3

` javascript

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

` javascript
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)
];
`

$3

* 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)