I have the gRPC server code as below:
public void buildServer() {
List<BindableService> theServiceList = new ArrayList<BindableService>();
theServiceList.add(new CreateModuleContentService());
theServiceList.add(new RemoveModuleContentService());
ServerBuilder<?> sb = ServerBuilder.forPort(m_port);
for (BindableService aService : theServiceList) {
sb.addService(aService);
}
m_server = sb.build();
}
and client code as below:
public class JavaMainClass {
public static void main(String[] args) {
CreateModuleService createModuleService = new CreateModuleService();
ESDStandardResponse esdReponse = createModuleService.createAtomicBlock("8601934885970354030", "atm1");
RemoveModuleService moduleService = new RemoveModuleService();
moduleService.removeAtomicBlock("8601934885970354030", esdReponse.getId());
}
}
While I am running the client I am getting an exception as below:
Exception in thread "main" io.grpc.StatusRuntimeException: UNIMPLEMENTED: Method grpc.blocks.operations.ModuleContentServices/createAtomicBlock is unimplemented
at io.grpc.stub.ClientCalls.toStatusRuntimeException(ClientCalls.java:233)
at io.grpc.stub.ClientCalls.getUnchecked(ClientCalls.java:214)
at io.grpc.stub.ClientCalls.blockingUnaryCall(ClientCalls.java:139)
In the above server class, if I am commenting the line theServiceList.add(new RemoveModuleContentService()); then the CreateModuleContentService service is working fine, also without commenting all the services of RemoveModuleContentService class are working as expected, which means the problem is with the first service when another gets added.
Can someone please suggest how can I add two services to Server Builder.
A particular gRPC service can only be implemented once per server. Since the name of the gRPC service in the error message is ModuleContentServices, I'm assuming CreateModuleContentService and RemoveModuleContentService both extend ModuleContentServicesImplBase.
When you add the same service multiple times, the last one wins. The way the generated code works, every method of a service is registered even if you don't implement that particular method. Every service method defaults to a handler that simply returns "UNIMPLEMENTED: Method X is unimplemented". createAtomicBlock isn't implemented in RemoveModuleContentService, so it returns that error.
If you interact with the ServerServiceDefinition returned by bindService(), you can mix-and-match methods a bit more, but this is a more advanced API and is intended more for frameworks to use because it can become verbose to compose every application service individually.
Related
I've got two hosted services in my web service: Domain and ComplianceService. ComplianceService needs to reference data and methods in Domain, like so:
public ComplianceService(ILogger<ComplianceService> logger, Domain domain, IRuleRepository ruleRepository)
{
// Initialize the service.
this.logger = logger;
this.domain = domain;
this.ruleRepository = ruleRepository;
}
My initialization in startup.cs looks like this:
// Add the dependencies.
serviceCollection.AddSingleton<RulesActivator>()
.AddSingleton<Accruals>()
.AddSingleton<IRuleRepository, ComplianceRuleRepository>()
.AddSingleton<IViolation, Violation>();
// Add the hosted services.
serviceCollection.AddHostedService<Domain>();
serviceCollection.AddHostedService<ComplianceService>();
When I try to run this, I get this message:
System.InvalidOperationException: 'Unable to resolve service for type 'ThetaRex.OpenBook.ServerDomain.Domain' while attempting to activate 'ThetaRex.OpenBook.WebApi.ComplianceService'.'
If I add Domain to the IoC, like this:
serviceCollection.AddSingleton<Domain>()
.AddSingleton<RulesActivator>()
.AddSingleton<Accruals>()
.AddSingleton<IRuleRepository, ComplianceRuleRepository>()
.AddSingleton<IViolation, Violation>();
It runs, but I get two copies of Domain. I can force it to work like this:
// Add the hosted services.
serviceCollection.AddHostedService(sp => sp.GetRequiredService<Domain>());
if (this.Configuration.GetValue<bool>("ComplianceEnabled"))
{
serviceCollection.AddHostedService<ComplianceService>();
}
But this seems really clumsy and counterintuitive. How come the AddHostedService can instantiate ComplianceService, but can't instantiate the dependent service?
So, I'm trying to create a sample where there are the following components/features:
A hangfire server OWIN self-hosted from a Windows Service
SignalR notifications when jobs are completed
Github Project
I can get the tasks queued and performed, but I'm having a hard time sorting out how to then notify the clients (all currently, just until I get it working well) of when the task/job is completed.
My current issue is that I want the SignalR hub to be located in the "core" library SampleCore, but I don't see how to "register it" when starting the webapp SampleWeb. One way I've gotten around that is to create a hub class NotificationHubProxy that inherits the actual hub and that works fine for simple stuff (sending messages from one client to all).
In NotifyTaskComplete, I believe I can get the hub context and then send the message like so:
private void NotifyTaskComplete(int taskId)
{
try
{
var hubContext = GlobalHost.ConnectionManager.GetHubContext<NotificationHub>();
if (hubContext != null)
{
hubContext.Clients.All.sendMessage(string.Format("Task {0} completed.", taskId));
}
}
catch (Exception ex)
{
}
}
BUT, I can't do that if NotificationHubProxy is the class being used as it's part of the SampleWeb library and referencing it from SampleCore would lead to a circular reference.
I know the major issue is the hub in the external assembly, but I can't for the life of me find a relevant sample that's using SignalR or MVC5 or setup in this particular way.
Any ideas?
So, the solution was to do the following two things:
I had to use the SignalR .NET client from the SampleCore assembly to create a HubConnection, to create a HubProxy to "NotificationHub" and use that to Invoke the "SendMessage" method - like so:
private void NotifyTaskComplete(string hostUrl, int taskId)
{
var hubConnection = new HubConnection(hostUrl);
var hub = hubConnection.CreateHubProxy("NotificationHub");
hubConnection.Start().Wait();
hub.Invoke("SendMessage", taskId.ToString()).Wait();
}
BUT, as part of creating that HubConnection - I needed to know the url to the OWIN instance. I decided to pass that a parameter to the task, retrieving it like:
private string GetHostAddress()
{
var request = this.HttpContext.Request;
return string.Format("{0}://{1}", request.Url.Scheme, request.Url.Authority);
}
The solution to having a Hub located in an external assembly is that the assembly needs to be loaded before the SignalR routing is setup, like so:
AppDomain.CurrentDomain.Load(typeof(SampleCore.NotificationHub).Assembly.FullName);
app.MapSignalR();
This solution for this part came from here.
I am currently investigating the possibility of using a Java Web Service (as described by the Info*Engine documentation of Windchill) in order to retrieve information regarding parts. I am using Windchill version 10.1.
I have successfully deployed a web service, which I consume in a .Net application. Calls which do not try to access Windchill information complete successfully. However, when trying to retrieve part information, I get a wt.method.AuthenticationException.
Here is the code that runs within the webService (The web service method simply calls this method)
public static String GetOnePart(String partNumber) throws WTException
{
WTPart part=null;
RemoteMethodServer server = RemoteMethodServer.getDefault();
server.setUserName("theUsername");
server.setPassword("thePassword");
try {
QuerySpec qspec= new QuerySpec(WTPart.class);
qspec.appendWhere(new SearchCondition(WTPart.class,WTPart.NUMBER,SearchCondition.LIKE,partNumber),new int[]{0,1});
// This fails.
QueryResult qr=PersistenceHelper.manager.find((StatementSpec)qspec);
while(qr.hasMoreElements())
{
part=(WTPart) qr.nextElement();
partName = part.getName();
}
} catch (AuthenticationException e) {
// Exception caught here.
partName = e.toString();
}
return partName;
}
This code works in a command line application deployed on the server, but fails with a wt.method.AuthenticationException when performed from within the web service. I feel it fails because the use of RemoteMethodServer is not what I should be doing since the web service is within the MethodServer.
Anyhow, if anyone knows how to do this, it would be awesome.
A bonus question would be how to log from within the web service, and how to configure this logging.
Thank you.
You don't need to authenticate on the server side with this code
RemoteMethodServer server = RemoteMethodServer.getDefault();
server.setUserName("theUsername");
server.setPassword("thePassword");
If you have followed the documentation (windchill help center), your web service should be something annotated with #WebServices and #WebMethod(operationName="getOnePart") and inherit com.ptc.jws.servlet.JaxWsService
Also you have to take care to the policy used during deployment.
The default ant script is configured with
security.policy=userNameAuthSymmetricKeys
So you need to manage it when you consume your ws with .Net.
For logging events, you just need to call the log4j logger instantiated by default with $log.debug("Hello")
You can't pre-authenticate server side.
You can write the auth into your client tho. Not sure what the .Net equivilent is, but this works for Java clients:
private static final String USERNAME = "admin";
private static final String PASSWORD = "password";
static {
java.net.Authenticator.setDefault(new java.net.Authenticator() {
#Override
protected java.net.PasswordAuthentication getPasswordAuthentication() {
return new java.net.PasswordAuthentication(USERNAME, PASSWORD.toCharArray());
}
});
}
long time ASP.Net interface developer being asked to learn WCF, looking for some education on more architecture related fronts - as its not my strong suit but I'm having to deal.
In our current ASMX world we adopted a model of creating ServiceManager static classes for our interaction with web services. We're starting to migrate to WCF, attempting to follow the same model. At first I was dealing with performance problems, but I've tweaked a bit and we're running smoothly now, but I'm questioning my tactics. Here's a simplified version (removed error handling, caching, object manipulation, etc.) of what we're doing:
public static class ContentManager
{
private static StoryManagerClient _clientProxy = null;
const string _contentServiceResourceCode = "StorySvc";
// FOR CACHING
const int _getStoriesTTL = 300;
private static Dictionary<string, GetStoriesCacheItem> _getStoriesCache = new Dictionary<string, GetStoriesCacheItem>();
private static ReaderWriterLockSlim _cacheLockStories = new ReaderWriterLockSlim();
public static Story[] GetStories(string categoryGuid)
{
// OMITTED - if category is cached and not expired, return from cache
// get endpoint address from FinderClient (ResourceManagement SVC)
UrlResource ur = FinderClient.GetUrlResource(_contentServiceResourceCode);
// Get proxy
StoryManagerClient svc = GetStoryServiceClient(ur.Url);
// create request params
GetStoriesRequest request = new GetStoriesRequest{}; // SIMPLIFIED
Manifest manifest = new Manifest{}; // SIMPLIFIED
// execute GetStories at WCF service
try
{
GetStoriesResponse response = svc.GetStories(manifest, request);
}
catch (Exception)
{
if (svc.State == CommunicationState.Faulted)
{
svc.Abort();
}
throw;
}
// OMITTED - do stuff with response, cache if needed
// return....
}
internal static StoryManagerClient GetStoryServiceClient(string endpointAddress)
{
if (_clientProxy == null)
_clientProxy = new StoryManagerClient(GetServiceBinding(_contentServiceResourceCode), new EndpointAddress(endpointAddress));
return _clientProxy;
}
public static Binding GetServiceBinding(string bindingSettingName)
{
// uses Finder service to load a binding object - our alternative to definition in web.config
}
public static void PreloadContentServiceClient()
{
// get finder location
UrlResource ur = FinderClient.GetUrlResource(_contentServiceResourceCode);
// preload proxy
GetStoryServiceClient(ur.Url);
}
}
We're running smoothly now with round-trip calls completing in the 100ms range. Creating the PreloadContentServiceClient() method and adding to our global.asax got that "first call" performance down to that same level. And you might want to know we're using the DataContractSerializer, and the "Add Service Reference" method.
I've done a lot of reading on static classes, singletons, shared data contract assemblies, how to use the ChannelFactory pattern and a whole bunch of other things that I could do to our usage model...admittedly, some of its gone over my head. And, like I said, we seem to be running smoothly. I know I'm not seeing the big picture, though. Can someone tell me what I've ended up here with regards to channel pooling, proxy failures, etc. and why I should head down the ChannelFactory path? My gut says to just do it, but my head can't comprehend why...
Thanks!
ChannelFactory is typically used when you aren't using Add Service Reference - you have the contract via a shared assembly not generated via a WSDL. Add Service Reference uses ClientBase which is essentially creating the WCF channel for you behind the scenes.
When you are dealing with REST-ful services, WebChannelFactory provides a service-client like interface based off the shared assembly contract. You can't use Add Service Reference if your service only supports a REST-ful endpoint binding.
The only difference to you is preference - do you need full access the channel for custom behaviors, bindings, etc. or does Add Service Reference + SOAP supply you with enough of an interface for your needs.
Please considerer the following scenario :
I have created a full-web application by using the ASP .NET MVC 3 framework. Now my application is managed by a web server.
An HTTP request is received on the server-side of my application.
A class implementing the singleton design pattern is instanciated on server-side.
A response is sent to the browser.
Another HTTP request is received on the server-side of my application. Is the singleton instance used at step 2 still available on server-side ?
I read some information about the life cycle of an ASP .NET application on this page : http://msdn.microsoft.com/en-us/library/ms178473.aspx
But I am still not able to answer my question.
Thanks in advance for your future help
I have just made some tests under VS2010.
Here is the list of the main components of my project :
The Home controller containing an Index HttpGet action method.
The view resulting from the Index action method.
The SingletonTest class which implements the singleton design pattern.
Here is the code of the SingletonTest class :
public class SingletonTest
{
private int counter;
private static SingletonTest instance = null;
public int Counter
{
get
{
return counter;
}
}
public static SingletonTest Instance
{
get
{
if (instance == null)
instance = new SingletonTest();
return instance;
}
}
private SingletonTest()
{
counter = 0;
}
public void IncrementCounter()
{
counter++;
}
}
Here is the code of the Index action method :
public ActionResult Index()
{
SingletonTest st = SingletonTest.Instance;
st.IncrementCounter();
return View();
}
Here is the code of the view :
#SingletonTest.Instance.Counter
Here the test scenario I have followed :
The IIS server has been automatically launched by VS2010.
I have requested the /Home/Index/ URL then the value 1 has been displayed.
I have requested the /Home/Index/ URL then the value 2 has been displayed.
...
This test shows that the SingletonTest instance made at Step 1 is available when processing the next requests.
I guess that a memory space is allocated to my web application on the server.
Then I have stopped the IIS server and I have followed my test scenario again.
I have got the same results as before : 1, 2, ....
Even though the singleton may persist across multiple requests you need to be careful for exactly the reasons of your second test - when IIS is restarted or the app pool is recycled everything will be lost.
Are you sure that you need a singleton instance?
If you're looking to persist some state across all requests it would be better to use an external storage such as a database.
What about multi-instances of the same application that IIS Will Create to process the concurrent requests?
I thinks singleton Object will not be the same if IIS Create multiple instances of the same application in high traffic situation