I'm currently using Hangfire in an ASP.NET MVC 5 project, which uses Ninject to use the same Context in RequestScope.
In Hangfire dashboard, I get random errors like:
System.Data.Entity.Core.EntityException: An error occurred while starting a transaction on the provider connection. See the inner exception for details. ---> System.Data.SqlClient.SqlException: New transaction is not allowed because there are other threads running in the session.
How can I make Entity, ASP.NET and Hangfire work without getting all those transaction errors?
I bet those errors can happen on the other side (in web).
We also encountered some issues like this with Hangfire along side Ninject. So we actually create a separate kernel for Hangfire, where everything is bound in thread scope. Something like this:
public class NinjectHangfire
{
public static IKernel CreateKernelForHangfire()
{
var kernel = new StandardKernel(/*modules*/);
try
{
kernel.Bind<Func<IKernel>>().ToMethod(ctx => () => new Bootstrapper().Kernel).InThreadScope();
kernel.Bind<IHttpModule>().To<HttpApplicationInitializationHttpModule>().InThreadScope();
//other bindings
}
catch
{
kernel.Dispose();
throw;
}
}
}
And then in Startup:
GlobalConfiguration.Configuration.UseNinjectActivator(NinjectHangfire.CreateKernelForHangfire());
Related
I’m having issues running realm with xUnite and Net core. Here is a very simple test that I want to run
public class UnitTest1
{
[Scenario]
public void Test1()
{
var realm = Realm.GetInstance(new InMemoryConfiguration("Test123"));
realm.Write(() =>
{
realm.Add(new Product());
});
var test = realm.All<Product>().First();
realm.Write(() => realm.RemoveAll());
}
}
I get different exceptions on different machines (Windows & Mac) on line where I try to create a Realm instace with InMemoryConfiguration.
On Mac I get the following exception
libc++abi.dylib: terminating with uncaught exception of type realm::IncorrectThreadException: Realm accessed from incorrect thread.
On Windows I get the following exception when running
ERROR Unable to read data from the transport connection: An existing connection was forcibly closed by the remote host. at
System.Net.Sockets.NetworkStream.Read(Span1 destination) at
System.Net.Sockets.NetworkStream.ReadByte() at
System.IO.BinaryReader.ReadByte() at
System.IO.BinaryReader.Read7BitEncodedInt() at
System.IO.BinaryReader.ReadString() at
Microsoft.VisualStudio.TestPlatform.CommunicationUtilities.LengthPrefixCommunicationChannel.NotifyDataAvailable() at
Microsoft.VisualStudio.TestPlatform.CommunicationUtilities.TcpClientExtensions.MessageLoopAsync(TcpClient client, ICommunicationChannel channel, Action1 errorHandler, CancellationToken cancellationToken) Source: System.Net.Sockets HResult: -2146232800 Inner Exception: An existing connection was forcibly closed by the remote host HResult: -2147467259
I’m using Realm 3.3.0 and xUnit 2.4.1
I’ve tried downgrading to Realm 2.2.0, and it didn’t work either.
The solution to this problem was found in this Github post
The piece of code from that helped me to solve the issue
Realm GetInstanceWithoutCapturingContext(RealmConfiguration config)
{
var context = SynchronizationContext.Current;
SynchronizationContext.SetSynchronizationContext(null);
Realm realm = null;
try
{
realm = Realm.GetInstance(config);
}
finally
{
SynchronizationContext.SetSynchronizationContext(context);
}
return realm;
}
Though it took a while for me to apply this to my solution.
First and foremost, instead of just setting the context to null I am using Nito.AsyncEx.AsyncContext. Because otherwise automatic changes will not be propagated through threads, as realm needs a non-null SynchronizationContext for that feature to work. So, in my case the method looks something like this
public class MockRealmFactory : IRealmFactory
{
private readonly SynchronizationContext _synchronizationContext;
private readonly string _defaultDatabaseId;
public MockRealmFactory()
{
_synchronizationContext = new AsyncContext().SynchronizationContext;
_defaultDatabaseId = Guid.NewGuid().ToString();
}
public Realm GetRealmWithPath(string realmDbPath)
{
var context = SynchronizationContext.Current;
SynchronizationContext.SetSynchronizationContext(_synchronizationContext);
Realm realm;
try
{
realm = Realm.GetInstance(new InMemoryConfiguration(realmDbPath));
}
finally
{
SynchronizationContext.SetSynchronizationContext(context);
}
return realm;
}
}
Further, this fixed a lot of failing unit tests. But I was still receiving that same exception - Realm accessed from incorrect thread. And I had no clue why, cause everything was set correctly. Then I found that the tests that were failing were related to methods where I was using async realm api, in particular realm.WriteAsync. After some more digging I found the following lines in the realm documentation.
It is not a problem if you have set SynchronisationContext.Current but
it will cause WriteAsync to dispatch again on the thread pool, which
may create another worker thread. So, if you are using Current in your
threads, consider calling just Write instead of WriteAsync.
In my code there was no direct need of using the async API. I removed and replaced with sync Write and all the tests became green again! I guess if I find myself in a situation that I do need to use the async API because of some kind of bulk insertions, I'd either mock that specific API, or replace with my own background thread using Task.Run instead of using Realm's version.
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.
I recently started porting our .Net 4.6 web application to .Net Core 2.0 and am having some problems regarding the access to System.DirectoryServices.AccountManagement
I want to access GroupPrincipal.getMembers() but keep getting an UnsafeNativeMethods exception:
System.DirectoryServices.Interop.UnsafeNativeMethods+IAds.GetInfoEx(object vProperties, int lnReserved)
System.DirectoryServices.DirectoryEntry.RefreshCache(String[] propertyNames)
System.DirectoryServices.AccountManagement.RangeRetriever.GetNextChunk()
System.DirectoryServices.AccountManagement.RangeRetriever.MoveNext()
System.DirectoryServices.AccountManagement.ADDNLinkedAttrSet.GetNextEnum()
System.DirectoryServices.AccountManagement.ADDNLinkedAttrSet.MoveNextMemberEnum()
System.DirectoryServices.AccountManagement.ADDNLinkedAttrSet.MoveNext()
System.DirectoryServices.AccountManagement.FindResultEnumerator.MoveNext()
AspNetCore._Views_Groups_Show_cshtml+<ExecuteAsync>d__0.MoveNext() in Show.cshtml
+
#foreach (var p in Model.GetMembers())
System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
The code in the Show.cshtml:
#using System.DirectoryServices.AccountManagement
#model GroupPrincipal
#foreach (var p in Model.GetMembers())
{
...
}
The exception:
System.Exception: An operations error occurred.
Already tried moving the code from the view into the controller and marking it with unsafe but that doesn't help either.
Code is already running as domain admin, can access all users etc. Just the method calls don't work.
What's the correct way to handle this?
Ok, seems that I've found a solution/workaround:
I saw that it processes the principals and throws an exception after processing them.
So I just put the principals in another list and caught the exception.
The new list contains all principals and can be accessed without problems.
List<Principal> members = new List<Principal>();
try
{
members.AddRange(group.GetMembers());
}
catch (Exception)
{
; // do nothing
}
Must be a bug in the .NET core implementation of System.DirectoryServices.AccountManagement
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());
}
});
}