I have been having this issue with the NetworkManager which hangs/stuck forever after few request repeatedly (Url with different parameter still). Mostly it works till the 4th request then on the 5th request it hangs.
Please see the code
ConnectionRequest r = new ConnectionRequest();
r.setUrl(url);
r.setPost(false);
r.setDuplicateSupported(true);
NetworkManager.getInstance().addToQueueAndWait(r); // hangs right here
Reader reader = new InputStreamReader(new ByteArrayInputStream(r.getResponseData()), "UTF-8");
I have read few others had the same issue and I did add setDuplicateSupported(true) still getting the same error.
Any help is really appreciated. I really thank for Shai (from codename one) for being very supportive.
Thanks,
addToQueueAndWait literally waits until the network request finishes and in this case it doesn't finish or timeout. You can set a timeout to a lower value to make this fail more gracefully. I suggest reviewing the request you are making and why it is failing.
I also suggest looking at the network monitor to see what is going on.
Related
I am a newbie in CANOPEN. I wrote a program that read actual position via PDO1 (default is statusword + actual position).
void canopen_init() {
// code1 setup PDO mapping
nmtPreOperation();
disablePDO(PDO_TX1_CONFIG_COMM);
setTransmissionTypePDO(PDO_TX1_CONFIG_COMM, 1);
setInhibitTimePDO(PDO_TX1_CONFIG_COMM, 0);
setEventTimePDO(PDO_TX1_CONFIG_COMM, 0);
enablePDO(PDO_TX1_CONFIG_COMM);
setCyclePeriod(1000);
setSyncWindow(100);
//code 2: enable OPeration
readyToSwitchOn();
switchOn();
enableOperation();
motionStart();
// code 3
nmtActiveNode();
}
int main (void) {
canopen_init();
while {
delay_ms(1);
send_sync();
}
}
If I remove "code 2" (the servo is in Switch_on_disable status), i can read position each time sync send. But if i use "code 2", the driver has error "sync frame timeout". I dont know driver has problem or my code has problem. Does my code has problem? thank you!
I don't know what protocol stack this is or how it works, but these:
setCyclePeriod(1000);
setSyncWindow(100);
likely correspond to these OD entries :
Object 1006h: Communication cycle period (CiA 301 7.5.2.6)
Object 1007h: Synchronous window length (CiA 301 7.5.2.7)
They set the SYNC interval and time window for synchronous PDOs respectively. The latter is described by the standard as:
If the synchronous window length expires all synchronous TPDOs may be discarded and an EMCY message may be transmitted; all synchronous RPDOs may be discarded until the next SYNC message is received. Synchronous RPDO processing is resumed with the next SYNC message.
Now if you set this sync time window to 100us but have a sloppy busy-wait delay delay_ms(1), then that doesn't add up. If you write zero to Object 1007h, you disable the sync window feature. I suppose setSyncWindow(0); might do that. You can try to do that to see if that's the issue. If so, you have to drop your busy-wait in favour for proper hardware timers, one for the SYNC period and one for PDO timeout (if you must use that feature).
Problem fixed. Due to much EMI from servo, that make my controller didn't work properly. After isolating, it worked very well :)!
I have MQTT route like below
from("paho:mytopic?brokerUrl=tcp://0.0.0.0:1883&clientId=ipc)
.routeId("myroute")
.to("log:my?showAll=true&multiline=true");
it starts only if broker is available and after that if it lost connectivity with broker it handle it very well and resume.
But my concern is how i can start first time if broker is not available?
I searched on google and got to know "SupervisingRouteController" might help in this regard, But no document is available how i can use it.
By some hit and trial i reach this point but what further i can do as no document available
final Main main = new Main();
main.addRouteBuilder(new MyMqttRoute());
SupervisingRouteController controller = main.getCamelContexts().get(0).getRouteController().unwrap(SupervisingRouteController.class);
main.run();
Here are two unit test cases that shows usage of SupervisingRouteController.
SupervisingRouteControllerTest.java
SupervisingRouteControllerRestartTest.java
These may be helpful in understanding its usage.
I'm trying to implement a very simple service connected to an AMQP broker with Alpakka. I just want it to consume messages from its queue as a stream at the moment they are pushed on a given exchange/topic.
Everything seemed to work fine in my tests, but when I tried to start my service, I realized that my stream was only consuming my messages once and then exited.
Basically I'm using the code from Alpakka documentation :
def consume()={
val amqpSource = AmqpSource.committableSource(
TemporaryQueueSourceSettings(connectionProvider, exchangeName)
.withDeclaration(exchangeDeclaration)
.withRoutingKey(topic),
bufferSize = prefetchCount
)
val amqpSink = AmqpSink.replyTo(AmqpReplyToSinkSettings(connectionProvider))
amqpSource.mapAsync(4)(msg => onMessage(msg)).runWith(amqpSink)
}
I tried to schedule the consume() execution every second, but I experienced OutOfMemoryException issues.
Is there any proper way to make this code run as an infinite loop ?
If you want to have a Source restarted when it fails or is cancelled, wrap it with RestartSource.withBackoff.
In SL4 application I perform a lot of requests (30) to the server in the same time (+~3 sec) by using HttpWebRequest. As a result I receive the same count of responses and start to process streams
HttpWebRequest request = (HttpWebRequest) asynchronousResult.AsyncState;
HttpWebResponse response = (HttpWebResponse) request.EndGetResponse(asynchronousResult)
using (var stream = new StreamReader(response.GetResponseStream()))
{
var str = stream.ReadToEnd();
var doc = XDocument.Parse(str);
}
All responsies are received (server returned 304 - not modified)
For each response program creates new thread (because of asynchronusResult).
When I try to fetch data from stream it takes a lot of time when stream.ReadToEnd() method works. I don't now what inside ReadToEnd() but it seems that stream reading performs in one thread or any locking occurs. Any ideas??
Why it happes? Everything incapsulated in separate threads and works fast except this method.
Presumably you are using the browser http stack, in which case your browser will almost certainly have a limit on the number of connections you can make to a given subdomain at once- in many browser this is two.
A common trick, is to use multiple sub domains to serve content.
Sporadically, I receive an error in my WP7 Silverlight application. The error is a random "System.NotSupportedException". This error is thrown occassionally when the following code is executed:
// 1. Build the url
string serviceURL = "http://www.mydomain.com/service.svc/param1/param2";
// 2. Asynchronously execute the query using HttpWebRequest instead of WebClient. There is a UI performance issue with the WebClient currently
WebRequest request = HttpWebRequest.Create(serviceUrl);
request.BeginGetResponse(new AsyncCallback(MyService_Completed), request);
...
private void MyService_Completed(IAsyncResult result)
{
// Do stuff
}
I have verified that the URL I am sending is correct. Please note, that this request is part of my view model, which may have other network requests fired off at the same time. I have no idea why this happens ocassionally. Can anybody point out any potential reasons?
Thank you!
When this happens, make sure you look at the View Detail part of the exception report. It might be that your service is refusing connection or the data passed is invalid. NotSupported is a very general exception that covers many possible situations.
A similar question has been asked previously. If you look at the comments the original poster added to the answer, he claims to have solved the problem by replacing
request.BeginGetResponse(new AsyncCallback(MyService_Completed), request);
with
request.BeginGetResponse( MyService_Completed, request);