how do simple mobile game servers are built? - mobile

I'm really new to programming, and I wonder how simple mobile game servers (like flappy bird) are built to store the scores that user made.

If you are new to programming maybe instead of programming your own backend engine is better to use some APIs developed by third party developers. Some examples are on Parse, App42 or Gamedonia. This APIs allows to save data easily and to not have to build your own servers.

The three things you need to know how to do:
Write a program that talks to another program over the internet
Write a program that talks to a database on the local machine
Start a virtual server instance on a service such as AWS and run stuff on it
For a beginner, NodeJS and MongoDB are particularly easy to do this with.
Later it might be a better idea to use an already-made API like Unai mentions, but trying this out yourself first will give you a better understanding of how this all works.

You can also use Facebook scores API for that (how to integrate in unity3d).

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Is it alright to write a software creates a roster for a restaurant with JAVA language?

I need some advice on the project im working for fun during the summer. Say im writing a software that helps creating the roster base on the availiabilities of the staffs. I need some advice on how to implement these items below:
A database that holds the infomation of the staffs (ie.
availiabilities, minimum hours, maximum hours).
The core of the software where the process of arranging staffs on a day base on the database.
A GUI that displays the final version of roster after step 2 above so it can be printed out by the manager.
Im thinking of using Java but not sure how i to implement and connect the database, the core and the GUI together? Can i do everything listed using Java?Can anyone please suggest me a solution or an article for this?
There are many different paths you could follow, depending on what your end goals are.
DO you want to learn Java or are you just trying to practice application development ? I am assuming you are interested in an application that runs on the web.
For me, the best choices are either Java or PHP, but this is largely based on my own experiences. Others might argue that Python or Ruby would be a better to start.
For a Java based solution, you would use: Java JSPs with HTML for the front end (Javascript and JQuery optional); Java (Servlets) for the middle tier; JDBC, JPA, Spring, and/or Hybernate to connect to the DB; MySQL is a good candidate for the DB, but there are other options.
For a PHP based solution, you would use: PHP, HTML for the frond end (Javascript and JQuery optional); PHP for the middle tier (there are frameworks you coulse here as well); PHP to connect to the DB; MySQL is a good candidate for the DB, but there are other options.
If you dont know either, I think PHP is easier to setup and run for beginners, and is the basis for many open source and commercial web applications (e.g., WordPress); but Java is used for most large scale applications.

Apache with Comet Support

I'd like to build a multiplayer web game application in which it supports chat. I presume the application will have to handle hundreds of simultaneous connections.
I'm planning to host my application in a shared web hosting, which has these limitations (most likely similar to PHP + Comet (long-polling) scaling / hosts):
It does not seem I can change the web server. Most likely it's using Apache.
Supports MySQL 5, PHP 5.3.x, Perl, Python, Ruby on Rails, CGI
(To be more precise, I'll be using HawkHost's shared web hosting.)
And here are my result of research, followed by my questions:
Some resources (like Python Comet Server) say that PHP is not good for handling concurrent connections, while Python is better choice. Is this true?
I've tried the long polling technique in PHP (although I don't know whether it's correctly implemented or not, like Comet issue with abandoned open connections) using "Loop endlessly until the data changes." method. This almost works. The remaining problem is that the server process never dies when the browser is closed (the server does not know that the connection has been terminated, and the data never changes). Is there any way the PHP can detect whether the browser has been terminated so that it stops the loop?
I've been looking everywhere to look for answers but still I can't conclude anything. This topic has also been asked on StackOverflow so many times, I'm sorry if I may sound repeating >.<.
Currently I am able to code using PHP, MySQL, and JQuery for JS. I'm still new to the term Comet and Server Push. If necessary, I'm also willing to learn new scripting language like Python.
I appreciate any insights of what scripting language, framework, and techniques to use to start my project.
When you have a shared hosting environment and there are a number of restrictions enforced then it's a good idea to outsource the realtime functionality. I would say this since I work for one such company, Pusher. But I hope others will back me up on this.
When using a hosted solution you can push a notification by making a HTTP request to a RESTful API. The service will then deliver the message to the connected Web Client (browser). The browser does need to include a script tag or use a library that also connects to the hosted service.
The main benefits are:
No installation or maintenance
No need to handle persistent connections - no resource usage
Really simple usage: Script tag in app and call REST API
The hosted solution handles scaling
Also, here's a list of hosted realtime solutions.
So you can use Python. Then you can use Tornado. (psst... facebook uses it)
And I had same problem with open connections. Just don't spend time for search solution in PHP - later you will be sorry. I was. Just use what is made for Comet. If you more prefere JAVA, then there is: CometD.
And for game get a normal hosting. They cheap this days.

Is it possible to create a database driven website with flash?

I am a newbie programmer and i dont yet have any idea of the WEB. I wish to start learning a technology that will allow me to build websites( database driven) i dont know which one to choose. I know some actionscript3 and flash.
Is it possible to create a database driven website using these alone? Or do i need to learn any other technology? If i do then what should i learn? I know j2se for the desktop and oracle SQL/MySQL
please show me a path. Also wanted to know if there is any technology like Wordpress for J2EE/flash
OK so i finally got the feeling that i need to learn PHP anyway along with css and javascript. So it is fine. Also another query. Which CMS should i consider? Wordpress or Joomla?
You can develop a database driven website using Flash, but only in the same sense that you can develop a database driven website using AJAX. That is, you can build the front-end using Flash/ActionScript but the back-end is built using other technologies. Just like working with JavaScript to develop a front-end, from ActionScript you would be communicating with Java or PHP or Python or something on the server using RESTful calls and then actually working with the database in the server-side scripts.
Honestly = this question is too broad and generic, and answers are easily found with some google searches.
That being said = of course you can build a data driven flash site. The one caveat here is that flash itself is fundamentally client-side technology, so we must rely on other remote tech to do the heavy data lifting. The options are profuse.
For example, a developer might create a front facing presentation in Flex, which is the streamlined, data-centric extension of pure flash. His database interactions are written in php, and these are constantly called upon to deliver content to the user.
So - what technologies to use? Whatever you know. And if you don't know, then learn the ones that are closest to what you know.
Finally, although I am a die-hard fan of flash, this type of project (you didn't specify what you had in mind) could be done with many different technologies. So - maybe flash is the right answer, but maybe javascript (ajax) could manage the same thing and do it without the need of plugins.
Yes you can develop database driven site in flash/action script but you still need and back-end technology i recommend you to check WebORB you can develop the back-end using Java, PHP, or .NET In addition you can use Flash Remoting technology Flash/Flex to communicate with a back-end
Flash can't be directly connected to database. You must use another technique which would be "mediator". I have developed Flash game with MySql database and PHP and I recommend you to use this combination. Here is visually presented this kind of communication: http://www.youtube.com/watch?v=gRi-oxjFfCU
yes, it is possible to crate database driven website with flash and action-script. You would get an XML file when you do action script in flash, so you can store nodes of that XML file into database(mysql). You can then create an Admin interface to manage your database contents, that would indirectly change your xml nodes. So basically you can edit the xml file and store it in the database.

nodejs and database communication - how?

I've heard much good about nodejs and writting client-server application with it. But I can't get, for example, when developing IM client-server application, how nodejs server script is supposed to talk to database server to actually store it's data? Or may be I miss something and nodejs server scripts are not supposed to do that? If so, please, push me to correct direction.
I've noticed DBSLayer http://code.nytimes.com/projects/dbslayer/wiki, but it looks like it's still in beta.
You need to grab a module that handles the communication to the database you want. See here for a list of modules for node.js. Popular databases that work well with node.js are MongoDB, CouchDB and Redis.
As stagas says, you can use a module that handles communication if you want to use an external database.
If you want an internal (=embedded) database, you can use one written in javascript you can require like any other module such as NeDB or nStore. They are easier to use and useful if your webapp doesn't need to handle a lot of concurrent connections (e.g. a tool you make for yourself or a small team), or if you write a desktop app using Node Webkit

How to wrap a C library so that it can be called from a web service

We have a library with very complex logic implemented in C. It has a command line interface with not too complex string-based arguments. In order to access this, we would like to wrap the library so that it can be accessed with simple XML RPC or even straightforward HTTP POST calls.
Having some experience with Java, my first idea would be
Wrap the library in JNI/JNA
Use a thin WS stack and a servlet engine
Proxy requests through Apache to the servlet engine
I believe there should already be something simple that could be used, so I am posting this question here. A solution has the following requirements
It should be deployable to a current linux distribution, preferrably already available via package management
It should integrate with a standard web server (as in my example Apache)
Small changes to the library's interface should be manageable
End-to-end (HTTP-WS-library-WS-HTTP) the solution should not incur too much overhead, but reliability is very important
Alternatively to the JNI/JNA proposal, I think in the C# world it should not be too difficult to write a web service and call this unmanaged code module, but I hope someone can give me some pointers that are feasible in regards to the requirements.
If you're going with web services, perhaps Soaplab would be useful. It's basically a tool to wrap existing command line applications in SOAP web services. The web services it generates look a bit weird but it is quite a popular way to make something like this work.
Creating an apache module is quite easy and since your familiar with xmlrpc you should check out mod-xmlrpc2. You can easily add your C code to this apache module and have a running xmlrpc server in minutes
I think you may also publish it as a SOAP based web service. gSoap can be used to provide the service interface out of the library. Have you explored gSOAP? See http://www.cs.fsu.edu/~engelen/soap.html
Regards,
Kangkan
Depends what technology you're comfortable with, what you already have installed and working on your servers, and what your load requirements are.
How about raw CGI? Assuming the C code is stateless between requests, you can do this without modifying the library at all. Write a simple script which pulls the request parameters out of the CGI environment, perhaps sanitises the input, calls the library via the command-line interface, and packages the result into whatever HTTP response you want. Then configure Apache to dispatch the relevant URL(s) to this script. Python, for example, has library support for XML-RPC, and so does every other scripting language used on the web.
Servlets sound like overkill, but for instance if you want multiple requests per CGI process instantiation, and don't feel like getting involved in Apache configuration, then it might be easiest to stick with what you know.
I'm doing a similar thing with C++ at the moment. In my case, I'm writing a PHP module to allow PHP scripts to access the logic in my C++ library.
I can then use whatever format I want to allow the rest of the world to see it - initially it will just be through a PHP web application but I'll also be developing an XML-RPC interface.
If you're going down the JNI route, check out SWIG.
http://www.swig.org/Doc1.3/Java.html
Assuming you have headers to project bindings with, swig is pretty easy to work with.

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