sg-service v0.0.7

sg-service

A Javascript service manager work with node-zookeeper-client and grpc for Node.js.

This module is not ready for product.

Installation

You can install it using npm:

$ npm install sg-service

Example

1. Create a service manager and add two services

let SgService = require("sg-service");

let serviceMgr = new SgService({
    appName: "app",
    zookeeperConStr: "192.168.73.141:2181,192.168.73.142:2181,192.168.73.143:2181"
});

serviceMgr.addServer("math", {
    async multiPlus(a, b, c) {
        return a+b+c;
    }
});

serviceMgr.addServer("array", {
    async toArray(a, b, c) {
        return [a,b,c];
    }
});

serviceMgr.start();

process.on('SIGINT', () => {
    serviceMgr.shutdown();
    process.exit();
});

2. Create a client and use the service

let SgService = require("sg-service");

let serviceMgr = new SgService({
    appName: "app",
    zookeeperConStr: "192.168.73.141:2181,192.168.73.142:2181,192.168.73.143:2181",
});
serviceMgr.start();
serviceMgr.registerService(["math", "array"]);

let mathService = serviceMgr.getService("math");
let arrayService = serviceMgr.getService("array");
setTimeout(() => {  // there is not service ready event yet, use setTimeout instead
        console.log("mathtest", mathService.call(null, "multiPlus", 1, 2, 3));  // mathtest 6
        console.log("arraytest", arrayService.call(null, "join", 1, 2, 3));  // mathtest [1,2,3]
    }, 2000);

More examples is not ready.

Documentation

SgService(options)

Class function to create a service manager.

Arguments

• options Object - An object to set the manager options. Currently available options are:

  • appName string - Root node name of zookeeper.
  • zookeeperConStr string - Comma separated host:port pairs, each represents a ZooKeeper server.
  • myRpcIP string - IPv4 addr for grpc connection, default is the IP address of network.

Example

let serviceMgr = new SgService({
    appName: "app",
    zookeeperConStr: "192.168.73.141:2181,192.168.73.142:2181,192.168.73.143:2181",
});

SgService

void start()

Start the service, connect to zookeeper.

void shutdown()

Stop the service, disconnect from zookeeper, close grpc connections.

void addServer(serviceName, handler)

Add a service server on this node process.

Argument

• serviceName string - Service name to serve
• handler Object.<string,function> - Service function object

Example

serviceMgr.addServer("math", {
    async multiPlus(a, b, c) {
        return a+b+c;
    }
});

ServiceServer getServer(serviceName)

Get a service server.

Argument

• serviceName string - Service name

void registerService(serviceNames)

Register Services to use, zookeeper will watch the service node and synchronize the detail services nodes to local cache.

Arguments

• serviceNames Array.<string> - Array of service names to regist.

Example

serviceMgr.registerService(["math", "array"]);

Service getService(serviceName)

get Service by name.

Arguments

• serviceName string - Service name.

Example

let mathService = serviceMgr.getService("math");

Example

let mathServer = serviceMgr.getServer("math");

ServiceServer

A service server with some functions

setData(data)

Set data to the service server in this service manager, it can be get by service node in the service.

Arguments

• data * - Some data

Example

mathServer.setData({burn:100});

Service

A service client.

call(node, method, ...args)

Call remote function provided by service servers that added to service manager.

Returns the result of the service function.

Arguments

• node ServiceNode - null to random one, see ServiceNode
• method string - Function name to call
• ...args * - Any arguments, not support Function type.

Example

let result = mathService.call(null, "multiPlus", 1, 2, 3);
console.log("result is", result);

Array. getNodes()

Get the nodes in the services.

Returns the serviceNodes list, see ServiceNode

Example

let mathServiceNodes = mathService.getNodes();

string getName()

Get the name of service.

Example

let name = mathService.getName();
console.log("service name is", name);

ServiceNode

A node in a service, connected to a grpc server of the service server.

call(method, ...args)

Call remote function provided by service servers that added to service manager.

Returns the result of the service function.

Arguments

• method string - Function name to call
• ...args * - Any arguments, not support Function type.

Example

let serviceNode = mathServiceNodes[0];
let result = serviceNode.call("multiPlus", 1, 2, 3);
console.log("result is", result);

getData()

Returns the data set by service server.

Example

let serviceNode = mathServiceNodes[0];
console.log("service node data is", serviceNode.getData());