I've tried to setup the following configuration with SQL Server and SignalR
http://www.asp.net/signalr/overview/performance/scaleout-with-sql-server
Everything seems to be setup correctly, if I profile SQL server I can see SignalR making calls to the DB, but when I call the hub to send a message to all the clients connected, the message is never sent to the connected browsers.
any idea what could be the problem?
Thank you #smnbss, you just saved my life with your comment inside your question. Just to make it clear for everyone in the future with the same problem, here is the wrong implementation: I was getting the context only once like:
public class SyncService : ISyncService
{
private IHubContext StatusChangeHub { get; set; }
public GatewaySyncService()
{
StatusChangeHub = GlobalHost.ConnectionManager.GetHubContext<Hub>();
}
public void SyncStatusChange(Status newStatus)
{
StatusChangeHub.Clients.All.onStatusChange(newStatus);
}
}
But somehow this only work while not using a backplane. And the correct implementation: you need to get the context everytime you want to send a message:
public class SyncService : ISyncService
{
public void SyncStatusChange(Status newStatus)
{
var context = GlobalHost.ConnectionManager.GetHubContext<Hub>();
context.Clients.All.onStatusChange(newStatus);
}
}
Related
I am working on a Spring project. I want to use scheduler in it and want to schedule it on a variable date. This date has to be taken from database. Is it possible to fetch data from database before server is getting started?
Two solutions come to my mind:
#PostConstruct annotated method of some #Component:
#Component
public class MyBean
{
#PostConstruct
public void init()
{
// Blocking DB call could go here
}
}
Application Events. For the ApplicationReadyEvent:
#Component
public class ApplicationReadyEventListener implements ApplicationListener<ApplicationReadyEvent>
{
#Override
public void onApplicationEvent(ApplicationReadyEvent event)
{
// DB call could go here
//
// Notice that if this is a web services application, it
// would potentially be serving requests while this method
// is being executed
}
}
How do I display the UI of the braintree in codename one? I only have this code `
Purchase.startOrder(new Purchase.Callback() {
public String fetchToken() {
}
public void onPurchaseSuccess(String nonce) {
}
public void onPurchaseFail(String errorMessage) {
}
public void onPurchaseCancel() {
}
});`
pls, I need a guide here. thanks
The call to startOrder will show the UI implicitly on the device once you implement the server side functionality that returns the token.
To test this in a mockup go to the braintree getting started guide you will notice code that looks like this:
public void onBraintreeSubmit(View v) {
DropInRequest dropInRequest = new DropInRequest()
.clientToken("long-token-string-that-looks-like-gibberish");
startActivityForResult(dropInRequest.getIntent(this), REQUEST_CODE);
}
You can use that token for debugging some of the process. Notice that price etc. are all determined in the server to prevent tampering so the token includes all of that data. I'd place the debug token here but I'm not sure if this is something that expires/changes.
I want to send data from WCF to my desktop application while executing a service method.
The WCF service is hosted in windows service.
For example: In my service I am counting from 1 to 100 and when I am hitting 10,20,30 etc I want to set that value on my textbox.
This may be done using duplex channels services:
http://msdn.microsoft.com/en-us/library/ms731064.aspx
Be careful however : this will not work if the server can't reach the client : for example if you are behind a proxy.
I've simpy passed that with get/set like below: (Maybe someone will search smthing similar in future)
public class CallbackHandler : WCFService.IWCFServiceCallback
{
public ListBox LtBox { get; set; }
public void Message(string result)
{
LtBox.Items.Add(result);
}
}
InstanceContext instanceContext = new InstanceContext(new CallbackHandler() { LtBox=this.ltBox });
Where ltBox is my Listbox in desktop application.
Thanks all for help.
I tried to solve by myself, but... Looks like I need help from people.
I have Business Silverlight application with WCF RIA and EntityFramework. Access to Database I get via LinqToEntites.
Common loading data from database I making by this:
return DbContext.Customers
This code returns full Customers table from DataBase. But sometimes I do not need to show all data. Easy way is use linq filters in client side by next code:
public LoadInfo()
{
...
var LO1 = PublicDomainContext.Load(PublicDomainContext.GetCustomersQuery());
LO1.Completed += LO1Completed;
...
}
private void LO1Completed(object sender, EventArgs eventArgs)
{
...
DatatViewGrid.ItemsSource = null;
DatatViewGrid.ItemsSource = loadOperation.Entities.Where(c=>c ...filtering...);
//or PublicDomainContext.Customers.Where(c=>c ...filtering...)
...
}
However this way has very and very important flaw: all data passing from server to client side via DomainService may be viewed by applications like Fiddler. So I need to come up with another way.
Task: filter recieving data in server side and return this data.
Way #1: LinqToEntites has a beautiful projection method:
//MSDN Example
var query =
contacts.SelectMany(
contact => orders.Where(order =>
(contact.ContactID == order.Contact.ContactID)
&& order.TotalDue < totalDue)
.Select(order => new
{
ContactID = contact.ContactID,
LastName = contact.LastName,
FirstName = contact.FirstName,
OrderID = order.SalesOrderID,
Total = order.TotalDue
}));
But, unfortunately, DomainServices cannot return undefined types, so this way won't work.
Way #2: I found next solution - make separate DTO classes (DataTransferObject). I just read some samples and made on the server side next class:
[DataContract]
public partial class CustomerDTO
{
[DataMember]
public int ISN { get; set; }
[DataMember]
public string FIO { get; set; }
[DataMember]
public string Listeners { get; set; }
}
And based this class I made a row of methods which return filtered data:
[OperationContract]
public List<CustomerDTO> Customers_Common()
{
return DbContext.Customers....Select(c => new CustomerDTO { ISN = c.ISN, FIO = c.FIO, Listeners = c.Listeners }).ToList();
}
And this works fine, all good...
But, there is strange problem: running application locally does not affect any troubles, but after publishing project on the Web Site, DomainService returns per each method HTTP 500 Error ("Not Found" exception). Of course, I cannot even LogIn into my application. DomainService is dead. If I delete last class and new methods from application and republish - all works fine, but without speacial filtering...
The Question: what I do wrong, why Service is dying with new classes, or tell me another way to solve my trouble. Please.
U P D A T E :
Hey, finally I solved this!
There is an answer: Dynamic query with WCF RIA Services
Your best shot is to find out what is causing the error. For that, override the OnError method on the DomainService like this:
protected override void OnError(DomainServiceErrorInfo errorInfo)
{
/* Log the error info to a file. Don't forget inner exceptions.
*/
base.OnError(errorInfo);
}
This is useful, because only two exceptions will be passed to the client, so if there are a lot of nested inner exceptions, you should still be able to see what actually causes the error.
In addition, you can inspect the error by attaching the debugger to the browser instance you are opening the site with. In VS2010 this is done by doing [Debug] -> [Attach to Process] in the menu-bar.
Using the pub/sub sample i managed to get multiple instances of the same console app to read all messages sent from the publisher. What I did whas this:
namespace Subscriber1
{
public class EndpointConfig : IConfigureThisEndpoint, AsA_Server
{
}
public class OverrideInputQueue : IWantCustomInitialization
{
public void Init()
{
Configure
.Instance
.Configurer
.ConfigureComponent<MsmqTransport>(NServiceBus.ObjectBuilder.ComponentCallModelEnum.None)
.ConfigureProperty(p => p.InputQueue, Guid.NewGuid());
}
}
}
How do i setup a wpf app to have multiple instances all read notifications from the publisher??
Using the code above doesn't do it for me because those lines of code will never be hit.
In my wpf app i reference the NServiceBus host, I add this to the windows code behind:
public Window1()
{
InitializeComponent();
this.Title = App.AppId.ToString();
var bus = NServiceBus.Configure.With()
.DefaultBuilder()
.XmlSerializer()
.MsmqTransport()
.IsTransactional(true)
.PurgeOnStartup(false)
.UnicastBus()
.ImpersonateSender(false)
.LoadMessageHandlers()
.CreateBus()
.Start();
}
and I put the I "OverrideInputQueue : IWantCustomInitialization"-part in my endpoint config.
But as I said that part never gets hit. The result is that when you start up two instances of the app, they take turns in picking up the message sent from the publisher. I want both instances to receive ALL messages.
What have I missed?
/Johan
The problem is that IWantCustomInitialization is only relevant when using the NServiceBus.Host.exe process. What you need to do in your initialization code is this:
var bus = NServiceBus.Configure.With()
.DefaultBuilder()
.XmlSerializer()
.MsmqTransport()
.IsTransactional(true)
.PurgeOnStartup(false)
.RunCustomAction( () => Configure.Instance.Configurer.ConfigureProperty<MsmqTransport>(p => p.InputQueue, Guid.NewGuid()) )
.UnicastBus()
.ImpersonateSender(false)
.LoadMessageHandlers()
.CreateBus()
.Start();