I am looking for a way to transfer a lot of files over a long period of time from a client to a server.
The connection between the client and the server is not reliable and slow.
I thought about using the FTP protocol. I saw the netftp client.
I now need a ftp server in .net also.
The most important feature that I need is reliable connection resuming. Something that I can rely on to just start and end over a period of time reliably.
I didn't find many ftp servers that were written in c#.
Thank you.
you can use Background Intelligent Transfer Service in windows.
http://msdn.microsoft.com/en-us/library/bb968799(v=vs.85).aspx
Use BITS for applications that need to:
Asynchronously transfer files in the foreground or background.
Preserve the responsiveness of other network applications.
Automatically resume file transfers after network disconnects and computer restarts.
a .net wrapper is available for BITS - http://sharpbits.codeplex.com/
Related
I have an application in C# that is a TCP server listening to a port. GPS devices connect to this port. The application is accepting the TCP client and creating a new thread for each client. The client ID in maintained in a hash table that is updated when a client is connected. this was all working fine until around 400 units. Once the number of units increased, the server was unable to handle all connections. The connections are being continuously dropped and once in awhile leads eating up the server CPU and memory and brings it down. Work around was to open another instance of the TCP server listening to a different port and diverted some units to that port. Currently some 1800 units are somehow running in 8 different ports. The server is extremely unstable and units are still unable to stay connected. Facing too many issues on a daily basis. Also using remoting to send settings via the remoting port - this is working only sometimes.
Please help by giving a solution for TCP socket/threading/thread pooling etc. that is both scalable and robust and can in a single port.
This TCP server is running in Windows server 2008 R2 Enterprise with IIS7 and SQL server 2008.
Processor: Intel Xenon CPU E3-1270 V2 #3.50GHz
RAM: 32GB
System: 64-bit operating system
Thanks
Jonathan
Basically, don't use a thread per socket; use one of the async APIs (BeginReceive / ReceiveAsync), or some kind of socket polling (Socket.Select for example, although note that this is implemented in a very awkward way; when I use this, I actually use P/Invoke to get to the raw underlying API). Right at this moment, I have > 30k sockets per process talking to our web-sockets server (which is implemented via via Socket). Note that for OS reasons we do split that over a few different ports - mainly due to limitations of our load-balancer:
One thread per connection is not a really good idea specially when you have to handle 100s of client concurrently.Asynchronous is the way to go with some buffer pooling/managing. If you are looking for something to start with asynchronous sockets have a look at this basic implementation if you are looking for something complete Take a look at this(explanation: Here)
If you are willing check this out too.
In C# you can go with classical BeginXXX/EndXXX methods. Microsoft also have a High Performance Socket API which can be leveraged using XXXAsync methods. A few articles which explain the High Performance Socket API Here and Here
Im writing a application that reads logs from 1-many computers in the network. The network computers with the logs dont have tcp/ip installed, they are using NetBEUI protocol instead.
So i access them with "\\computername\c$\path-to-logs"
My question is, how can i access them without having to wait for the long network wait if the network is not available? It could be 1 computer with logs...and it could be up to 5
Example:
check \\computer1\c$\path-to-logs ...found it, copy logs
check \\computer2\c$\path-to-logs ...found it, copy logs
check \\computer3\c$\path-to-logs ...didnt find it (here is normally a long wait before i get the timeout that it doesnt exist)
Best regards Andreas
Andreas,
simplest solution is to make it multi-thread, to open a thread per remote PC.
In communication, you always need to pay attention to communication- time - out when one of the PC's is not available. Multi threading with limiting communication time out is the solution I usually using.
When you have a network path open in Windows explorer, and you drag it to a local folder does it open a socket? Also, when you use c# FileStream fin = new FileStream(#"//networkpath/file); does that open a socked? my question is this, would it be just as fast to stream a file over a socket manually as it would be to read it over a network using c#'s filestream?
The Windows file service works over TCP/IP by default (although not necessarily), so typically, there's a socket involved. Yes, there's some overhead from the SMB protocol that Windows uses. However, for files where transfer time matters, the overhead is small compared to the data.
In addition, coming up with your own file sharing protocol without a very good reason is a bad idea. It's a lot of development and debugging work, you have to install the server part somehow, you have to think of security implications (user authentication, etc), firewalls will break it... Just not worth it.
To gauge the amount of work involved, read the description of the FTP protocol.
I have been doing research for a few months now on the possibility of client-server communication. I have experimented with many methods such as WebORB and FluorineFX, which are both servers designed to deal with client/server authentication.
WebORB only runs on Windows for their .NET version as far as I can tell, and I would much rather use an open source system. I have tried using FluorineFX, but I think their must be a simpler way for me to build my own simple system from the ground up.
I have been using Dropbox for a while now, and I like the way that the client-server communication is instant. As far as I can tell (from some Google searches) the client doesn't open a port of its own, and just communicates with the Dropbox server through port 80. An example of its instant communication is where you may delete a file on Dropbox on their website, and instantly the server communicates with the client telling it what has happened. I don't know how this instant communication is possible without opening a port.
I can create a system that uses fetching from the client, asking the server every 10 seconds or so to see if there are any updates, but I would like a method to be able to push the information from the server to the client.
My server runs Linux so I don't think I can use WCF, and ideally I am looking for a way to make PHP and C# communicate with each other.
I would love to hear any advice that anyone has and how they deal with the problem.
Cheers.
You CAN use WCF to communicate with any platform. Just make sure you're using an endpoint which your target machine support: http://msdn.microsoft.com/en-us/library/ms733107.aspx
Have you tried the good old .NET Remoting which runs perfectly with Mono?
You can choose between a TcpChannel (for performance) and a HttpChannel (to pass proxy/firewall easily).
For push notifications, you can open a connection to your server and wait for an answer indefinitely.
I am about to develop a Network measurement tool. The objective is to make a tool, which can measure the responsetime in between a client and a server machine (from the client side). It is s side-application to a main application - If the main applicaiton experiences that the responsetime from the server is above a certain threshold, the tool will be kicked alive, and performs network connectivity tests, to determine of the client server connection is stable (it might be unstable, due to the network being wireless etc.)
The tests I need to perform are not just ping operations, but also transmitting packages of different size.
I have however very little experience in communications technology.
Is ICMP protocol the way to go? and if yes, is it possible to send packages of differnet sizes (to measure if the network is able to transfer eg. 2 MB of data in a reasonable time)?
I have a second concern. What should I look out for in regards to firewalls? It would be a shame to develop an application which works fine on my local network, but as soon as it is used out in the real life, it fails misserably because the tests are blocked by a firewall.
I hope my questions aren't too noobish, but know that any help is much appreciated.
All the best
/Sagi
To keep clear of firewalls, you should do a test using the same protocol and port you use, and create inside of your application a new type of message that should be responded as soon as it is read by the server: You should program your ping measures.
Then the client would measure the times spent in travel traveled and compute your ping and relay it back to your server. This also gives a better reading when in case of some ISPs that give a ICMP protocol packets a huge advantage over other packages on their QoS server, artificially creating(faking) lower latency. And also, you would not have to worry about the firewall not allowing your ICMP packets, because you would have to be allowed to conect on the standart port you use.
Also, most games work this way (Half-Life, Age Of Empires etc.) , and not by sending standard Ping packets.