构建 ActionScript游戏服务器，支持超过 15000并发连接

Building an ActionScript Game Server with over 15,000 Concurrent Connections

Renaun Erickson

1

Basic MMO Game Architecture

• Clients• Servers• Databases• Networking

2

MMO Network Considerations

• Protocols (TCP, UDP, HTTP)• Firewalls• Latency• Packet Size• Data Schema

3

Have to be able to create large number of connections that can

send packets at a reasonable rate and bandwidth

4

Socket Implementations

• Check each file descriptor each frame– Select, poll

• Slow for large number of connections• OS Optimized

– Epoll, kqueue, /dev/poll, pollset, I/O Completion Ports

• OS specific fast implementations• Event based libraries

– Libevent and libev• Fast for large number of connections• Portable code, hides OS specific implementations

5

Server Configuration

• Tell OS to allow large number of file descriptors

• Tell OS how much ram for each file descriptor

• Tell OS buffer sizes for network protocols• Tell OS what ports range to use, only 65k

ports per IP

6

Flash on the Client and Server

• Many MMOs in China use Flash as the Client

• Server naturally has MMO game logic• Put game logic on server for security• Many benefits of using the same

language on client and server

Is ActionScript on the server possible?

7

ActionScript on the Server

• Flash Player Dissected– Core – VM, Primitives, ActionScript syntax– APIs – C/C++ classes implementing rich Flash

Player API and features

• Tamarin– Open sourced core parts of the Flash Player– No rich API or features, you have to write

them yourself

8

Tamarin Projects

• Thane (part of Whirled SDK by ThreeRings)– http://wiki.whirled.com/Whirled_SDK

• Redtamarin (by zwetan and others)– http://code.google.com/p/redtamarin/

• PushButton Engines Network component by Ben Garney– https://github.com/PushButtonLabs/

PBNetworking

9

Case Study: SpellTraction

10Design By: Garth Braithwaite http://www.garthdb.com/ @garthdb

Live Demo and Source Code

• http://renaun.com/serveras/test• http://renaun.com/serveras/spelltraction/• https://github.com/renaun/

ActionScriptGameServerExamples

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Server Setup

• Game Server– Amazon EC2 Medium Server– 64 bit Ubuntu OS– Running two game instances

• Main• Load Test

• Load Test Server– Amazon EC2 Medium Server– Custom test scripts

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Server Code

• Redtamarin– Created ServerSocket.as – libev socket

implementation– Compile ActionScript files into ActionScript

Byte Code (abc files)– Command line redtamarin shell runs the abc

files

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Server ActionScript Code

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function loopHandler():void{

if (!ss.listening)ss.listen("10.111.33.190", 12122);

elseserverBrain.beat(); // Game Tick

}

var serverDispatcher:SocketServerNerveDispatcher = new SocketServerNerveDispatcher();

var serverBrain:ServerBrain = new ServerBrain();var serverNerve:ServerNerveSystem

= new ServerNerveSystem(serverBrain, serverDispatcher);serverBrain.addNerve(serverNerve);var ss:ServerSocket

= serverDispatcher.createServerSocket(serverNerve);ss.loop.add(loopHandler);ss.start(250);

Libev Socket Implementation

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bool ServerSocketObject::_listen(Stringp host, const int port){            struct socket_io w_accept;        StUTF8String hostUTF8(host);    const char* hostAddr = hostUTF8.c_str();        if( (w_accept.fd = socket(PF_INET, SOCK_STREAM, 0)) < 0 ) return false;    int flags = fcntl(w_accept.fd, F_GETFL, 0);    fcntl(w_accept.fd, F_SETFL, (flags > 0 ? flags : 0) | O_NONBLOCK);             sockaddr_in addr;    memset(&addr, 0, sizeof(addr));    addr.sin_family = AF_INET;    addr.sin_addr.s_addr = inet_addr(hostAddr);    addr.sin_port = htons(port);    int status = bind(w_accept.fd, reinterpret_cast<struct sockaddr *>(&addr), sizeof(addr));    if (status != 0) return false;            _socket = w_accept.fd;    if (listen(w_accept.fd, 2) < 0) return false;    w_accept.socketObject = this;        

    // Initialize and start a watcher to accepts client requests   ev_io_init(&w_accept.io, accept_cb, w_accept.fd, EV_READ);   ev_io_start(loop_ev, &w_accept.io);   ev_loop(loop_ev, 0);     return true;}

Linux Kernel Configurations

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/etc/sysctl.confnet.core.rmem_max = 33554432net.core.wmem_max = 33554432net.core.rmem_default = 1048576net.core.wmem_default = 1048576net.core.optmem_max = 33554432net.ipv4.tcp_rmem = 4096 4096 33554432net.ipv4.tcp_wmem = 4096 4096 33554432net.ipv4.tcp_mem = 786432 1048576 26777216net.ipv4.tcp_max_tw_buckets = 360000net.core.netdev_max_backlog = 30000net.ipv4.ip_local_port_range = 2048 65535net.ipv4.tcp_window_scaling = 1net.ipv4.tcp_no_metrics_save = 1net.core.somaxconn = 131072fs.file-max = 131072

/usr/include/linux/limits.hNR_OPEN = 65536

/etc/security/limits.conf*                soft    nofile          65535*                hard    nofile          65535

17

Client Code

Client

Server

Shared Code

18

renaun@adobe.com

http://github.com/renaun

@renaun

http://renaun.com/blog

Q / A