I'm playing around with AWS Translate a bit. I want AWS Translate to auto-detect the source language, when I send a TranslateTextAsync request. Apparently, there can be a DetectedLanguageLowConfidenceException, which I want to handle by getting the DetectedLanguageCode from the exception and retry the translation. I was not able to get this exception to occur, so I don't know the structure of that response exception.
For the Java SDK, I found that there is a "getDetectedLanguageCode" function, but this one doesn't exist in the .NET SDK. I'm using AWSSDK.Translate v3.3.101.12.
How do I get the language code from the DetectedLanguageLowConfidenceException?
I contacted AWS Support and they reached out to their AWS Translate team. They write that
C#/.Net does not support member variables in exceptions the way Java does. However, supplementary information about exceptions is stored in the Data dictionary of the exception
They also mention that AWS Translate will usually use even a low confidence guess before throwing a DetectedLanguageLowConfidenceException, so it seems like we don't really have to worry about it.
I still went and implemented the exception handling and have the following code to extract the detected language code data. This code is untested though:
catch (DetectedLanguageLowConfidenceException ex)
{
var dictionary = ex.Data as Dictionary<object, object>;
var detectedLanguageCode = dictionary?["DetectedLanguageCode"] as string;
// Retry here with the detected low confidence language code.
}
Related
I'm currently developing a simple application for querying/retrieving data on a PACS. I use DCMTK for this purpose, and a DCM4CHEE PACS as test server.
My goal is to implement simple C-FIND queries, and a C-MOVE retrieving system (coupled with a custom SCP to actually download the data).
To do so, I've created a CustomSCU class, that inherits the DCMTK DcmSCU class.
I first implemented a C-ECHO message, that worked great.
Then, I tried to implement C-FIND requesting, but I got the error "DIMSE No valid Presentation Context ID" (more on that in the next paragraph) from my application, but no other log from DCM4CHEE. I've then used the command tool findscu (from dcmtk) to see if there was some configuration issue but the tool just worked fine. So in order to implement my C-FIND request, I've read the source of findscu (here) and adapted it in my code (meaning that i'm not using DcmSCU::sendCFindRequest but the class DcmFindSU).
But now, i'm facing the same problem with C-MOVE request. My code is pretty straight-forward :
//transfer syntaxes
OFList<OFString> ts;
ts.push_back(UID_LittleEndianExplicitTransferSyntax);
ts.push_back(UID_BigEndianExplicitTransferSyntax);
ts.push_back(UID_LittleEndianImplicitTransferSyntax);
//sop class
OFString pc = UID_MOVEPatientRootQueryRetrieveInformationModel;
addPresentationContext(pc, ts);
DcmDataset query;
query.putAndInsertOFStringArray(DCM_QueryRetrieveLevel, "PATIENT");
query.putAndInsertOFStringArray(DCM_PatientID, <ThePatientId>);
OFCondition condition = sendMOVERequest(findPresentationContextID(pc, ""), getAETitle(), &query, nullptr);
return condition.good();
I've also tried using UID_MOVEStudyRootQueryRetrieveInformationModel instead of UID_MOVEPatientRootQueryRetrieveInformationModel, with the same result : my application shows the error
DIMSE No valid Presentation Context ID
As I understand, a presentation context is concatenation of one or more transfer syntax and one SOP class. I read that the problem could come from the PACS that won't accept my presentation contexts. To be sure, I used the movescu tool (from DCMTK). It worked, and I saw this in the logs from de server DCM4CHEE :
received AAssociatedRQ
pc-1 : as=<numbers>/Patient Root Q/R InfoModel = FIND
ts=<numbers>/Explicit VR Little Endian
ts=<numbers>/Explicit VR Big Endian
ts=<numbers>/Implicit VR Little Endian
That means that the movescu tool does a find before attempting an actual move ?
Therefore, I changed my application context creation with :
OFList<OFString> ts;
ts.push_back(UID_LittleEndianExplicitTransferSyntax);
ts.push_back(UID_BigEndianExplicitTransferSyntax);
ts.push_back(UID_LittleEndianImplicitTransferSyntax);
OFString pc1 = UID_FINDPatientRootQueryRetrieveInformationModel;
OFString pc = UID_MOVEPatientRootQueryRetrieveInformationModel;
addPresentationContext(pc1, ts);
addPresentationContext(pc, ts);
(also tried study root)
But this didn't do the trick.
The problem seems to lie on the client side, as findPresentationContextID(pc, ""); alwasy return 0, no matter what.
I don't feel like it's possible to adapt the code of the movescu tool, as it appears to be very complex and not adequat for simple retrieve operations.
I don't know what to try. I hope someone can help me understand what's going on. That's the last part of my application, as the storage SCP already works.
Regards
It looks like you are not negotiating the association with the PACS.
After adding the presentation contexts and before sending any command, the SCU must connect to the PACS and negotiate the PresentationContexts with DcmSCU::initNetwork and then DcmSCU::negotiateAssociation.
When I run dataflow jobs that writes to google cloud datastore, sometime I see the metrics show that I had one or two datastoreRpcErrors:
Since these datastore writes usually contain a batch of keys, I am wondering in the situation of RpcError, if some retry will happen automatically. If not, what would be a good way to handle these cases?
tl;dr: By default datastoreRpcErrors will use 5 retries automatically.
I dig into the code of datastoreio in beam python sdk. It looks like the final entity mutations are flushed in batch via DatastoreWriteFn().
# Flush the current batch of mutations to Cloud Datastore.
_, latency_ms = helper.write_mutations(
self._datastore, self._project, self._mutations,
self._throttler, self._update_rpc_stats,
throttle_delay=_Mutate._WRITE_BATCH_TARGET_LATENCY_MS/1000)
The RPCError is caught by this block of code in write_mutations in the helper; and there is a decorator #retry.with_exponential_backoff for commit method; and the default number of retry is set to 5; retry_on_rpc_error defines the concrete RPCError and SocketError reasons to trigger retry.
for mutation in mutations:
commit_request.mutations.add().CopyFrom(mutation)
#retry.with_exponential_backoff(num_retries=5,
retry_filter=retry_on_rpc_error)
def commit(request):
# Client-side throttling.
while throttler.throttle_request(time.time()*1000):
try:
response = datastore.commit(request)
...
except (RPCError, SocketError):
if rpc_stats_callback:
rpc_stats_callback(errors=1)
raise
...
I think you should first of all determine which kind of error occurred in order to see what are your options.
However, in the official Datastore documentation, there is a list of all the possible errors and their error codes . Fortunately, they come with recommended actions for each.
My advice is that your implement their recommendations and see for alternatives if they are not effective for you
For uninteresting reasons, I have to use jRuby on a particular project where we also want to use Amazon Simple Workflow (SWF). I don't have a choice in the jRuby department, so please don't say "use MRI".
The first problem I ran into is that jRuby doesn't support forking and SWF activity workers love to fork. After hacking through the SWF ruby libraries, I was able to figure out how to attach a logger and also figure out how to prevent forking, which was tremendously helpful:
AWS::Flow::ActivityWorker.new(
swf.client, domain,"my_tasklist", MyActivities
) do |options|
options.logger= Logger.new("logs/swf_logger.log")
options.use_forking = false
end
This prevented forking, but now I'm hitting more exceptions deep in the SWF source code having to do with Fibers and the context not existing:
Error in the poller, exception:
AWS::Flow::Core::NoContextException: AWS::Flow::Core::NoContextException stacktrace:
"aws-flow-2.4.0/lib/aws/flow/implementation.rb:38:in 'task'",
"aws-flow-2.4.0/lib/aws/decider/task_poller.rb:292:in 'respond_activity_task_failed'",
"aws-flow-2.4.0/lib/aws/decider/task_poller.rb:204:in 'respond_activity_task_failed_with_retry'",
"aws-flow-2.4.0/lib/aws/decider/task_poller.rb:335:in 'process_single_task'",
"aws-flow-2.4.0/lib/aws/decider/task_poller.rb:388:in 'poll_and_process_single_task'",
"aws-flow-2.4.0/lib/aws/decider/worker.rb:447:in 'run_once'",
"aws-flow-2.4.0/lib/aws/decider/worker.rb:419:in 'start'",
"org/jruby/RubyKernel.java:1501:in `loop'",
"aws-flow-2.4.0/lib/aws/decider/worker.rb:417:in 'start'",
"/Users/trcull/dev/etl/flow/etl_runner.rb:28:in 'start_workers'"
This is the SWF code at that line:
# #param [Future] future
# Unused; defaults to **nil**.
#
# #param block
# The block of code to be executed when the task is run.
#
# #raise [NoContextException]
# If the current fiber does not respond to `Fiber.__context__`.
#
# #return [Future]
# The tasks result, which is a {Future}.
#
def task(future = nil, &block)
fiber = ::Fiber.current
raise NoContextException unless fiber.respond_to? :__context__
context = fiber.__context__
t = Task.new(nil, &block)
task_context = TaskContext.new(:parent => context.get_closest_containing_scope, :task => t)
context << t
t.result
end
I fear this is another flavor of the same forking problem and also fear that I'm facing a long road of slogging through SWF source code and working around problems until I finally hit a wall I can't work around.
So, my question is, has anyone actually gotten jRuby and SWF to work together? If so, is there a list of steps and workarounds somewhere I can be pointed to? Googling for "SWF and jRuby" hasn't turned up anything so far and I'm already 1 1/2 days into this task.
I think the issue might be that aws-flow-ruby doesn't support Ruby 2.0. I found this PDF dated Jan 22, 2015.
1.2.1
Tested Ruby Runtimes The AWS Flow Framework for Ruby has been tested
with the official Ruby 1.9 runtime, also known as YARV. Other versions
of the Ruby runtime may work, but are unsupported.
I have a partial answer to my own question. The answer to "Can SWF be made to work on jRuby" is "Yes...ish."
I was, indeed, able to get a workflow working end-to-end (and even make calls to a database via JDBC, the original reason I had to do this). So, that's the "yes" part of the answer. Yes, SWF can be made to work on jRuby.
Here's the "ish" part of the answer.
The stack trace I posted above is the result of SWF trying to raise an ActivityTaskFailedException due to a problem in some of my activity code. That part is my fault. What's not my fault is that the superclass of ActivityTaskFailedException has this code in it:
def initialize(reason = "Something went wrong in Flow",
details = "But this indicates that it got corrupted getting out")
super(reason)
#reason = reason
#details = details
details = details.message if details.is_a? Exception
self.set_backtrace(details)
end
When your activity throws an exception, the "details" variable you see above is filled with a String. MRI is perfectly happy to take a String as an argument to set_backtrace(), but jRuby is not, and jRuby throws an exception saying that "details" must be an Array of Strings. This exception blows through all the nice error catching logic of the SWF library and into this code that's trying to do incompatible things with the Fiber library. That code then throws a follow-on exception and kills the activity worker thread entirely.
So, you can run SWF on jRuby as long as your activity and workflow code never, ever throws exceptions because otherwise those exceptions will kill your worker threads (which is not the intended behavior of SWF workers). What they are designed to do instead is communicate the exception back to SWF in a nice, trackable, recoverable fashion. But, the SWF code that does the communicating back to SWF has, itself, code that's incompatible with jRuby.
To get past this problem, I monkey-patched AWS::Flow::FlowException like so:
def initialize(reason = "Something went wrong in Flow",
details = "But this indicates that it got corrupted getting out")
super(reason)
#reason = reason
#details = details
details = details.message if details.is_a? Exception
details = [details] if details.is_a? String
self.set_backtrace(details)
end
Hope that helps someone in the same situation as me.
I'm using JFlow, it lets you start SWF flow activity workers with JRuby.
I am working on a blackberry application. I need to call soap webservices, but I am unable to do so, and am getting null as a response. Following is my code:
private static final String CONNECTION_PARAMS = ";deviceside=true";
SoapObject request = new SoapObject("http://service.action.com/",
"findActiveSecurities");
SoapSerializationEnvelope envelope = new SoapSerializationEnvelope(SoapEnvelope.VER11);
envelope.bodyOut = request;
HttpTransportBasicAuth ht =
new HttpTransportBasicAuth("http://myurl.com/ebclient/services/MobileClientService?wsdl"+CONNECTION_PARAMS,
"myusername",
"mypassword");
PropertyInfo propInfo=new PropertyInfo();
propInfo.type=PropertyInfo.INTEGER_CLASS;
//adding parameters
request.addProperty("arg0","NSE");
request.addProperty("arg1","0");
request.addProperty("arg2","100");
envelope.setOutputSoapObject(request);
try {
ht.call(SOAP_ACTION, envelope);
result = (SoapObject)envelope.getResponse();
System.out.println(result);
} catch (IOException e) {
e.printStackTrace();
} catch (XmlPullParserException e) {
e.printStackTrace();
}
I am getting null as a result.Please have a look at the code and help me to correct it.
Thanks in advance
Actually the problem was instead of passing 0 and 100 as String ...
request.addProperty("arg0","NSE");
request.addProperty("arg1","0");
request.addProperty("arg2","100");
I use
request.addProperty("arg0","NSE");
request.addProperty("arg1",new Integer(0));
request.addProperty("arg2",new Integer(1000));
also this link helped me.
also before asking this question I was facing some problem that the Simulator was not recognizing a Library. It shows error message something like "there is no library Ksoap2_j2me.jar" - resolved from this link.
Sorry for poor English but I think this can save time of some other developer.
It's hard to tell from what you're posted, but my guess is that you're having some kind of network problem. I'm guessing that you initialize result = null;, and then your call to ht.call() throws an IOException, leaving result null.
You're using ksoap2, which is a library written for generic J2ME clients. However, BlackBerry networking doesn't work exactly like all other J2ME platforms.
You are controlling the BlackBerry network transport with your connection params string, which is hardcoded:
private static final String CONNECTION_PARAMS = ";deviceside=true";
Unfortunately, this string suffix may not be right for all network conditions (or any, if you don't have device APN settings correct).
I think you have a couple choices:
1. Connection Suffix Strings
You can try dynamically choosing the right suffix string, depending on conditions when your app runs. This can allow the device, for example, to connect via Wi-Fi if it's available, or via BES if that's available. Developers new to BlackBerry may be surprised that app code needs to worry about this (read here for more, or watch this).
If you want to simply replace CONNECTION_PARAMS with a dynamic string, you might check out the implementation here.
2. ConnectionFactory
In OS 5.0, BlackBerry added the ConnectionFactory class, which was a big improvement over the old way of having to assemble connection strings. If you only need to support OS 5.0 and greater, you might choose to rewrite the code to use ConnectionFactory.
Since you have access to the ksoap source code, you could change it. It looks like the connection code is in ServiceConnectionMidp.java:
public ServiceConnectionMidp(String url) throws IOException {
connection = (HttpConnection) Connector.open(url, Connector.READ_WRITE, true);
}
Instead of attaching connection parameters to the url passed to this class, you could change the class to get the connection from a ConnectionFactory, customized to support the network transports you want.
Doing this means that if you ever want to update your code to use a new version of ksoap2, you'll need to make these modifications again. However, given the future of BlackBerry Java, that seems like a reasonable compromise to make.
I need to design a SOAP api (my first one!). What are the best practices regarding errors returned to the caller.
Assuming an api as follow
[WebMethod]
public List<someClass> GetList(String param1)
{
}
Should I
Throw an exception. Let the SOAP infrastructure generate a SOAP fault -- and the caller would have to try/catch. This is not very explanatory to the caller
Have the return parameter be a XMLDOcument of some sort, with the first element being a return value and then the List.
Looking at the return SOAP packet I see that the response generated looks like the following
<GetListResponse>
<GetListResult>
...
...
</GetListResult>
</GetListResponse>
Can we somehow change the return packet so that the "GetListResult" element is changed to "GetListError" in case of error
Any other way?
Thanks!
Probably the most appropriate SOA pattern to follow would be a Fault Contract, which is essentially a Data Contract that is wrapped in the SOAPException.
I am posting examples in .NET, since it looks like that is what you are using (and that is what I know :) )
In WCF, you can define a DataContract, then decorate your OperationContract interface with a a "FaultContract" attribute that specifies it as the return value:
public partial interface MyServiceContract
{
[System.ServiceModel.FaultContract(typeof(MyService.FaultContracts.ErrorMessageFaultContract))]
[System.ServiceModel.OperationContract(...)]
ResponseMessage SOAMethod(RequestMessage request) {...}
}
For ASMX web services, (as it appears you are using from your code snippet), you can't use this attribute or setup. So to implement the pattern, you would need to:
Define a serializable class to hold your exception information (i.e. ErrorData)
When an exception is thrown in your service, catch it and in your error handling code, add the info to the ErrorData class
Append the serialized ErrorData class to a SoapException class:
SoapException mySoapException = new SoapException(message, SoapException.ServerFaultCode, "", serialzedErrorDataClass);
Throw the SoapException in your code
On your client side, you will need to deserialize the message to interpret it.
Kind of seems like a lot of work, but this way you have total control of what data gets returned. Incidentally, this is the pattern that is used by the ServiceFactory from Microsoft patterns & practices for ASMX web services.
There is some good information on Coding Horror.
You can cause the correct fault to be returned from old ASMX services, but it's not easy. First of all, you'll have to hand-code the WSDL, because the ASMX infrastructure will never create Fault elements in a WSDL. Then, you have to serialize the desired fault data into an XmlElement that you will then provide as the Detail property of the SoapException that you will throw.
It's much easier with WCF. You can declare a number of FaultContracts for each operation, and WCF will generate the correct WSDL to refer to them. You then simply throw a FaultException, where type T is the type of the FaultContract. Pass the T instance to the constructor, and you're all set.
I can't give you specifies for .net (which seems to be what you're asking), but SOAP provides a mechanism for expressing strongly-typed exceptions. The SOAP fault element can have an optional FaultDetail sub-element, and this can contain arbitrary XML documents, such as your GetListError. These document types should be defined in the WSDL as a wsdl:fault inside the wsdl:operation
The trick is persuading the web service stack to turn an exception (which is the "correct" way of writing your business logic) into a properly marshalled fault detail. And I can't help you with that bit.