I'm planning on creating a browser based RTS game using ASP.NET and MySQL.
I was wondering if there is a way to do this without having a central server running all the time - i.e. if all commands can be completed client side when a player logs on and performs an action, and then the database keeps a record of this.
Thanks
Simply put, no, it's a bad idea. Mostly for one of the main rules of creating an online game: Never trust the client.
Now, there's nothing technical to prevent you from doing this, but plenty of limitations you'd have to work around, and because of the aforementioned rule, it wouldn't be worth it.
Related
I want to use the forge viewer as a preview tool in my web app for generated data.
The problem I have is that the model derivative API is sometimes slow sometimes fast.
I read that this happens because the files are placed in a queue and being processed subsequentially.
In my opinion, this can be solved by:
Having the extraction.update webhook also tell me where I am in the queue. So I can inform my users with better progress information. Or when the queue is too long I can not stop the process.
Being able to have a private queue. I have no problem paying more credits if necessary.
Being able to generate svf2 files on my own server.
But I don't know if any of these options are possible. Or if there is another workaround.
Yes, that could be useful. I logged that request in our system: DERI-7940
Might be considered later on, but no plans currently
I'm not aware of any plans for that
We're always working on making the translation service better, but unfortunately, I cannot tell when it will meet your requirements - including the implementation of the webhook feature you mentioned.
SVF2 is specifically for very large models - is that what you are working with? If not, then I'm quite certain that translating to SVF would be faster.
Our company has people in every catastrophic event here in the U.S. and parts of Canada. An example is they were quite prevalent in Katrina immediately after the event.
We are constructing an application to improve their job in the field which may be either ASP.NET or WPF, and the disconnect requirement makes us believe it will be a WPF application. Our people need to be able to create their jobs, provide all of the insurance and measurement data, and save it as if in the database whether or not the internet is available.
The issue we are trying to get our heads around is that when at catastrophic events our people need to be able to use our new application even when the internet is not available. (They were offline for 3 days in Katrina)
Has anyone else had to address requirements like this and suggestions on how they approached functioning on small-footprint devices while saving data as if they were still connected to the backend services and database? We also have to incorporate security into this as well, and do it well enough that their entered data loads into the connected database without issues.
Our longterm goal is to also provide this application for Android and IPad Tablet devices as well as laptops. Our initial desire for ASP.NET was it gave us an immediate application for the tablet environment. In the old application they have, they run a local server, run remote connections on the tablets and run the application through terminal server. Not pretty. Not pretty.
I feel this is a serious question that is not subjective so hopefully this won't get deleted.
Our current architecture on the server side is Entity Framework with a repository pattern, WCF services to satisfy CRUD requests returning composite data transfer objects, and a proxy for use by the clients.
I'm interested in hearing other developers' input and this design puzzle.
Additional Information Added to the Discussion
Lots of good information provided!!! I'll have to look at Microsoft Sync for sure. For the disconnected database I would be placing only list tables (enumerations) in the initial database. Jobs and, if needed, an item we call dry books, will be added for each client we are helping. (though I hope the internet returns by the time we are cleaning and drying out the homes) These are the tables that would then populate back to the host once we have a stable link. In the case of Katrina we also lost internet connectivity in our offices which meant the office provided no communication relief for days as well.
Last night I realized that our client proxy is the key to everything working! The client remains unaware of the fact that it is online or offline and leaves the synchronization process within that library. We are discovering how much data we are talking about today. I also want to make it clear that ASP.NET was a like-to-have but a thick client (actually WPF with XAML) may end up being our end state.
Now -- for multiple updates. The disconnected work will be going to individual homes by a single franchise. In fact our home office dispatches specific franchises to specific events. So we have a reduced likelihood (if any) of the problem of multiple people updating a record. The reason is that they are creating records for each job (person's home/office/business) and only that one franchise will deal with it. Of course this also means that if they are disconnected for days that the device that creates the job (record of who, where, condition, insurance company, etc) is also the only device that knows of the job. But that can be lived with. In fact we may be able to have a facility to sync the franchise devices on a hub.
I'm looking forward to hearing additional stories of how you've implemented your disconnected environment.
Thanks!!!
Looking at new technology from Microsoft
I was directed to look at a video from TechEd 2012 and thought I might have an answer. The talk was on using ASP.NET and MVC4 along with 2 libraries for disconnected behavior. At first I thought it would be great but then as it continued it worried me quite a bit.
First the use of a javascript backend to support disconnected I/O does not generate confidence. As a compiler guy (and one who wrote two interpretive languages) I really do not like having a critical business model reliant upon interpretive javascript. And script at that! It may be me but it just makes me shudder.
Then they show their "great"(???) programming model having your ViewModel exist as just javascript. I do not care for an application (asp.net and javascript) that can be, and may as well be (for lack of intellisense ) written in notepad.
No offense meant to any asp lovers, but a well written C# program that has been syntactically and type checked gives me stronger confidence in software than something written with a hope and prayer that a class namespace has been properly typed without any means of cross check. I've seen too many hours of debugging looking for a bug that ended up in a huge namespace with transposed ie in it's name. I ran my thought past the other senior developers in my group and we are all in consensus on this technology.
But we continue to look. (I feel this is becoming more of a diary than a question) :)
Looks like a perfect example for Microsoft Sync Framework
http://msdn.microsoft.com/en-us/sync/bb736753.aspx
A comprehensive synchronization platform that enables collaboration
and offline access for applications, services, and devices with
support for any data type, any data store, any transfer protocol, and
any network topology.
I often find that building a lightweight framework to fit my specific needs is more beneficial to me than using an existing one. However, always look at what's available and weigh the pros and cons before making that decision.
I haven't use the Microsoft Sync Framework, but it sounds like that's a good one to research first. If you have Sql Server Standard (or some other version other than the Express version) then replication might also be an option.
If you want to develop your own homegrown solution, then be sure to put lastupdated and dateadded fields on any tables that need to stay in sync. It doesn't 'sound' like your scenario will be burdened by concurrency issues (i.e. if person A and B both modify a field at the same time, who wins?). If that's the case then developing your own lightweight solution will be pretty straightforward.
As Jeremy pointed out, you will need a way to get the changes. In addition to using a web service, you can also use WCF which is similar to a web service in some ways. But my personal bias would be towards just accessing a SQL server remotely over the internet. The downside of that solution is added security concerns, while the upside is decreased development overhead (i.e. faster/easier development now and less maintenance over time). Also, the direct SQL solution is also assuming that this is an internal application... that you're in charge of all development and not working with 3rd parties who need access to your data and wouldn't be allowed to access it this way.
Not really a full answer but too much for a comment.
I have two apps one that synchs one way and the other two way.
I do a one way synch to client for disconnected operation. At the server full SQL Server and at the client Compact Edition. TimeStamp is a prefect for finding any rows that needs to be synched. I also don't copy the whole database as some of the largest table are non nonessential. The common use is the user marks identified records they want to synch.
If synch does what you need great +1 for Jakub. For me I don't have the option to synch the whole MSSQL both based on size and security.
Have another smaller application that synchs two way but in this case it has regions and update are only within the region. So a region only synchs their data and in disconnected mode they can only add new records. Update to an existing records must be performed in connected mode. That was mangeable. In that case MSSQL for the master and used XML for the client.
No news to you but the hard part of a raw synch is that two parties may have added or revised the same record.
I am just getting in to the more intricate parts of web development. This may not be in the best place. However, when is it best to get load balancing for a web project? I understand that it depends on good design/bad design as to how many users you can get to visit a site without it REALLY effecting the performance. However, I am planning to code a new project that could potentially have a lot of users and I wondered if I should be thinking off the bat about load balancing. Opinions welcome; thanks in advance!
I should not also that the project most likely will be asp.net (webforms or mvc not yet decided) with backend of mongodb or pgsql(again still deciding).
Load balancing can also be a form of high availability. What if your web server goes down? It can take a long time to replace it.
Generally, when you need to think about throughput you are already rich because you have an enormous amount of users.
Stackoverflow is serving 10m unique users a month with a few servers (6 or so). Think about how many requests per day you had if you were constantly generating 10 HTTP responses per second for 8 hot hours: 10*3600*8=288000 page impressions per day. You won't have that many users soon.
And if you do, you optimize your app to 20 requests per second and CPU core which means you get 80 requests per second on a commodity server. That is a lot.
Adding a load balancer later is usually easy. LBs can tag each user with a cookie so they get pinned to one particular target. You app will not notice the difference. Usually.
Is this for an e-commerce site? If so, then the real question to ask is "for every hour that the site is down, how much money are you losing?" If that number is substantial, then I would make load balancing a priority.
One of the more-important architecture decisions that I have seen affect this, is the use of session variables. You need to be able to provide a seamless experience if your user ends-up on different servers during their visit. Session variables won't transfer from server to server, so I would avoid using them.
I support a solution like this at work. We run four (used to be eight) .NET e-commerce websites on three Windows 2k8 servers (backed by two primary/secondary SQL Server 2008 databases), taking somewhere around 1300 (combined) orders per day. Each site is load-balanced, and kept "in the farm" by a keep-alive. The nice thing about this, is that we can take one server down for maintenance without the users really noticing anything. When we bring it back, we re-enable our replication service and our changes get pushed out to the other two servers fairly quickly.
So yes, I would recommend giving a solution like that some thought.
The parameters here that may affect the one the other and slow down the performance are.
Bandwidth
Processing
Synchronize
Have to do with how many user you have, together with the media you won to serve.
So if you have to serve a lot of video/files to deliver, you need many servers to deliver it. Let say that you do not have, what is the next think that need to check, the users and the processing.
From my experience what is slow down the processing is the locking of the session. So one big step to speed up the processing is to make a total custom session handling and your page will no lock the one the other and you can handle with out issue too many users.
Now for next step let say that you have a database that keep all the data, to gain from a load balance and many computers the trick is to make local cache of what you going to show.
So the idea is to actually avoid too much locking that make the users wait the one the other, and the second idea is to have a local cache on each different computer that is made dynamic from the main database data.
ref:
Web app blocked while processing another web app on sharing same session
Replacing ASP.Net's session entirely
call aspx page to return an image randomly slow
Always online
One more parameter is that you can make a solution that can handle the case of one server for all, and all for one :) style, where you can actually use more servers for backup reason. So if one server go off for any reason (eg for update and restart), the the rest can still work and serve.
As you said, it depends if/when load balancing should be introduced. It depends on performance and how many users you want to serve. LB also improves reliability of your app - it will not stop when one system goes crashing down. If you can see your project growing to be really big and serve lots of users I would sugest to design your application to be able to be upgraded to LB, so do not do anything non-standard. Try to steer away of home-made solutions and always follow good practice. If later on you really need LB it should not be required to change your app.
UPDATE
You may need to think ahead but not at a cost of complicating your application too much. Do not go paranoid and prepare everything to work lightning fast 'just in case'. For example, do not worry about sessions - session management can be easily moved to SQL Server at any time and this is the way to go with LB. Caching will also help if you hit some bottlenecks in the future but you do not need to implement it straight away - good design (stable interfaces), separation and decoupling will allow for the cache to be added later on. So again - stick to good practices, do not close doors but also do not open all of them straight away.
You may find this article interesting.
I'm looking to create a webpage that will reflect the status of one of my company's servers automatically. Frequently there will be a minor error that only lasts 2-3 minutes, and it would be great to have this reflected on a self-generated page, which might prevent 50-60 unhappy clients from calling in simultaneously and asking what's wrong.
I'm not quite sure where to begin - would anyone have a suggestions for good resources to study? Programming examples? I'm not referring to the basics of writing an ASP.NET page, of course, but rather process interaction in Windows.
Thanks.
To pull this off, you'd need a separate page that essentially runs server diagnostics, otherwise the page wouldn't know if it was up or down. Also, the page would need to be isolated from the sort of problems that are kill other people's requests, such as cache hit problems, memory starvation, high CPU usage, insufficient bandwidth. So ideally the diagnostics would run in a separate app-pool, separate virtual directory, separate machine.
Many of the interesting diagnostics would require a WMI call, but some you can get from the My.Computer namespace.
Also, are you going to do this on every server, or do you want one web server to display the status of several different servers?
It also depends on the type of errors your servers are encountering.
If they are going down completely, or are losing internet connection, then pinging them after an interval of time will let you know if they are up or not.
If you have a specific process running on a server that becomes unavailable, that can be a little more tricky.
Your best bet is to find a way to do a simple request from the services/applications that are important and see if you get a response, if you do, the server is likely up, if not, then it is likely not.
Anything you can do to reduce the number of support calls you get is a good idea, but I'd also focus some time and try to figure out why your servers are going down so often.
Also, telling your users that the server is down, but not giving a reason why may not give the effect you are looking for. Users will still be confused and frustrated when they can't get their work done.
I know you were looking to build a webpage to display the server diagnostics, but there are plenty of server monitoring tools that produce webpages for an easy dashboard view of the history.
A quick google returned the following link:
http://www.webdesignbooth.com/10-really-useful-server-monitoring-tools/
I have a flash based game that has a high score system implemented with a SOAP service. There are prizes involved and I want to prevent someone from using FireBug or similar to discover the webservice path and submit fake scores.
I considered using some kind of encryption on the data but am aware that someone could decompile the swf and work out how I did it.
I also considered using an IP whitelist but since the incoming data will come from the users IP and not the servers that won't work. (I'm sure I'm missing something obvious here...)
I know that there is a tried and tested solution for this, but I don't seem to be asking google the right questions to get to it.
Any help and suggestions will be appreciated, thank you
What you want to achieve is impossible. You can only make it harder for people to do. The best you can do is to use encryption and encrypt the SWF it self, which usually causes higher filesize and poorer performance.
The safest method is to evaluate or even run the whole game on the server. You can try to determine whether what the client sends you is possible at all. Rather than making sure people use your client, you're making sure people play the game according to your rules.
greetz
back2dos
All security is based on making things hard. It never makes things impossible. How about having your game register with a separate service when it starts up. It could use client information to build some kind of special code that would be unique for each iteration of the game. The game could morph the code in a way that would be hard to emulate. Then when the game is over the score gets submitted with the morphed code and validated on the server side.