I have a client server application. My server is in PHP, Mysql and Apache and client is developed using C# windows Form. I have SOAP WSDL webservice for client server communication.
Recently I found a problem, when my client sends the request, response comes after very long time (like 3/4 mins to some hrs.), and sometimes I never gets response. I have checked all the timeout value in client (httpwebrequest timeout, readwritetimeout) as well as server(timeout, keepalivetimeout) side, the max value I have is 5mins (for httpwebrequest readwritetimeout). So can anybody tell what would be the problem? Why it is taking hours to get response or not geting any response?
In my experience, problems like these come with the web-service connection being blocked by a firewall, or a wonky proxy in the way. Check that this is not the issue.
You should first begin be locating the problem by narrowing down the options. Have you tried calling the web service on the server locally, see if you get the same problem - if you don't then it is with high likeliness certainly a connection problem.
To also rule out the client having problems, try using something like http://www.soapui.org/ instead to call your server web service.
Where are you calling the server from? Are you sure the device you call it from is not being IP-blocked, and are you sure your web service is able to access its database from where it is being run.
Does the MySQL user defined for your server API to use have access from the IP of the server. MySQL users are often blocked by IP as well.
If you're running it all locally, are you sure your IIS Express settings/virtual folders are not jumbled up and the URLs are resolving wrong. Try creating the virtual folder again to rule out this. Even when running locally, remember to check that the MySQL user has access from your local IP.
Here's a few things I usually check when I have issues like yours.
Related
I'm working with a project which combines angular app on a client-side and .net core 6 web API app on the server-side. To provide real-time communication between client and server on different browsers without reloading the page I use SignalR (with custom hubs of course) to track connections' Ids and send data to specific clients by connections' Ids which is stored in SQL server database after client connection and removed after client disconnection. On my local environment all works fine, but after deployment on hosting a websocket problem happened. On the first screenshot u can see no errors in my browser console in a couple of minutes after client connection and some data manipulations between client and server through hubs. On the second screenshot u can see the result of this data-manipulations between client and server but on the remote hosting server. I'm so confused about it, because this error happened only on remote server, locally websocket transfer type works as it expected.
Is it a hosting server error which needs to be resolved by hosting provider? Or this is my mistake?
I think there is a lot of questions with the same subject on the stack overflow, but I was searching for the right answer which can be a good solution for my problem, but... I can't find anything which can help me. Feel free to ask more info about signalR implementation if it needs to help me in this situation. Thanks!
I'm accessing Dynamics 365 Business Central OData API in C# application, and when accessing data in my local system is good and when we deployed the application to client server, randomly (50%) they are getting the error "The server committed a protocol violation. Section=ResponseStatusLine".
I have checked the article https://techcommunity.microsoft.com/t5/iis-support-blog/protocol-violation-section-responsestatusline/ba-p/1227792 and applied all the 3 suggestions, but none of them worked.
I'm able to access the client Business Central API integration application in my local system without any issues.
Assuming that this is client Firewall or load balancer issue. But not able to find the solution.
There are many case behind this issue, avoiding the problem rather than actually fixing it. One of the most common cause of this error is the corrupt or missing headers in the request.
Solution:
The server responds with a 100 continue in an incorrect way. Setting expect 100 continue to false and reducing the socket idle time to two seconds
HttpRequestObj.ServicePoint.Expect100Continue = false;
HttpRequestObj.ServicePoint.MaxServicePointIdleTime = 2000;
Ignore corrupted/missing headers. Ref: Link
Stop skype if it is running on the machine.
If a webserver uses UTF-8 that outputs the byte-order-marker (BOM). For example, the default constant Encoding.UTF8 outputs the BOM, and it is easy to forget this. The webpages will work correctly in Firefox and Chrome but HttpWebRequest will bomb. A quick fix is to change the webserver to use the UTF-8 encoding that doesn't output the BOM.
Check the end point of your request server. ex:https or http.
First of all, my apologies for the most likely inappropriate wording of the question. Not knowing exactly how to describe the problem I need to solve has been a major roadblock in my attempts to solve it.
I currently have a web server (Laravel) that needs to communicate with a SQL server in a different network, which only permits outgoing traffic. I made it work by having a C# daemon, running inside the SQL server's network, poll it for data and send it to the server through HTTP POST requests.
However, I now need the web server to communicate with the daemon. Something as simple as:
someone looks up a username on the web server
the server requests the daemon to look it up on the database
the daemon returns whatever information it found to the web server.
What I'm struggling with is finding the best way to do this.
All I need is for the server to be able to push requests to the daemon in real time. The daemon can reply through HTTP POST requests to the server, just like it is doing already. The best potential solution I have found is WebSockets, but it also sound like it might be overkill.
Am I missing something or are WebSockets indeed the way to go?
Guzzle is what I use to make HTTP requests to external APIs in Laravel.
Websockets are mostly used when the user has no control over the responses, for example, a chat window. But if you need to, for example, click a button and wait for the response Guzzle is enough.
I am planning a SaaS system, to be written in C#, ASP.NET using WCF that has two separate components:
On a static IP web server in the cloud will be a web app, common to all clients.
Inside each client's office will be another app, installed on a server with IIS.
The site app will obviously be able to connect to the web services published on the web site. But here's the rub - I also want the web app to be able to initiate a connection to the site app... and the on-site server may not necessarily have a static IP. I can't control this, because we may have hundreds of clients at some point in the future, and we cannot limit our saleability by insisting that the customer has a server with fixed IP.
So, how to do this?
I could have the site apps "checking in" with the web every minute or so, to give the web app the possibility of responding with a "while you're here, please do x,y,z..." but that seems very inelegant. Also, if we're talking about hundreds of clients, I don't want to be bombarding my web server with all these "hi there!" messages if they're not actually required.
Is there a better way?
WCF? Here we go:
Use a message based approach (exchange message, no stateful method calls).
Clients connect to the server. Establish a HTTP-based TWO WAY CONNECTION. This way the server can call back to connected clients. This is standard WCF stuff and works well through NAT with version 4 of the .NET framework.
Voila. In case of a disconnect the client can re-connect, re-identify himself and gets the pending messages.
IIRC "push communication" is done by letting the client do a HTTP Request with an indefinate timeout. Then the server responds when he has something to say. After the respons the client immediately makes a new request.
It works out the same way like the server is making the connection and takes far less resources than polling.
Dynamic DNS is one possibility, but depends on your clients/customers.
If the site app is created by you, it only has to contact the web server when its address has changed (or when the site server/web app is restarted). Still, a keep-alive heart beat of, say, every 30 min. to 1 hour isn't a bad idea.
Edit: I think SNMP services may provide the answer but I'm not a networking expert. You'll have to do some digging or ask a separate question on stackoverflow.
What would you say about Comet technology?
Sounds like you'll definitely need some sort of registry on the server, then it could attempt to call out to the client apps if it needs work doing.
Generally it is client apps that check in with the server every X seconds - this is how Selenium grid works anyway. With a central hub with which clients register. When the hub receives a request to run some tests it passes the jobs out to the clients to perform.
You may not need the "checking in". The server could just attempt to call out to a registered client app until it finds one that is available.This way only the server would need a static address (could use a DNS name instead of an IP to make it more robust).
Also have a look at XMPP PubSub. This could be a more robust and standardised way to handle this.
In the end I decided to go with NetTcpBinding, for reasons best given by #Allon Guralnek here. It's worth clicking through and reading what he has to say...
I have a project where I have created web service proxy classes with wsdl.exe and then simply create an instance of that class (inherits System.Web.Services.Protocols.SoapHttpClientProtocol) and call the method that should send a SOAP message. I'm using Visual Studio 2008 if that matters. And I'm trying this in my development machine without access to actual web service that is located inside of customer's intranet. So, the sending will of course not succeed and I will not get any response back but all I would like to see is the exact content of SOAP messages this solution creates and tries to send. How do I see that?
Use fiddler.
Have a look at SOAPUI from eviware.com.
Its a free for personal use Java app. Among other things you can
set it up to run as a dummy test server. Just load up hte WSDL
and enter the dummy data.
In test server mode it will log your requests so you can see whats happening
inside the request message.
If you're Web service is accessed by clear text, non-SSL HTTP, you can just use a sniffer, like Wireshark, to see the data coming from and to your application. Wireshark can trace, filter and analyze wire data. I have used it do debug HTTP and other protocols many times, and it's a great tool to do this.
SOAP messages are simply XML data sent using the HTTP POST method. So you can for example install a local web server on your development machine, configure your web service to use some dummy URI on this server, and grab the network traffic with WireShark (AKA ethereal). The big advantage of this method is that it involves no coding.
Alternatively you can use an HTTP echo server that dumps its incoming traffic, like this one (found while googling "http echo server"):
You can intercept the call with tcpMon