Always Online

Always online is an realtime message sync service which is based on socket.io.

Feature

Realtime message sync, only support broadcast in room right now
Support message storage, using redis as memory database
Support Android/iOS/Web/WeChat mini program, which is benifit from socket.io open source project
Support cluster and horizontal scalability, using redis sub/pub feature

Dependencies

socket.io
redis
mongodb

Usage

Install npm dependencies
```
 cd always-online
 npm install
```

Install redis/mongodb (Mac users)

 brew install redis
 brew install mongodb

Start redis/mongo server
```
 redis-server
 mongod --dbpath {path}
```

Create Test Users

 post {uid: 1000} to http://{hostname}:3000/user/create_token, token will be returned

Start Server
```
 cd always-online
 node index.js all
```

Socket.io build in Message Protocol

Please refer socket io client

connect
connect_error
connect_timeout
error
disconnect
reconnect
reconnect_attempt
reconnecting
reconnect_error
reconnect_failed
ping
pong

Custom Message Protocol

Status Code

0: success, other: failed

authenticate

 Request:
 {uid: 1000, token: xxxx}
 Response:
 {status: 0, data: 'auth success'}

join

 Request:
 {roomId: 1000} //Note: roomId can not be 0
 Response:
 {status: 0, data: 'xxxx'}

 Note:
 if request is {roomId: 1000, dummy: true}, the client can peep the room info, and is invisible to other clients in the room.

remote_join
```
 {uid: 1000}
```

msg

 {data: json-object, storage: 0|1|2, msgId: string or integer}
 0: insert
 1: update
 2: ignore

leave
```
 no data needed, just emit command
```
remote_leave
```
 {uid: 2000}
```
remote_disconnect
```
 {uid: 2000}
```

sync

 Request: {offset: 0, encoding: 'gzip'}
 Response: {next: 1, offset: 500, data: [], encoding: 'gzip'}
 next:
 	0: no data to get
 	1: has more data, need do sync with offset again until next is 0

remote_sync
```
 {uid: 1000}
```

Example (javascript):

var socket = io('ws://localhost:3000');
socket.on('connect', function() {
  console.log('connect to server, and start auth');
  socket.emit('authenticate', {uid:'123456', token:'123456'});
});

socket.on('authenticate', function(msg) {
  if (msg.status == 0) {
	var roomId = 1000;
    console.log('auth success, and start join room: %d', roomId);
    socket.emit('join', {roomId: roomId})
  } else {
    console.log('auth failed')
  }
});

socket.on('join', function(msg) {
  if (msg.status == 0) {
	console.log('join success and start sync');
	socket.emit('sync', {offset: 0});
  } else {
	console.log('join failed');
  }
});

socket.on('sync', function(msg) {
	// handle msg
	if (msg.next == 1) {
		console.log('get more data, offset: %d', msg.offset);
		socket.emit('sync', {offset: msg.offset});
	} else {
		console.log('sync data finish');
	}
});

socket.on('remote_join', function(msg) {
  console.log('remote join uid:', msg.uid);
});

socket.on('remote_leave', function(msg) {
  console.log('remote leave uid:', msg.uid);
});

socket.on('kickout', function(msg) {
  console.log('kickout');
});

socket.on('disconnect', function(msg) {
  console.log('disconnect');
});

......

Rest API

common response struct

{
	meta: {
		status: 0|1|...,
		msg: ''
	},
	data: {
		... // response data
	}
}

Account API

Need called from business server to register account for security.

Status Code:

var errMsg = {
  0: 'success',
  1: 'user exists',
  2: 'operation failed',
  3: 'server error',
  4: 'param error',
  5: 'user not exists'
};

create_token

http://{hostname}:4000/user/create_token

Method: POST

Request:
{uid: '1000'} //Note: uid can not be 0

Response data:
{
	uid: '1000',
	token: 'xxxxxx'
}

refresh_token

http://{hostname}:4000/user/refresh_token

Method: POST

Request:
{uid: '1000'}

Response data:
{
	uid: '1000',
	token: 'xxxxxx'
}

Admin API

use those api to debug

stat

http://{hostname}:3000/admin/monitor/stat?uid=xxx&token=xxx

Method: GET

Request:
uid: xxx
token: xxxx

Response data:
{
	online_user_count: 2,
	online_room_count: 1,
	...
}

room_users

http://{hostname}:3000/admin/monitor/room_users?roomId=xxx&uid=xxx&token=xxx

Method: GET

Request:
uid: xxx
token: xxxx
roomId: xxxx

Response data:
{
	users: [
		{uid: xxx},
		{uid: xxx}
	]
}

room_msgs

http://{hostname}:3000/admin/monitor/room_msgs?roomId=xxx&uid=xxx&token=xxx

Method: GET

Request:
uid: xxx
token: xxxx
roomId: xxxx

Response:
{
	msgs: [
		{
			"data":{
				"data":"4444",
				"storage":1,
				"msgId":"touch_begin"
			},
			"ts":1530009108,
			"uid":"4000"
		}
	],
	"offset":1,
	"next":0
}

system push

http://{hostname}:3000/admin/system/push?uid=xxx&token=xxx

Method: POST

Request:
{
	roomId: xxx,
	content: your msg
}
Response data:
none

system config

http://{hostname}:3000/admin/system/config?uid=xxx&token=xxx

Method: POST

Request:
{
	forceUserAuth: true | false
}
Response:
none

clear room msgs

http://{hostname}:3000/admin/system/clear_room_msgs?uid=xxx&token=xxx

Method: POST

Request:
{
	roomId: 1000
}
Response:
none

Stress Test

cd test/stree-test
./run.sh

TODO

stress test(P1)
unit test, interface(P1)
msg (P2)
management console

bdtian / always-online