I am using Grails Ws-Client Plugin
but my application waits for the SOAP response back from the server from which i am consuming web service and my application waits from this code
def proxy = webService.getClient(wsdlUrl)
This mostly occours when the server is down or net connection is slow.
the wait also continues in case the webservice is temporarily removed from the server and the url containing the wsdl is redirecting to home page of website when try to access on web browser.
How can i detect that the wsdl is present or not and how can i set timeout like property so that the wait for response exist for 10 seconds and then it stops waiting for response and code start executing normally in case of stall .
I also don't get any exception or error as well.
Sounds like there's no read and/or connect timeouts set on the client by default. This should help if the web service is down: proxy.setConnectionTimeout(value_in_milliseconds)
I'm not sure about setting the read timeout though, which is what you'd see if the host was up and accepting connections but the web service wasn't available or not responding. The best solution we found for this was to use the Apache Commons HTTP client instead of the default client, which gave us much more granular configuration over the client's connection settings. It's possible they're in the WS-Client plugin also, but the relevant documentation (actually the GroovyWS documentation) doesn't appear to mention anything about read timeouts.
Related
We are attempting to deploy a SignalR site on a Citrix NetScaler, as opposed to the current deployment on a single server. There are three servers in the farm. If you navigate to any single server, SignalR comes up fine. If you go to the NetScaler address, you get this:
WebSocket connection to
'wss://mysite.com/myapp/signalr/connect?transport=webSockets&clientProtocol=1.5&connectionToken=(token_displayed_here)'
failed: Error during WebSocket handshake: net::ERR_CONNECTION_RESET
After this error, there is about a 10-15 second delay, then it starts working. If I attempt to disable websockets as I have read that Netscalers still have issues with them, the error goes away but the delay remains. I believe the delay is caused by it trying to connect with ServerSentEvents and failing that as well. It appears that only long polling may be working over the NetScaler.
We have checked the NetScaler websocket settings, made sure the servers have the correct machine keys, had a backplane set up (tried Redis and an Oracle Nuget package as that's our typical DB), checked the OWIN versions and web.config settings, all of the stuff that Google told me to do that I could find but still get this error and delay. One thing that I did find is that Netscalers have issues with wss, but haven't been able to find anything about how to account for this. Most of the information found was for people using other load balancing technology.
Is using SignalR (or more specifically, WebSockets or ServerSentEvents) with a NetScaler even doable, and if so what could be causing this problem?
Am working with wso2esb4.9.0 and having around 160 services which are http and are processed frequently, Initially when the server is started every thing is fine all service request response is up to the mark,
After 10-12 days the ESB server gets hanged does not process any request and no exception are seen in the log file even,They are some request which may be piled up in the server and not allowing new connection to process.
when i do restart of the server all the connections get releases and works for other 10-12 days again.
But doing a restart of the server may not be a good idea to do , where can i find these connections and close them if possible and am i missing any config changes of wso2 esb.
Am trying to find some different connection number using JMX and also what to know if any one face this issue and found the possible solution.
I'm using Electron, which is based on Chromium, to create an offline desktop application.
The application uses a remote site, and we are using a service worker to offline parts of the site. Everything is working great, except for a certain situation that I call the "airplane wifi situation".
Using Charles, I have restricted download bandwidth to 100bytes/s. The connection is sent through webview.loadURL which eventually calls LoadURLWithParams in Chromium. The problem is that it does not fail and then activate the service worker, like no connection at all would. Once the request is sent, it waits forever for the response.
My question is, how do I timeout the request after a certain amount of time and load everything from the service worker as if the user was truly offline?
An alternative to writing this yourself is to use the sw-toolbox library, which provides routing and runtime caching strategies for service workers, along with some built in options for helping with these sorts of advanced use cases. In particular, you'd want to use the networkTimeoutSeconds parameter to configure the amount of time to wait for a response from the network before you fall back to a previously cached response.
You can use it like the following:
toolbox.router.get(
new RegExp('my-api\\.com'),
toolbox.networkFirst, {
networkTimeoutSeconds: 10
}
);
That would configure a route that matched GET requests with URLs containing my-api.com, and applied a network-first strategy that will automatically fall back to the previously cached response after 10 seconds.
I am trying to build a java application to scrape a website using HTMLUnit. After extracting some data the application encounters following exception -
java.lang.RuntimeException: org.apache.http.conn.HttpHostConnectException: Connection to siteURL refused.
If I run application again, it is able to extract some data again before failing with the same exception. Probably the server see lot of requests from same client IP and refuses connection for a request.
Also, when application encounters this problem, I am able to connect to the site using a browser.
How can I overcome this problem? In web scraping applications how are such problems approached and resolved?
This is how I debug such issues :
Download Fiddler
By default, fiddler listens on port 8888, all you have to do, is configure webClient to use fiddler as proxy & then all requests being sent can be seen (analyzed, modified & re-sent too) in fiddler.
client.getOptions().setProxyConfig(new ProxyConfig("127.0.0.1", 8888));
From what I can say from my previous experience is that the target site blocks after some-time, you can try adding a pause or rotating proxies & user-agents. You can also try clearing cookies.
Situation: Two web servers, and a browser client. The client has an open websockets connection with Server A. Server A decides that this client should really be serviced by Server B.
I would like to know if there is any established technique for performing this hand-over?
It would be great if this could happen as invisibly as possible for my client side code - but I haven't come across any feature which would allow this.
Best I have come up with so far is Server A sending a 'you should really deal with Server X' message, client closing the WS session and then sending some http request which will get routed to the correct server, and upgraded to WS. I can see the presense of load balancers making this complicatied though.
Any thoughts?
From a programming point of view, the socket connection is treated as an open file handle, and that's what you are trying to pass along. For that, I would check out the question "Portable way to pass file descriptor between different processes" for a handful of methods.
But if you are not writing your own web server, and are looking for an off-the-shelf method for Apache, etc, this probably won't help you much.