Proxy utility to bundle a batch of calls in one request. Using the batchelor utility reduces HTTP overhead, network round-trip delay time and helps to keep your API design clean.
###Features:
- Server side parallel request processing.
- Persistent request for Web Socket facade.
npm install batchelorjs
configure the batchelor object.
- maxConcurrentJobs - integer containing the number of maximum concurrent jobs (default:50)
- logger - object for logging porpouse (default: empty logger).
- whiteList - an array containing a list of allow host for processing the request (default: *, meaning allow all host/urls).
- request_default_values - Object containing the default values per request in case they are not passed
- method - string containing default HTTP method for the request - Possible values "GET" or "POST"
- timeout - integer containing the number of milliseconds to wait for a request to respond before aborting the request (default: 1000).
- ip - string of the client that request the batching job. (default: "unknown").
- headers - object containing the headers of the client that request the batching job
- body || data - string that will be pass in case of POST request
- strictSSL - requires SSL certificates be valid, used in request module (optional - default:true)
{
maxConcurrentJobs: 10,
logger: "console"
},
request_default_values: {
method: "GET",
timeout: 10000,
ip: "unknown",
headers: {},
data: ""
},
whiteList: ["*"]
}
job- A single request object or array of single requests [required]callback(err, results)- callback method when finish processimg job [required]
- The callback argument gets 2 arguments:
err- error object, if an error occur, null otherwiseresults- an JSON object containing the result/s of the job
An object holding a single or array of requets, to be batch in the request
{
"name": "REQUEST_1",
"method": "GET",
"url": "jsonresponser.herokuapp.com/api/json/users",
"timeout": 1000
}
[
{
"name": "REQUEST_1",
"method": "GET",
"url": "jsonresponser.herokuapp.com/api/json/users",
"timeout": 1000
}
,
{
"name": "REQUEST_2",
"method": "POST",
"url": "jsonresponser.herokuapp.com/api/json/users",
"timeout": 1000
}
]
An object representing a single batch of request. The request must have the following
name- identifier of the item, the name is used as reference. Names must be UNIQUE! [required]url- URL that calls the item. Possible GET parameters are also given here [required]method- possible values areGETorPOSTor whatever methods the called API supports [required]encoding- the encoding of the item (default:UTF8) [optional]retries- number of retries if the timeout is reach (default:2) [optional]headers- the headers that the item uses [optional]body || data- the parameters that the item uses when the method is POST are given here [optional]timeout- number of milliseconds to wait for a request from the API to respond before aborting the request, if this parameters is not provided we use timeout from the config.json file [optional]isOnCloseRequest- flag indicating if the item should be called when the connection is droped, used when using web socket facade (default:false) [optional]persistent- flag indicating if the item should be called in persistent way, used when using web socket facade(default:false) [optional]persistentDelay- number of delay between persistent items in milliseconds, used when using web socket facade (default:5000) [optional]
var exp_app = express();
var compression = require('compression');
var bodyParser = require('body-parser');
var exp_router = express.Router();
exp_app.use(compression());
exp_app.use(bodyParser());
var batchelor = require('batchelorjs');
var configuration = {
"maxConcurrentJobs": 10,
"logger": console,
"request_default_values": {
"method": "GET",
"timeout": 10000,
"ip": "unknown",
"headers": {},
"data": ""
},
"whiteList": ["*"]
};
batchelor.configure(configuration);
exp_router.post("/", function (req, res, next) {
batchelor.execute(req.body, function (err, results) {
if (err) {
console.log("Error occur");
}
else {
res.send(JSON.stringify(results));
}
});
});
exp_app.use("/", exp_router);
exp_app.listen(5050);
var WebSocketServer = require('ws').Server;
var wss = new WebSocketServer({port: 5050});
var batchelor = require('batchelorjs');
var configuration = {
"maxConcurrentJobs": 10,
"logger": "console",
"request_default_values": {
"method": "GET",
"timeout": 10000,
"ip": "unknown",
"headers": {},
"data": ""
},
"whiteList": ["*"]
};
batchelor.persistent.configure(configuration);
ws.on("message", function (data) {
batchelor.persistent.execute(data,
function (err, results) {
ws.send(JSON.stringify(results));
});
});
- The following requests example, will send the 3 requests
- batchelor will process the 3 request and will return the response when:
- reqular request - its reqturned from given URL
- persistent requests - every
persistentDelaymilliseconds, if there is a cahnge in the response - onClose request - once the connection is dropped from client
var job = [
{
name: "regular_request",
url: "jsonresponser.herokuapp.com/api/json/users"
method: "GET",
timeout: 5000,
},
{
name: "persistent_request",
url: "jsonresponser.herokuapp.com/api/json/users"
method: "GET",
timeout: 5000,
persistent: true
persistentDelay: 5000
},
{
name: "onclose_request",
url: "https://www.domain.com/item/2"
method: "POST",
retries: 5,
timeout: 5000,
isOnCloseRequest: true
}
];
var ws = new WebSocket("wss://yourdomain/path");
ws.onopen = function (ws) {
document.getElementById("connectionStatus").innerHTML = "Connected";
ws.send(JSON.stringify(job));
};
ws.onmessage = function (event) {
document.getElementById("responseFromServer").value = event.data;
};
{
regular_request:{
data: {name: "myname1", id: 1},
statusCode: 200,
headers: {"content-type":"application/json"}
},
{
persistentRequest:{
data: "",
headers:{"server":"Cowboy","connection":"keep-alive","x-powered-by":"Express","content-type":"application/json; charset=utf-8","content-length":"116","etag":"W/\"74-1635811801\"","date":"Mon, 12 Jan 2015 09:53:37 GMT","via":"1.1 vegur"
},
"statusCode":200,
"cancelId":"jobName_37"
}
}
}
Having in the response in the client cancelId we can send another request to the server and cancel the specific persistent request like:
var cancelMessage = {
"cancelId":"jobName_1",
"requestName": "persistentRequest"
};
ws.send(JSON.stringify(cancelMessage));
var job = {
persistentJob: true,
requests: [
{
name: "persistent_request_1",
url: "https://jsonresponser.herokuapp.com/api/json/users",
method: "GET",
timeout: 5000
},
{
name: "persistent_request_2",
url: "https://jsonresponser.herokuapp.com/api/json/users",
method: "GET",
timeout: 5000
}
]};
ws.send(JSON.stringify(job));
- In order to cancel job, we need to pass only the cancelId withou any requestName, like:
var cancelMessage = {
"cancelId":"jobName_1",
};
ws.send(JSON.stringify(cancelMessage));