Illyria

The next generation Illyria RPC SDK for node.js in Huaban with ❤️.

Installation

$ npm install --save illyria

Usage

Server

First you should create a server.

var illyria = require("illyria");
var server = illyria.createServer(options);

or

var server = new illyria.Server(options);

options is an optional parameter and may contain:

• maxRetries: default to 10
• retryInterval: default to 5000
• maxListeners: maximum server event / client event listeners count, default to 10
• port: optional, you may specify it in listen
• host: optional, you may specify it in listen
• ...: other options for net.Socket

After the server is created, you may expose or overwrite a module of its events to clients:

server.expose("module", {
    "method": function(req, resp) {
        // ... do sth ...
        resp.send(RESPONSE_MESSAGE);
    }
}, [OPTIONS]);

The code above will expose (may overwrite previous module "module") the whole module "module" with only one method "method" to clients.

And the method "method" will do something and send RESPONSE_MESSAGE back to client who made this request.

req is Request which will be metioned after and resp is Response which will be metioned later.

Attention: OPTIONS is an optional parameter that is an instance of object.

OPTIONS:

• alias: You may specify some alias rules for module or methods. For an example, if your module name is fooBar and the OPTIONS is { alias: [ { module: "upperCamel" } ] }, the module FooBar will be exposed at the same time while fooBar is exposed;

When all modules are exposed, you can let the server listen to a certain port:

server.listen([SERVER_PORT], [SERVER_HOST], callback);

SERVER_PORT and SERVER_HOST are optional when you specified in constructor's option parameter. callback is the callback function when your server listened successfully.

Caution: SERVER_PORT should be an instance of Number and SERVER_HOST should be an instance of String.

With Zookeeper

You can use zookeeper to manage server nodes:

var server = illyria.createServer(OPTIONS, ZOOKEEPER_OPTIONS);

If you had specified ZOOKEEPER_OPTIONS, illyria will use zookeeper to manage this node.

ZOOKEEPER_OPTIONS:

• connectString: a connect string or a connect string's array. Refer here.
• root: this node's root path. Defaults to "/illyria".
• prefix: the node name's prefix. Defaults to "/HB_". So the default whole path is "/illyria/HB_#{node sort}".
• ...: other options refer here.

What Does This Do?

When zookeeper is specified, the server will register for a temporary node under zookeeper.

The content data of that node will be a string like:

{host},{port},{currentClientCount}

For an example, when a server of 192.168.1.88:1234 is created, and zookeeper options is { connectString: foo, root: "/illyria", prefix: "/HB_" }, a node named /illyria/HB_0000000001 will be created, and the content will be:

192.168.1.88,1234,0

After a new client is connected, the content will be changed to

192.168.1.88,1234,1

Request

Request will be passed in the exposed server methods as req.

This kind of object has functions below:

• params(): get the whole param body of message received from client.
• param(key, defaultValue): if params() returns a JSON object, this function may return the value of a certain key with a default value if it has no such key.

Response

Response will be passed in the exposed server methods as resp.

This kind of object has functions below:

• json(data): send a JSON data back to the request client.
  • if there's a key values status and its boolean value is false, server will send back an error message to client with the message in key msg.
  • if there's a key values err or error, server will send back an error message to client with this err or error object.
  • otherwise, server will send back a normal json message to client.
• send(data): send a normal message equals to data back to the request client.
• error(err): send an error message with err back to the request client.

Tip: You may get the client socket wrapper object through both req.socket or resp.socket.

Client

Your client should be created at first:

var illyria = require("illyria");
var client = illyria.createClient(SERVER_HOST, SERVER_PORT, options);

or

var client = new illyria.Client(SERVER_HOST, SERVER_PORT, options);

Be careful that SERVER_PORT must be an instance of Number.

options is an optional parameter and may contain:

• runTimeout: dafault to 10000 (ms)
• maxRetries: default to 10
• retryInterval: default to 5000 (ms)
• ...: other options for net.Socket

Then you may connect to the server:

client.connect(function() {
    // DO SOMETHING AFTER CONNECTED
    // ...
});
 
client.on("error", function(err) {
    console.log(err);
});

Events

Error

client.on("error", function(err) {});

Try Reconnect

client.on("tryReconnect", function(after) {});

Connected

client.on("connected", function() {});

Send a Message to RPC Server

client.send("module", "method", DATA, function(err, data) {
    console.log(err, data);
});

Send a Cast Message to RPC Server

clisent.cast("module", "method", DATA, function(err) {
    console.log(err);
});

Get Current Connect Status

client.connectStatus(); ///< DISCONNECTED, etc.

"module" and "method" are specified by server via server.expose().

DATA may be a number, string, JSON object and so on.

After client received response from RPC server, the callback function will be called. When the server response an error message, the err is the responsed error. Otherwise, data will be responsed via server's resp.send().

With Zookeeper

You can use zookeeper to connect to server automatically with simple load balancing:

var server = illyria.createClient(OPTIONS);

The OPTIONS is the same as it mentioned above on client section.

But it must has a part called zookeeper.

zookeeper:

• connectString: a connect string or a connect string's array. Refer here.
• root: this node's root path. Defaults to "/illyria".
• prefix: the node name's prefix. Defaults to "/HB_". So the default whole path is "/illyria/HB_#{node sort}".
• ...: other options refer here.

eg. { zookeeper: { connectString: "xxx" } }

What Does This Do?

When zookeeper is specified, the client will connect to zookeeper and find all registered servers information which are specifed via root and prefix.

Then it will choose a least connection server to connect.

Benchmark

See wiki/benchmark or may wikis/benchmark for more information.