I have a similiar situation like this: How do I handle/fix "Error getting response stream (ReadDone2): ReceiveFailure" when using MonoTouch? but I'm only GETing a list, not posting anything in the body.
Furthermore, I'm using RestSharp, and it works in almost all the cases, but every once in a while I receive Error getting response stream (ReadDone2): ReceiveFailure.
What can possibly be the problem?
(ps: the exact same code on Wp7 doesn't cause any errors)
There is a bug report (https://bugzilla.xamarin.com/show_bug.cgi?id=19673) which appears to have a reproducible example. So, at the least, you could add yourself to the CC list for it.
(BTW, I get the error (also using restsharp) under Linux (Mint/17, Mono 3.2.8), so it is not specific to Android. It is hard to reproduce: for me it is simply happening after between 1000 and 10,000 web service calls, and it always works when restarting. I am not seeing a CPU or memory problem. It could be some buffer build-up, or might simply be a network failure, or even remote server problem?)
Related
I am deploying my Nodejs sample app to Google App Engine Flexible env and when I am using google app engine URL which is in the form appspot.com to hit my API, it is taking around 11 secs to send response from my mobile data, but other APIs are sending response in milisecs.
Also, the time delay is only happening when I am opening my android app and sending request to the server after that all requests are taking normal time, and again delay is coming when I again open the app and send request to the server.
Edit - I found that
This can be a caused when your application is still booting up or warming up instances to serve the request and can be called as loading latency. To avoid such scenarios you can implement health check handler like readiness check so that your application will only receive traffic when its ready
That's why I checked in my Logs that readiness check is performed sometimes around 1 sec
and sometimes around 200 ms
Can anyone please tell me is there anything wrong in warming up my instances because I don't think cold boot time is causing this problem.
Edit 2
I have also tried to set min_num_instances: 2 so that once loaded atleast my 2 instances will again not get boot up, but the thing is delay is again same.
Edit 3
runtime: nodejs
#vm: true
env: flex
automatic_scaling:
min_num_instances: 2
max_num_instances: 3
Edit 4
I am noticing a strange behaviour that when I am using this app Packet Capture to capture traffic, then all https requests (if I am not enabling SSL Proxying) and all Http requests are executing in milisecs whereas without using this app all Http/Https requests are taking 11-16 secs of delay.
I don't know how but is there any certificate kind of issue here?
Edit 5
Below I have attached Network Profiler where delay is coming 15 secs
Please Help
Depends on which App Engine you are using and how you setup the scaling, there's always a loading time if you don't have a ready instance to serve a request. But if you have readiness check to ensure your instance is ready (and not cold started for the request), then there shouldn't be a problem.
Can you find a loading request or any corresponding slow request in your logs? If not, then it's likely an issue with the app. If possible, instead of calling this API on your app, do it from two apps (one is already open, one is not). So you make calls from both apps and if you notice that the one that's already open is getting a response faster than the other one, that means that's a problem with the app itself. App Engine can't determine whether or not your app is pre-opened so any difference would be client side.
=== Additional information ===
In the your logs, there's no delay at all. The request enter Google and was processed within a few milliseconds. I am sure there's something application-side. Maybe your app is constructing the request URL (first request) from some other source that results in the delay? App Engine has no knowledge of whether or not your app is opened or not or whether it's sending a first request after being opened, it cannot act differently based on it. As long as your App Engine instance is ready and available, it will treat your request the same way regardless of whether or not it's your first request after the app is opened.
The issue is resolved now, it was happening because of network service provider which is Bharti Airtel, their DNS lookup was taking the time to resolve the hostname. After explicitly using alternative DNS like Google 8.8.8.8 the issue got completely resolved. Maybe it's a compatibility issue of Airtel with Google Cloud.
Last time I checked I remember having to put a warmup request handler so that Google would know that the instance is up and running and can be used to answer calls. Keep in mind that code has to be EXACTLY under the endpoint you specify in the handler under the yaml file. (Wouldn't be the first time someone forgets that)
Here are the docs https://cloud.google.com/appengine/docs/standard/python/configuring-warmup-requests this is python specific, but you can also check other languages like Go, Java, and such in the docs.
If the problem is client dependant (each time a new clients spawns and makes a call it gets the latency) then it is most likely, either a problem with the client app itself or with initialization, registration or DNS resolution.
You could also try to reproduce the requests with CURL or similar, and see if also with those you see the mentioned delay.
We have an android app that uses soap to communicate with an API implemented in C++ with gsoap. The android application uses the ksoap2-android library for soap communications.
When the android app runs on an actual device and communicates over wifi everything seems to work as it should. However when run in the emulater (virtualized x86 image) requests with longer replies often fail with a ProtocolException unexpected end of stream.
This error and because it only tends to happen with long responses let me to the believe that on the gsoap side the socket gets closed to soon. I have tried somethings.
default accept_flags on the gsoap side didn't work
explicitly remove SO_LINGER flags from accept_flags in gsoap, didn't solve the issue (I was worried it might set linger with a timeout of zero which would result in exactly my problem)
explicitly specify the SO_LINGER flag in the accept flags and a timeout of 10, didn't solve the issue
Then i tried adding a sleep for 1 second right before shutdown in gsoaps tcp_disconnect function. That solved the problem but sleeping is no good ofcourse.
As sleeping is not a good solution I ended up using select which seems to work ok but I'm not 100% confident in this solution.
Here is the actual code change. These are the last lines of the tcp_disconnect function in stdsoap2.cpp. The tcp_select call is what I have added.
if (soap_valid_socket(soap->socket) && !(soap->omode & SOAP_IO_UDP))
{
tcp_select(soap, soap->socket, SOAP_TCP_SELECT_RCV | SOAP_TCP_SELECT_ERR, 5);
soap->fshutdownsocket(soap, soap->socket, SOAP_SHUT_RDWR);
soap->fclosesocket(soap, soap->socket);
soap->socket = SOAP_INVALID_SOCKET;
}
return SOAP_OK;
}
Is this the right solution?
I'm seeing this really bizarre issue with okhttp. I am using okhttp to upload files to the server via post streaming. It's the same code as in okhttp recipes for post streaming:
while ((count = source.read(buffer)) != -1) {
sink.write(buffer, 0, count);
}
This works fine. The loop is inside writeTo method, which is part of the RequestBody - all like in the recipe. The body is wrapped into try/catch block and on IOException I fail my upload task and move on. This worked perfectly with okhttp 3.0.1.
I've now updated to okhttp 3.4.1 and I'm getting a really weird and inconsistent behavior. I'm testing with switching on the airplane mode mid upload and expecting to get IOException to fail the upload, but sometimes I'm getting it and sometimes not. I can't really figure out what this behavior is connected with. Just killing the app and repeating the test case will throw the expected exception once every 5 times or so.
Wondering if anyone else has seen similar behaviour and if there are any workaround apart from downgrading back to 3.0.1?
EDIT:
It looks like there are several exceptions that are all extending IOExceptions but not all of them make it out of the okhttp land.
These two are never reaching my try/catch block:
java.io.IOException: closed
at okhttp3.internal.framed.Http2$Writer.data(Http2.java:482)
at okhttp3.internal.framed.FramedConnection.writeData(FramedConnection.java:332)
at okhttp3.internal.framed.FramedStream$FramedDataSink.emitDataFrame(FramedStream.java:516)
at okhttp3.internal.framed.FramedStream$FramedDataSink.write(FramedStream.java:489)
at okio.RealBufferedSink.emitCompleteSegments(RealBufferedSink.java:176)
at okio.RealBufferedSink.write(RealBufferedSink.java:96)
at okio.RealBufferedSink.write(RealBufferedSink.java:96)
javax.net.ssl.SSLException: Write error: ssl=0x9bad4480: I/O error during system call, Connection timed out
at com.android.org.conscrypt.NativeCrypto.SSL_write(Native Method)
at com.android.org.conscrypt.OpenSSLSocketImpl$SSLOutputStream.write(OpenSSLSocketImpl.java:771)
at okio.Okio$1.write(Okio.java:78)
at okio.AsyncTimeout$1.write(AsyncTimeout.java:180)
at okio.RealBufferedSink.emitCompleteSegments(RealBufferedSink.java:171)
at okio.RealBufferedSink.write(RealBufferedSink.java:41)
at okhttp3.internal.framed.Http2$Writer.dataFrame(Http2.java:494)
at okhttp3.internal.framed.Http2$Writer.data(Http2.java:487)
at okhttp3.internal.framed.FramedConnection.writeData(FramedConnection.java:311)
at okhttp3.internal.framed.FramedStream$FramedDataSink.emitDataFrame(FramedStream.java:515)
at okhttp3.internal.framed.FramedStream$FramedDataSink.write(FramedStream.java:488)
at okio.RealBufferedSink.emitCompleteSegments(RealBufferedSink.java:171)
at okio.RealBufferedSink.write(RealBufferedSink.java:91)
However, this one seems to be getting all the way to my try/catch block:
okhttp3.internal.framed.StreamResetException: stream was reset: CANCEL
at okhttp3.internal.framed.FramedStream.checkOutNotClosed(FramedStream.java:574)
at okhttp3.internal.framed.FramedStream.access$1200(FramedStream.java:34)
at okhttp3.internal.framed.FramedStream$FramedDataSink.emitDataFrame(FramedStream.java:508)
at okhttp3.internal.framed.FramedStream$FramedDataSink.write(FramedStream.java:488)
at okio.RealBufferedSink.emitCompleteSegments(RealBufferedSink.java:171)
at okio.RealBufferedSink.write(RealBufferedSink.java:91)
I have a feeling this might be something to do with my okhttp client being set to retryOnConnectionFailure(true), but if that is the case, why a total loss of connectivity (airplane mode) is considered a recoverable failure?
EDIT 2:
Did some testing with retryOnConnectionFailure(false) and all of the above exceptions are now making it to my try/catch block. Also added an interceptor (network) and set retryOnConnectionFailure(true), repeated the test and noticed that okhttp goes into an endless loop of sending out requests to my server. Bug or a feature and I'm not using it correctly? Really confused with this behaviour..
My Android app uses the AWS Java SDK for uploading user photos to S3.
Whenever a user's phone's clock is 'skewed', this causes all transfers to fail. This is a well documented aspect of S3:
http://aws.amazon.com/articles/1109?_encoding=UTF8&jiveRedirect=1#04
It appears that the upstream S3 service reports this error quite clearly:
HTTP Status Code: 403 Forbidden
Error Code: RequestTimeToo-Skewed
Description: The difference between the request time and the server's
time is too large.
However when using the Java SDK, it seems as if the informative 403 code is lost ... and I have only an opaque "TransferState.Failed" to go by (which incidentally is the same error if internet connectivity is lost, if it times out, etc...).
As far as I can tell from the docs:
http://docs.aws.amazon.com/AWSJavaSDK/latest/javadoc/index.html
http://docs.aws.amazon.com/AWSJavaSDK/latest/javadoc/com/amazonaws/services/s3/transfer/TransferProgress.html
http://docs.aws.amazon.com/AWSJavaSDK/latest/javadoc/com/amazonaws/services/s3/transfer/Transfer.TransferState.html
http://docs.aws.amazon.com/AWSJavaSDK/latest/javadoc/com/amazonaws/services/s3/transfer/Upload.html
There is no way to get the additional "RequestTimeToo-Skewed" metadata about a transfer failure.
Am I missing it? Is there any way to get additional error information when an S3 transfer fails using Amazon's Java SDK?
UPDATE #1:
A commenter kindly highlighted that I should clarity two points:
I am actually using the AWS SDK for Android (which seems very similar to the Java SDK, but is nonetheless distinct)
I am using the TransferManager class to perform my upload. Apparently, this is a high-level class that wraps the lower-level AmazonS3Client ... and this lower-level class should expose the error reporting I need, but I am still investigating the exact tradeoffs involved between TransferManager and AmazonS3Client. As far as I can tell, there is no way to get progress information via the (synchronous) AmazonS3Client.putObjectRequest which would be a blocker for me...
UPDATE #2:
My sincere thanks to Jason (of the AWS SDK team) for stopping by and helping me out here. The important information is, indeed, available as properties on an AmazonS3Exception if you use certain methods. The docs had originally confused me and I thought that a manual Thread.sleep() loop was required to poll status (and thus I could not leverage waitForCompletion or waitForException), but if you use ProgressListener on PutObjectRequest you can get full progress callbacks and the error-fidelity of AmazonS3Exception.
these two methods should help you out:
Transfer.waitForCompletion()
Transfer.waitForException()
If you detect that your transfer has failed based on a transfer progress event, you can simply call Transfer.waitForException() to be returned the exception that occurred. That exception will be an AmazonServiceException in this case, with all of the info that you need to see that the real problem was a clock skew issue.
Alternatively, the Transfer.waitForCompletion() method will unwrap the original exception from an ExecutionException and directly throw the original exception, just as if it'd all been happening on one thread. This might be a more convenient approach if you want to use a catch blocks to catch different types of errors cleanly and elegantly.
I disagree that the "catch Exception" block is "brutally broad". The point of that code is to catch any error that happens, mark the transfer as failed and rethrow the error so that the application code can know about it. If it were less broad, then that's exactly the case where exceptions could sneak through and transfer progress wouldn't be updated correctly and would be out of sync with reality.
Give those two methods and shot and let us know if that helps!
Well, I have debugged Amazon's SDK and I'm sorry to say that this information is being swallowed internally. Perhaps I will try to submit a patch.
Details: an AmazonS3Exception is being thrown internally which does in fact accurately report this exact error scenario, but a brutally broad try catch ( Exception e ) consumes it and washes away the specificity.
Here is the guilty try-catch:
https://github.com/aws/aws-sdk-java/blob/master/src/main/java/com/amazonaws/services/s3/transfer/internal/UploadMonitor.java#L145
Here is a screenshot showing that an AmazonS3Exception is correctly thrown with the right info...
My android app keeps logging this warning :
IdleConnectionHandler removing a connection that never existed
What does that mean? Is that a big problem? What should I do to avoid this?
My app makes many http connections in AsyncTask, is that related?
EDIT:
I found that this call was the reason of this message :
httpclient.getConnectionManager().closeIdleConnections(30, TimeUnit.SECONDS);
So maybe it tries to close some connections that don't exist?
It sounds like there is a logic error in your code. You may be able to track down the problems using this Android tool called ARO. You can find out more about it here http://developer.att.com/developer/legalAgreementPage.jsp?passedItemId=9700312
It will help you to understand more about how your application is using the network and how you can improve that part of your application to make it more efficient.
Is there a reason you need to make many http connections at once?
I got that error too, but my app uses internet only for ad loading. Currently I have no permission that my app can use internet, so that is why it says "Removing a connection that never existed". That may be one of the reason for this warning.