I'd like to build a 2-player turn based game with an authoritative server to manage the game state/logic. The flow I have in mind is something like:
Players are subscribed to a unique game channel (via pubnub/pusher/something similar)
Players submit their turns over HTTP directly to the game server
The server runs the game logic and publishes the result to the game's channel (which both players are subscribed to)
The client handles the response and renders the outcome
matchmaking kind of confuses me though. Any suggestions?
Is that the "right" way of using a pub/sub service in this scenraio? Is there a better approach (something other than polling the server constantly)?
This is a heated topic at our office! I've been using PubNub as an authoritative game server using creative choice of channel names. It works like this:
Run a node.js server (doesn't have to be node; can be anything) that serves your content, and also acts as an authoritative entity.
When a client connects, generate a UUID (can be done either server-side or client-side) and have both the client and server listen on that channel (something like "my_game_[UUID]").
Because no other clients know this channel name, the client and server can communicate freely on this channel.
The server can talk to everyone, and clients can perform secure actions through the server and communicate with each other using an "unsecure" vanilla pubnub channel.
Your proposal sounds great and is the "right" way. The challenge you face is shared from the beginning of the computer epoch, where synchronizing data is a requirement between multiple devices such as a mobile smartphone. Polling is SLOW and expensive (and does not make sense for a large number of players). Multiplayer games is a great example need to pair players and provide game rooms. Your solution is to:
Create a Game Lobby, where players can create game rooms and join game rooms.
Create an Auto-Pair of players (Quick Join) [Recommended]
You may solve this technical challenge with products such as Socket.IO and some other open source options. However you want to just build your game rather than focus on deploying a Node.JS server and hooking it up to Express.
Instead use a Cloud Service like PubNub, PusherApp or Beacon Push. Utilize the Pub/Sub API to synchronize users in a multiplayer environment easily.
Related
I'm creating a game with HTML5 and javascript, but am having trouble finding a way to get networking working.
What I want is for one instance of the game to listen on a Websockets/http stack, while the other instances connect to it.
So far, I'm yet to find any way of doing it that doesn't require additional plugins or online services. (ie: Flash or silver light opening the socket and pumping messages back - Something that isn't acceptable for mobile, or an online server like Player.IO, which while much better than Flash, wouldn't work for Wifi networks that are disconnected from the Internet)
While the latter option is a compromise I'm willing to make, I was wondering if it's one I need to make, or if I could survive without it.
Well, if I understand what you are trying to, hope to be right.
Client One:
Plays game, listens to incoming data from Client Two
Client Two:
Plays game, connects to Client One
I'm guessing it's a P2P game? If this is the case, I think you want to look at WebRTC.
Otherwise, peer-to-peer is not really possible unless you run a mediator service that both clients connect to and handle it as a dispatcher.
I've been looking into sockjs-tornado recently and am working on a chat function for a social networking site. I'm trying to get a feel for common methods used in building scalable multiroom chat functionality. I'll outline a couple of the methods I've thought of and I'd like to get feedback. What methods are used in the real world? What are the advantages and disadvantages to these methods?
Prereqs:
running tornado
using sockjs-tornado lib
sockjs-client lib for js
Everything else is open.
Methods I've considered:
For loop
This seems like the simplest way to go. You create a user class that subscribes to certain room classes. The user sends a message class that contains a room id and the server redirects the message in the loop only to users that have subscribed to that room. This seems to me to be by far the worst because the complexity is obviously at least linear. (Imagine 500 users connected at once to 5 chat rooms each.)
Multi-tasking/multiple server instances
This also seems like a bad idea because you could have 500 server instances running at any time on... different ports? I'm really not sure on the implementation of this method.
Native support
Now granted, a lot of libraries have this built in such as socketio. However that's not an option due to the sole node.js support. (I'm on tornado server.) Socks in particular does not have built in support for multiple "rooms".
Conclusion
I'm looking for resources/case studies, and industry standards. Any help would be appreciated.
I would just use a message queue server like RabbitMQ with a fanout exchange as each "chat room".
You can see an example of using a fanout exchange in Python here.
The Pika AMQP library works with Tornado, too.
The advantage with using a message queueing system is that you can have users connected to different Tornado processes on different servers while still being in the same "room", giving you high availability on the HTTP layer.
RabbitMQ also has HA capabilities (although not the greatest).
Basically I want make a social game like poker, in which multiple players gets connected.
But I don't want server side interaction.
So my idea was to make one person's browser acts like server and other acts as client.
Person A's browser will hold the data( client side DB) and communicate with person B via web sockets or something.
I am not sure if two browsers can some how connected with sockets. Either web sockets(HTML5) or any flash plugin which can help to IP to IP connection. Is it possible somehow?
As of now I am not even sure how users will connect for starting the game. I may need to put server for initial connection.
Currently you cannot do this with web browsers because they cannot act like a server. It will probably be possible in the future though: Chrome is experimenting with a Socket implementation (this is an experimental feature in Canary releases that is disabled by default). Node.js has already (partially) been ported using chrome.socket.
With Flash, it is possible to create p2p multi player games since version 10, but you still need a central server to setup the initial connections between players. There's a library for it here: http://www.flashrealtime.com/p2p-game-lib/.
Be aware that p2p multi player games make it easier for players to cheat, because the authority lies with one or multiple players, and not with a central server.
It's not possible for a browser to accept a websocket request so a server is necessary for you to handle such a request. For how to set up a websocket server, I recommend socket.io that is based on node.js. It's very easy to use and it's only javascript that is a language that web developers get used to.
I've created a simple game where 2 players make a simultaneous choice in each round, and the winner of the round is determined by a set of rules specific to the game. Sort of like how Rock Paper Scissors works.
I'd like to be able to offer this game online where 2 players can find and play against each other. There would be some central server to arbitrate the game, and then each player would interact with the game using some game client of his choice that we would provide (i.e. web-based, mobile-based, Flash, etc).
Obviously, a player could also play against a computer opponent that we could provide. I'd also like to have the capability to allow programmers to submit computer programs that they've written to act as players and play against other programs in some sort of tournament.
I realize that the specifics of my game would certainly need to be written from scratch, but it seems that all of the work that the servers would have to do to communicate with the clients and maintain the state of the game has probably been done many times before. This is probably the bulk of the work.
Does anyone have any ideas for how this could be done quickly and easily? Are there servers available with some sort of standard interface to drop new games into? Is there some sort of open source game server? How would you go about doing this?
Seeing as the clients only communicate with the game server occasionally (as opposed to continuously), a web framework should be able to serve as your "basic game server". While web frameworks may be made for providing "web pages", they can certainly be (ab)used to serve as request handlers.
This certainly doesn't force you to make the game a browser game; standalone game clients can be made easily, and they can communicate with your game server using basic http. I also heard this thing called Ajax is pretty nifty for such things.
Not only will you find a lot of ready-made http-based servers, as an added bonus, there is a lot more documentation on how to work with Web 2.0®©™ than "game servers". You just need to know that you want a web framework that lets you easily manage sessions and receive/respond to requests and a client library that does likewise.
As an added aside, "maintaining the state of the game", as you put it, falls 100% within the domain of the actual game logic. But many web frameworks come with good database support, and will surely be useful for this kind of thing.
What is a good framework to build a multiplayer game in Actionscript?
I want to create a multiplayer 2D shooter like Asteroids on the Blackberry Playbook; my main concern is latency - a shooter wouldn't be fun if the bullets are super-jerky and unexpectedly hit people.
I'm guessing that a UDP-based framework would be the best. Can anyone point me to the right direction?
There are many things you can use off the shelf but the basic setup is very simple but you have a few options.
The most common is server push, things like Flash Media Server, LiveCycle Data Services from Adobe or other tools like SmartFoxServer can do this. With this setup the server saves the connections to everyone that connects to the server and passes or "pushes" applications state to the people connected every time the data changes in the application.
Another option is called long pulling, this can be done with any web server really. How this works is the data stores the state of the application, when the application starts it calls the server, when it responds the client calls the server again.
There are a few other ways to do it but these are the most common. But this has nothing to do with protocol like HTTP, UDP, AMF, XMPP, or whatever else. The protocol is the format that the data is sent. With these out of the box servers they normally output a few of these but the fastest formats are binary like AMF but not always the best, there are advantages to each, because each gives you different features for keeping track of things.
If you are talking about have a game that takes over the world that has millions of users then you need to think about scaling and what happens when you need two or 100 servers and how do they talk to each other. But for now keep in mind that the more the server does the slower it will get, if you are sending small amounts of data it will be able to handle more users. Stick with making one efficient server and worry about that later if you get there.
You also need to thing about what server side programming language you want to mess with if any. Some services don't let you do anything, these normally cost money and don't do as much. Adobe likes Java but there are servers that output all of these protocols in most every language. My favorit lately has been Node.js a super fast way to run JavaScript on the server. Node.js has a built in HTTP server but it is just as easy to create a simple server that sends basic text through a Socket or XMLSocket. A server like this will easily handle many thousands of users. There are many games that use Socket.IO and if you want to see a simple example of what I'm talking about you can check out this.
Assuming you want to use Flash/Flex and not Java (Blackberry/Android) or native SDKs for Playbook -
There is a book as an inspiration: http://www.packtpub.com/flash-10-multiplayer-game-essentials/book it uses Pulse SDK at the server side. But you could use an own sockets-program on the server side. I use Perl as TCP-sockets server (sends gzipped XML around) in a small card game but this wouldn't work for your shooter.
Flash does not support UDP out of the box
But there is peer-to-peer networking protocol RTMFP in the upcoming Flash Media Server Enterprise 4 (price is out of reach for mere mortals)
So your best bet is to buy an Amazon-service for RTMFP then you can pay-per-use and stay scalable...
You can either do a constant post/get request with the server to get data for the game, but for a multiplayer shooter i'd surgest SmartFoxServer: http://www.smartfoxserver.com/
Out of the box, Adobe AIR supports UDP through datagram packets.
http://help.adobe.com/en_US/air/reference/html/flash/net/DatagramSocket.html
I couldn't find a particular networking API for flash, but perhaps you can build one. Libgren is open source and you can use that for reference.
You can also look into RTMFP though it's focus is on transmitting audio/video and some messages (through TCP I think).