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ZeroMQ Broadcast with Proxy losing messages

I am doing some performance tests on ZeroMQ in order to compare it with others like RabbitMQ and ActiveMQ.
In my broadcast tests and to avoid "The Dynamic Discovery Problem" as referred by ZeroMQ documentation I have used a proxy. In my scenario, I am using 50 concurrent publishers each one sending 500 messages with 1ms delay between sends. Each message is then read by 50 subscribers. And as I said I am losing messages, each of the subscribers should receive a total of 25000 messages and they are each receiving between 5000 and 10000 messages only.
I am using Windows and C# .Net client clrzmq4 (4.1.0.31).
I have already tried some solutions that I found on other posts:
I have set linger to TimeSpan.MaxValue
I have set ReceiveHighWatermark to 0 (as it is presented as infinite, but I have tried also Int32.MaxValue)
I have set checked for slow start receivers, I made receivers start some seconds before publishers
I had to make sure that no garbage collection is made to the socket instances (linger should do it but to make sure)
I have a similar scenario (with similar logic) using NetMQ and it works fine. The other scenario does not use security though and this one does (and that's also the reason why I use clrzmq in this one because I need client authentication with certificates that is not yet possible on NetMQ).
EDIT:
public class MCVEPublisher
{
public void publish(int numberOfMessages)
{
string topic = "TopicA";
ZContext ZContext = ZContext.Create();
ZSocket publisher = new ZSocket(ZContext, ZSocketType.PUB);
//Security
// Create or load certificates
ZCert serverCert = Main.GetOrCreateCert("publisher");
var actor = new ZActor(ZContext, ZAuth.Action, null);
actor.Start();
// send CURVE settings to ZAuth
actor.Frontend.Send(new ZFrame("VERBOSE"));
actor.Frontend.Send(new ZMessage(new List<ZFrame>()
{ new ZFrame("ALLOW"), new ZFrame("127.0.0.1") }));
actor.Frontend.Send(new ZMessage(new List<ZFrame>()
{ new ZFrame("CURVE"), new ZFrame(".curve") }));
publisher.CurvePublicKey = serverCert.PublicKey;
publisher.CurveSecretKey = serverCert.SecretKey;
publisher.CurveServer = true;
publisher.Linger = TimeSpan.MaxValue;
publisher.ReceiveHighWatermark = Int32.MaxValue;
publisher.Connect("tcp://127.0.0.1:5678");
Thread.Sleep(3500);
for (int i = 0; i < numberOfMessages; i++)
{
Thread.Sleep(1);
var update = $"{topic} {"message"}";
using (var updateFrame = new ZFrame(update))
{
publisher.Send(updateFrame);
}
}
//just to make sure it does not end instantly
Thread.Sleep(60000);
//just to make sure publisher is not garbage collected
ulong Affinity = publisher.Affinity;
}
}
public class MCVESubscriber
{
private ZSocket subscriber;
private List<string> prints = new List<string>();
public void read()
{
string topic = "TopicA";
var context = new ZContext();
subscriber = new ZSocket(context, ZSocketType.SUB);
//Security
ZCert serverCert = Main.GetOrCreateCert("xpub");
ZCert clientCert = Main.GetOrCreateCert("subscriber");
subscriber.CurvePublicKey = clientCert.PublicKey;
subscriber.CurveSecretKey = clientCert.SecretKey;
subscriber.CurveServer = true;
subscriber.CurveServerKey = serverCert.PublicKey;
subscriber.Linger = TimeSpan.MaxValue;
subscriber.ReceiveHighWatermark = Int32.MaxValue;
// Connect
subscriber.Connect("tcp://127.0.0.1:1234");
subscriber.Subscribe(topic);
while (true)
{
using (var replyFrame = subscriber.ReceiveFrame())
{
string messageReceived = replyFrame.ReadString();
messageReceived = Convert.ToString(messageReceived.Split(' ')[1]);
prints.Add(messageReceived);
}
}
}
public void PrintMessages()
{
Console.WriteLine("printing " + prints.Count);
}
}
public class Main
{
static void Main(string[] args)
{
broadcast(500, 50, 50, 30000);
}
public static void broadcast(int numberOfMessages, int numberOfPublishers, int numberOfSubscribers, int timeOfRun)
{
new Thread(() =>
{
using (var context = new ZContext())
using (var xsubSocket = new ZSocket(context, ZSocketType.XSUB))
using (var xpubSocket = new ZSocket(context, ZSocketType.XPUB))
{
//Security
ZCert serverCert = GetOrCreateCert("publisher");
ZCert clientCert = GetOrCreateCert("xsub");
xsubSocket.CurvePublicKey = clientCert.PublicKey;
xsubSocket.CurveSecretKey = clientCert.SecretKey;
xsubSocket.CurveServer = true;
xsubSocket.CurveServerKey = serverCert.PublicKey;
xsubSocket.Linger = TimeSpan.MaxValue;
xsubSocket.ReceiveHighWatermark = Int32.MaxValue;
xsubSocket.Bind("tcp://*:5678");
//Security
serverCert = GetOrCreateCert("xpub");
var actor = new ZActor(ZAuth.Action0, null);
actor.Start();
// send CURVE settings to ZAuth
actor.Frontend.Send(new ZFrame("VERBOSE"));
actor.Frontend.Send(new ZMessage(new List<ZFrame>()
{ new ZFrame("ALLOW"), new ZFrame("127.0.0.1") }));
actor.Frontend.Send(new ZMessage(new List<ZFrame>()
{ new ZFrame("CURVE"), new ZFrame(".curve") }));
xpubSocket.CurvePublicKey = serverCert.PublicKey;
xpubSocket.CurveSecretKey = serverCert.SecretKey;
xpubSocket.CurveServer = true;
xpubSocket.Linger = TimeSpan.MaxValue;
xpubSocket.ReceiveHighWatermark = Int32.MaxValue;
xpubSocket.Bind("tcp://*:1234");
using (var subscription = ZFrame.Create(1))
{
subscription.Write(new byte[] { 0x1 }, 0, 1);
xpubSocket.Send(subscription);
}
Console.WriteLine("Intermediary started, and waiting for messages");
// proxy messages between frontend / backend
ZContext.Proxy(xsubSocket, xpubSocket);
Console.WriteLine("end of proxy");
//just to make sure it does not end instantly
Thread.Sleep(60000);
//just to make sure xpubSocket and xsubSocket are not garbage collected
ulong Affinity = xpubSocket.Affinity;
int ReceiveHighWatermark = xsubSocket.ReceiveHighWatermark;
}
}).Start();
Thread.Sleep(5000); //to make sure proxy started
List<MCVESubscriber> Subscribers = new List<MCVESubscriber>();
for (int i = 0; i < numberOfSubscribers; i++)
{
MCVESubscriber ZeroMqSubscriber = new MCVESubscriber();
new Thread(() =>
{
ZeroMqSubscriber.read();
}).Start();
Subscribers.Add(ZeroMqSubscriber);
}
Thread.Sleep(10000);//to make sure all subscribers started
for (int i = 0; i < numberOfPublishers; i++)
{
MCVEPublisher ZeroMqPublisherBroadcast = new MCVEPublisher();
new Thread(() =>
{
ZeroMqPublisherBroadcast.publish(numberOfMessages);
}).Start();
}
Thread.Sleep(timeOfRun);
foreach (MCVESubscriber Subscriber in Subscribers)
{
Subscriber.PrintMessages();
}
}
public static ZCert GetOrCreateCert(string name, string curvpath = ".curve")
{
ZCert cert;
string keyfile = Path.Combine(curvpath, name + ".pub");
if (!File.Exists(keyfile))
{
cert = new ZCert();
Directory.CreateDirectory(curvpath);
cert.SetMeta("name", name);
cert.Save(keyfile);
}
else
{
cert = ZCert.Load(keyfile);
}
return cert;
}
}
This code also produces the expected number of messages when security is disabled, but when turned on it doesn't.
Does someone know another thing to check? Or has it happened to anyone before?
Thanks

Multiple Requests Using Task.WhenAll()

I am trying to stress test my WebApi that is uploaded onto Azure. Specifically this test is for logging into an app. I decided to make a mock client using c# and create a list of Tasks, each of which will send the same request to my WebApi. My problem is that it throws an exception after using more than 300 tasks.
The Exception: "Thread has been Cancelled"
Inner exception: "Object reference not set to an instance of an object."
Code where exception occurs: await (Task.WhenAll(tasks));
Am I doing something wrong in my test code? If so, what? And how to I correct the error? Thanks!
Notes:
-I have tried running the test code against the API locally
-The API code is surrounded by a try catch block and when running the test code against it, it did not hit my breakpoint set in the catch block and an exception was still thrown in the test code.
-Since this is a project at work, I have replaced real log in credentials and the URL to the API with stand-ins
below is my test code
public static async Task<decimal> LoginTestParallel3Async(){
Stopwatch timer = new Stopwatch();
var tasks = new List<Task>();
LoginRequestModel request = new LoginRequestModel();
int numOfRequests = 500;
decimal totalTimeForTasks = 0;
string jsonObject = "";
request.UserName = "User";
request.Password = "Password";
request.UserId = 0;
jsonObject = Newtonsoft.Json.JsonConvert.SerializeObject(request);
try
{
using (var client = new HttpClient())
{
for (int i = 0; i < numOfRequests; i++)
{
//tasks.Add(client.PostAsync("URLForAzure", new StringContent(jsonObject, Encoding.UTF8, "application/json")));
tasks.Add(client.PostAsync("URLForLocal", new StringContent(jsonObject, Encoding.UTF8, "application/json")));
}
timer.Start();
await (Task.WhenAll(tasks));
timer.Stop();
totalTimeForTasks = timer.ElapsedMilliseconds;
Console.WriteLine("total time for request: " + totalTimeForTasks + " milliseconds");
Console.ReadLine();
}
}
catch (Exception e)
{
Console.WriteLine(e.Message.ToString());
return totalTimeForTasks;
}
return totalTimeForTasks;
}

According to the documentation the value of MaxConnectionsPerServer property from HttpClient is 256 by default. So in order to achieve what you need, you have to change this value to a larger number.
https://learn.microsoft.com/en-us/dotnet/api/system.net.http.httpclienthandler.maxconnectionsperserver?view=netcore-2.0#System_Net_Http_HttpClientHandler_MaxConnectionsPerServer
ex.
var client = new HttpClient(new HttpClientHandler { MaxConnectionsPerServer = 1000 });

The requested address is not valid in this context

I have a WCF rest service define like this:
static void Main(string[] args)
{
try
{
DOMConfigurator.Configure();
string serviceUriStr = "http://127.0.0.1:9001/AFMServer";
Uri serviceUri = new Uri(serviceUriStr);
_webHost = new WebServiceHost(typeof(AftermathFacade), serviceUri);
WebHttpBinding binding = new WebHttpBinding(WebHttpSecurityMode.None);
binding.MaxBufferPoolSize = 2000000000;
binding.MaxReceivedMessageSize = 2000000000;
//binding.ReceiveTimeout = TimeSpan.MaxValue;
//binding.CloseTimeout = TimeSpan.MaxValue;
//binding.SendTimeout = TimeSpan.MaxValue;
////binding.OpenTimeout = TimeSpan.MaxValue;
_webHost.AddServiceEndpoint(typeof(IAftermathFacade), binding, serviceUriStr);
ServiceThrottlingBehavior stb = new ServiceThrottlingBehavior();
stb.MaxConcurrentCalls = 1000;
stb.MaxConcurrentInstances = 1000;
stb.MaxConcurrentSessions = 1000;
ServiceMetadataBehavior smb = new ServiceMetadataBehavior();
smb.HttpGetEnabled = true;
_webHost.Description.Behaviors.Add(smb);
_webHost.Description.Behaviors.Add(stb);
_webHost.Open();
_log.Info("Listening on Uri: " + serviceUri.AbsoluteUri);
Console.ReadLine();
}
catch (Exception ex)
{
_log.Error(ex.StackTrace);
}
}
Accessing this service from a client randomly throws a
"The requested address is not valid in this context"
exception. Sometimes it does, sometimes it does not and the remote call works.
What I noticed is that it seems to happen when to calls to the service are made too quickly.
for instance:
CallServiceMethod1();
CallSericeMethod2();
throws an exception.
However:
CallServiceMethod1();
sleep(1000);
CallSericeMethod2();
Works!
Any idea where the problem might be coming from?
Note that the service is hosted on a AWS micro instance (very poor performance). When I test locally on my box, the exception is not happening as often.

How do I implement a C# Thrift service and consume it with a Silverlight client?

I'm current looking at Thrift to use as a RPC framework for our apps (mostly written in C# and Silverlight). I've come as far as implementing a service and consuming it from a C# console app (using a socket as transport).
For the C# server side code my code looked like: (basically copying the tutorials included with the source code)
MyServiceHandler handler = new MyServiceHandler();
MyService.Processor processor = new MyService.Processor(handler);
TServerTransport serverTransport = new TServerSocket(9090);
TServer server = new TSimpleServer(processor, serverTransport);
server.Serve();
For the client side code it looked like:
TTransport transport = new TSocket("localhost", 9090);
TProtocol protocol = new TBinaryProtocol(transport);
MyService.Client client = new MyService.Client(protocol);
transport.Open();
client.SomeServiceCall();
However, we will be consuming the service from a Silverlight client, and unfortunately there is no support for sockets in Silverlight for Thrift. I assume I'm forced to use HTTP communication between the client and service, using Thrift's C# THttpClient and THttpHandler classes? I could not find any examples of how to do this out there, can anyone point me in the right direction? Some example server and client side code would be appreciated.

It seems that this issue was already addressed by this guy. According to this JIRA, the fix is available in Thrift 0.9. You can either try this snapshot (note that, as it's not a final release, it might not be stable) or you can apply this patch to the 0.8 release.

I believe by now you would have understood, there is no direct way of communicating from Silverlight to the Cassandra database either using Thrift or any other clients.
I have one simple option related to this. Write a Silverlight enabled web service and consume it from the client.
For example, on the server side you can have a web service which does insert/update/read etc., like this. I just managed to pull out some code which we use for our project. Hope this helps.
using Apache.Cassandra;
using Thrift.Protocol;
using Thrift.Transport;
namespace CassandraWebLibrary
{
public class MyDb
{
String _host;
int _port;
String _keyspace;
bool _isConnected;
TTransport _transport = null;
Apache.Cassandra.Cassandra.Client _client = null;
String columnFamily = "ColumnFamilyName";
public VazhikaattiDB(String host, int port, String keyspace)
{
_host = host;
_port = port;
_keyspace = keyspace;
_isConnected = false;
}
public bool Connect()
{
try
{
_transport = new TFramedTransport(new TSocket(_host, _port));
TProtocol protocol = new TBinaryProtocol(_transport);
_client = new Apache.Cassandra.Cassandra.Client(protocol);
_transport.Open();
_client.set_keyspace(_keyspace);
_isConnected = true;
}
catch (Exception ex)
{
log.Error(ex.ToString());
}
return _isConnected;
}
public bool Close()
{
if (_transport.IsOpen)
_transport.Close();
_isConnected = false;
return true;
}
public bool InsertData(Send your data as parameters here)
{
try
{
List<Column> list = new List<Column>();
string strKey = keyvalue;
#region Inserting into Coulmn family
List<Byte> valbytes = new List<byte>(BitConverter.GetBytes(value)); //You might have to pad this with more bytes to make it length of 8 bytes
Column doublecolumn1 = new Column()
{
Name = Encoding.UTF8.GetBytes("column1"),
Timestamp = timestampvalue,
Value = valbytes.ToArray()
};
list.Add(doublecolumn1);
Column stringcolumn2 = new Column()
{
Name = Encoding.UTF8.GetBytes("column2"),
Timestamp = timestampvalue,
Value = Encoding.UTF8.GetBytes("StringValue")
};
list.Add(stringcolumn2);
Column timecolumn3 = new Column()
{
Name = Encoding.UTF8.GetBytes("column3"),
Timestamp = timestampvalue,
Value = BitConverter.GetBytes(DateTime.Now.Ticks)
};
list.Add(timecolumn3);
#endregion
ColumnParent columnParent = new ColumnParent();
columnParent.Column_family = columnFamily;
Byte[] key = Encoding.UTF8.GetBytes(strKey);
foreach (Column column in list)
{
try
{
_client.insert(key, columnParent, column, ConsistencyLevel.QUORUM);
}
catch (Exception e)
{
log.Error(e.ToString());
}
}
return true;
}
catch (Exception ex)
{
log.Error(ex.ToString());
return false;
}
}
public List<YourReturnObject> GetData(parameters)
{
try
{
ColumnParent columnParent = new ColumnParent();
columnParent.Column_family = columnFamily;
DateTime curdate = startdate;
IndexExpression indExprsecondkey = new IndexExpression();
indExprsecondkey.Column_name = Encoding.UTF8.GetBytes("column");
indExprsecondkey.Op = IndexOperator.EQ;
List<Byte> valbytes = PadLeftBytes((int)yourid, 8);
indExprsecondkey.Value = valbytes.ToArray();
indExprList.Add(indExprsecondkey);
IndexClause indClause = new IndexClause()
{
Expressions = indExprList,
Count = 1000,
Start_key = Encoding.UTF8.GetBytes("")
};
SlicePredicate slice = new SlicePredicate()
{
Slice_range = new SliceRange()
{
//Start and Finish cannot be null
Start = new byte[0],
Finish = new byte[0],
Count = 1000,
Reversed = false
}
};
List<KeySlice> keyslices = _client.get_indexed_slices(columnParent, indClause, slice, ConsistencyLevel.ONE);
foreach (KeySlice ks in keyslices)
{
String stringcolumnvalue = Encoding.UTF8.GetString(cl.Column.Value);
double doublevalue= (Double)BitConverter.ToDouble(cl.Column.Value);
long timeticks = BitConverter.ToInt64(cl.Column.Value, 0);
DateTime dtcolumntime = new DateTime(timeticks);
}
}
catch (Exception ex)
{
log.Error(ex.ToString());
}
return yourdatalist;
}
}
}
Now the above class can be used by your webservice, which in turn will be used by Silverlight. Btw, you'll have to take care of other silverlight issues like size of data to be downloaded from server/webservice etc.,
FYI, our client service of Cassandra runs on port 9160..

Background task is skipping schedule, updating every 60 min sometimes

I'm about to loose it soon... I have two apps with working background tasks that are updating the live tile. The data for the live tile is downloaded, parsed and then an image is created dynamically and used as the background for the live tile.
Everything is working just fine for a day or two, but then the updating starts behaving very strange. The first one-two days both live tiles for my apps are updating every 28 minutes like clockwork. But then they start skipping updates. Often app A then updates when app B doesn't update the live tile so that they are not updating at the same time and only once an hour. To put it simple they are way off schedule.
This is really frustrating since I need to be able to rely on the tiles beeing updated every 30 minutes (if I have enough battery, good reception and so on).
I would really appreciate if someone could help me out and maybe take a look at my code to see if there might be something messing up the update interval (like not calling NotifyComplete correctly). I have removed some code and and tried to simplify it. Please ask if you need anything else to understand this.
I have been trying to fix this for the last two months, trying different phones and going throughmy code very carefully.
Your help is more appreciated than you can ever know.
Thanks in advance.
My OnInvoke function:
Timer t = null;
ShellToast toast = new ShellToast();
try
{
HttpWebRequest request = (HttpWebRequest)WebRequest.Create(new Uri(strUrlHBH));
request.Accept = "*/*";
request.AllowAutoRedirect = true;
// disable caching.
request.Headers["Cache-Control"] = "no-cache";
request.Headers["Pragma"] = "no-cache";
t = new Timer(
state =>
{
if (string.Compare(state.ToString(), id, StringComparison.InvariantCultureIgnoreCase) == 0)
{
//logger.Write("Timeout reached for connection [{0}], aborting download.", id);
runNotifyComplete = false;
NotifyComplete();
request.Abort();
t.Dispose();
}
},
id,
timeout,
0);
request.BeginGetResponse(
r =>
{
try
{
if (t != null)
{
t.Dispose();
}
var httpRequest = (HttpWebRequest)r.AsyncState;
var httpResponse = (HttpWebResponse)httpRequest.EndGetResponse(r);
using (var reader = new StreamReader(httpResponse.GetResponseStream()))
{
var response = reader.ReadToEnd();
Deployment.Current.Dispatcher.BeginInvoke(new Action(() =>
{
try
{
//Parse the result
if (boolResult) //If we have a result
{
Grid grid = new Grid();
StackPanel sp = new StackPanel();
sp.Height = 173;
sp.Width = 173;
//StreamResourceInfo info = Application.GetResourceStream(new Uri("Pin-to-start2.png", UriKind.Relative));
if ((bool)settings["LiveTileMetro"] == true)
{
// create source bitmap for Image control (image is assumed to be alread 173x173)
/*WriteableBitmap wbmp2 = new WriteableBitmap(1, 1);
wbmp2.SetSource(info.Stream);
Image img = new Image();
img.Source = wbmp2;
// add Image to Grid
grid.Children.Add(img);
strBackBackground = "Pin-to-start2.png";
}
else
{*/
sp.Background = (SolidColorBrush)Application.Current.Resources["PhoneAccentBrush"];
//sp.Background.Opacity = 0.0;
strBackBackground = "";
}
StreamResourceInfo info;
//GC.Collect();
info = Application.GetResourceStream(new Uri("/MyApp;component/images/Icons/livetile/livetile.png", UriKind.Relative));
WriteableBitmap wbmp3 = new WriteableBitmap(1, 1);
try
{
wbmp3.SetSource(info.Stream);
}
catch
{
}
Image img3 = new Image();
img3.Source = wbmp3;
// add Image to Grid
img3.Width = 173;
img3.Height = 173;
img3.Margin = new Thickness { Left = 0, Bottom = 0, Right = 0, Top = 0 };
TextBlock txtTemperature = new TextBlock();
TextBlock txtTemperatureRing = new TextBlock();
txtTemperature.Foreground = new SolidColorBrush(Colors.White);
txtTemperature.Text = strTemp;
txtTemperature.TextAlignment = TextAlignment.Right;
txtTemperatureRing.Style = (Style)Application.Current.Resources["PhoneTextTitle3Style"];
txtTemperatureRing.FontFamily = new FontFamily("Segoe WP Light");
txtTemperatureRing.FontSize = 40;
txtTemperatureRing.Foreground = new SolidColorBrush(Colors.White);
txtTemperatureRing.Text = "°";
txtTemperatureRing.TextAlignment = TextAlignment.Right;
txtTemperature.FontFamily = new FontFamily("Segoe WP Light");
txtTemperature.FontSize = 60;
txtTemperature.Margin = new Thickness { Left = 0, Bottom = 0, Right = 0, Top = -75 };
txtTemperature.Height = 80;
txtTemperature.Width = 145;
txtTemperatureRing.Margin = new Thickness { Left = 128, Bottom = 0, Right = 0, Top = -97 };
txtTemperatureRing.Height = 50;
txtTemperatureRing.Width = 39;
sp.Children.Add(img3);
sp.Children.Add(txtTemperature);
sp.Children.Add(txtTemperatureRing);
//call measure, arrange and updatelayout to prepare for rendering
sp.Measure(new Size(173, 173));
sp.Arrange(new Rect(0, 0, 173, 173));
sp.UpdateLayout();
grid.Children.Add(sp);
WriteableBitmap wbmp = new WriteableBitmap(173, 173);
wbmp.Render(grid, null);
wbmp.Invalidate();
//write image to isolated storage
string sIsoStorePath = #"\Shared\ShellContent\tile.png";
using (IsolatedStorageFile appStorage = IsolatedStorageFile.GetUserStoreForApplication())
{
//ensure directory exists
String sDirectory = System.IO.Path.GetDirectoryName(sIsoStorePath);
if (!appStorage.DirectoryExists(sDirectory))
{
appStorage.CreateDirectory(sDirectory);
}
using (IsolatedStorageFileStream stream = new IsolatedStorageFileStream(sIsoStorePath, System.IO.FileMode.Create, appStorage))
{
wbmp.SaveJpeg(stream, 173, 173, 0, 100);
}
}
/// If application uses both PeriodicTask and ResourceIntensiveTask
//ShellTile TileToFind = ShellTile.ActiveTiles.FirstOrDefault(x => x.NavigationUri.ToString().Contains("TileID=2"));
ShellTile TileToFind = ShellTile.ActiveTiles.First();
//test if Tile was created
if (TileToFind != null)
{
StandardTileData NewTileData = new StandardTileData
{
BackgroundImage = new Uri("isostore:Shared/ShellContent/tile.png", UriKind.Absolute),
Title = strTitle,
Count = null,
BackTitle = (string)settings["SelectedCityName"],
BackBackgroundImage = new Uri(strBackBackground, UriKind.Relative),
BackContent = strWind + Environment.NewLine + strPrecipitation
};
//ShellTile.Create(new Uri("/MainPage.xaml?TileID=2", UriKind.Relative), NewTileData);
TileToFind.Update(NewTileData);
}
}
if (runNotifyComplete == true)
{
runNotifyComplete = false;
NotifyComplete();
}
}//If matches.count
}
catch
{
if (runNotifyComplete == true)
{
runNotifyComplete = false;
NotifyComplete();
}
}
finally
{
if (runNotifyComplete == true)
{
runNotifyComplete = false;
NotifyComplete();
}
}
}));
}
if (runNotifyComplete == true)
{
runNotifyComplete = false;
NotifyComplete();
}
}
catch
{
// error handling.
if (runNotifyComplete == true)
{
runNotifyComplete = false;
NotifyComplete();
}
}
finally
{
}
},
request);
}
catch
{
if (runNotifyComplete == true)
{
runNotifyComplete = false;
NotifyComplete();
}
}
finally
{
}
EDIT 1: Here is the code for initializing the background task
MessageBox.Show(MyResources.LiveTileToggleMsgBoxText, "Live tile", MessageBoxButton.OK);
//start background agent
PeriodicTask periodicTask = new PeriodicTask("AppPeriodicAgent0440");
periodicTask.Description = "Periodic task for APP that updates the LiveTile .";
periodicTask.ExpirationTime = System.DateTime.Now.AddDays(14);
// If the agent is already registered with the system,
if (ScheduledActionService.Find(periodicTask.Name) != null)
{
ScheduledActionService.Remove("AppPeriodicAgent0440");
}
try
{
//only can be called when application is running in foreground
ScheduledActionService.Add(periodicTask);
}
catch
{
}
EDIT 2:
This code is run everytime I exit the application in order to keep the background task alive. I put it in OnNavigatedFrom to avoid slowing down the start up of the app
//start background agent
PeriodicTask periodicTask = new PeriodicTask("AppPeriodicAgent0440");
periodicTask.Description = "Periodic task for APP that updates the LiveTile.";
periodicTask.ExpirationTime = System.DateTime.Now.AddDays(14);
// If the agent is already registered with the system,
if (ScheduledActionService.Find(periodicTask.Name) != null)
{
ScheduledActionService.Remove("AppPeriodicAgent0440");
}
//only can be called when application is running in foreground
ScheduledActionService.Add(periodicTask);

If you read the Background Agents overview
http://msdn.microsoft.com/en-us/library/hh202942(v=vs.92).aspx you'll see that it details several scenarios where you schedule won't be followed. For example:
Battery Saver mode is an option that the user can enable on the device
to indicate that battery life should be prioritized. If this mode is
enabled, periodic agents may not run, even if the interval has elapsed

There is no guarantee that the scheduled task will run on the expected schedule. It even has a +/- 10 minute clause in the execution timeschedule.
From your question there is no information about how you're recording other events/tasks that may be happenening on the device at the time you're expecting a schedule to run.
In that you have no logging of errors, timeouts or checking of the LastExitReason of the task there could be all sorts of reasons for the behaviour you're seeing.
If I had to guess where the issue is, based on the information you have provided, I'd presume the problem is with the web request (either the network or the server) and an error in the request causes the UI to not be updated.
There is no way to guarantee that the tile will update on a predictable schedule. If you must absolutely have this updated for your circumstances/requirements then this platform isn't going to be able to provide that guarantee.
If you need multiple tiles to be kept in sync I'd approach this by having all the tiles updated by the same process.
This way, even if there is an inconsistency in the updating of the tiles from a time perspective they'll be in sync with each other.