I was following the SignalR documentation on Github to message a group. I join just fine with:
Groups.Add(Context.ConnectionId, "foo");
But then when I try and send a message to all the users in that group with:
Clients.Group("foo").syncShortList(id);
I get an exception. I know there's nothing wrong with 'id'. The code will never continue after this line, so I set the debugger to catch all thrown exceptions, and found out that the second line throws the exception:
'Microsoft.AspNet.SignalR.Hubs.GroupProxy' does not contain a definition for 'syncShortList'
I know for sure that I'm listening for the event in javascript:
funnelHub.client.syncShortList = function (id) {
console.log("syncing");
console.log(id);
}
The event is never getting fired. Does anyone see where I'm going wrong with this? I'm running SignalR 1.0.1
As discussed in https://jabbr.net/#/rooms/signalr the error is a First Chance Runtime Binder exception that happens on the first invoke on the group dynamic object. In the end it's harmless.
Related
Having a Firebase Callable Function, for "handled" errors (not exceptions) occurring during execution, I throw new HttpsError(...)'s to notify the client that an error occurred and handle them appropriately.
For monitoring the healthiness of the Cloud Functions, I'm using Google Cloud Monitoring. Therefore I wanted to set up an alert that alerts based on the following query if something really goes wrong (unhandled exception, whatever other errors could occur during function execution):
What I want to have is exception alerting - so if a Cloud Function fails because during an execution an uncaught exception gets thrown, I want to be alerted.
But I do not want this alert to fire if I intentionally "return" (throw) this special HttpsError which is thrown in cases of misuse or "handled" errors (like authentication failure):
throw new HttpsError('permission-denied', 'Access denied')
My question is now whether Cloud Functions that throw HttpsError(...) count as status = "error" or if they count as status = ok in Cloud Monitoring.
My feeling is they count as error (as the alert fires sometimes) but if I then look in the Firebase Console's Function log, they do not show up as error there. So they do not have the red exclamation mark:
Instead there, the log just says something like ...finished with status code: 204
That's what makes me wonder if an error in Cloud Monitoring is just every function that ended with "Http Status code != 200"
If throwing an HttpsError does count as error, how could I query only functions that crashed/did not execute as intended for my alert?
I'm throwing an error from my callable Firebase function:
throw new functions.https.HttpsError(
'invalid-argument',
`Invalid token ${token} for file ${fileName}.`
);
I the logs I see only the following:
12:29:22.500 PM SQR-cancelAllotment Function execution took 1779 ms, finished with status code: 400
12:29:20.722 PM SQR-cancelAllotment Function execution started
So, code 400 is indicated without any error message. Why?
I wouldn’t like to duplicate the error message in a separate console.error.
Throwing an HttpsError is a signal to the client that the function didn't work as expected. It's not an indication that the function terminated with a crash (which would be logged). When you throw an HttpsError, if you want to see a message in the log, you should also make a call to console.error() (or whatever log level you want) in order for that to show up.
For throwing errors in Cloud Functions you could use the Stackdriver Error Reporting client libraries
Here you can find the documentation for setting up the error reporting ( you have some examples there,also)
I am using C++/winRT UWP to discover and connect to Bluetooth Low Energy devices. I am using the advertisment watcher to look for advertisements from devices I can support. This works.
Then I pick one to connect to. The connection procedure is a little weird by my way of thinking but according to the microsoft docs one Calls this FromBluetoothAddressAsync() with the BluetoothAddress and two things happen; one gets the BluetoothLEDevice AND a connection attempt is made. One needs to register a handler for the connection status changed event BUT you can't do that until you get the BluetoothLEDevice.
Is there a timing issue causing the exception? Has the connection already happened BEFORE I get the BluetoothLEDevice object? Below is the code and below that is the log:
void BtleHandler::connectToDevice(BluetoothLEAdvertisementReceivedEventArgs eventArgs)
{
OutputDebugStringA("Connect to device called\n");
// My God this async stuff took me a while to figure out! See https://msdn.microsoft.com/en-us/magazine/mt846728.aspx
IAsyncOperation<Windows::Devices::Bluetooth::BluetoothLEDevice> async = // assuming the address type is how I am to behave ..
BluetoothLEDevice::FromBluetoothAddressAsync(eventArgs.BluetoothAddress(), BluetoothAddressType::Random);
bluetoothLEDevice = async.get();
OutputDebugStringA("BluetoothLEDevice returned\n");
bluetoothLEDevice.ConnectionStatusChanged({ this, &BtleHandler::onConnectionStatusChanged });
// This method not only gives you the device but it also initiates a connection
}
The above code generates the following log:
New advertisment/scanResponse with UUID 00001809-0000-1000-8000-00805F9B34FB
New ad/scanResponse with name Philips ear thermometer and UUID 00001809-0000-1000-8000-00805F9B34FB
Connect to device called
ERROR here--> onecoreuap\drivers\wdm\bluetooth\user\winrt\common\bluetoothutilities.cpp(509)\Windows.Devices.Bluetooth.dll!03BEFDD6: (caller: 03BFB977) ReturnHr(1) tid(144) 80070490 Element not found.
ERROR here--> onecoreuap\drivers\wdm\bluetooth\user\winrt\device\bluetoothledevice.cpp(428)\Windows.Devices.Bluetooth.dll!03BFB9B7: (caller: 03BFAF01) ReturnHr(2) tid(144) 80070490 Element not found.
BluetoothLEDevice returned
Exception thrown at 0x0F5CDF2F (WindowsBluetoothAdapter.dll) in BtleScannerTest.exe: 0xC0000005: Access violation reading location 0x00000000.
It sure looks like there is a timing issue. But if it is, I have no idea how to resolve it. I cannot register for the event if I don't have a BluetoothLEDevice object! I cannot figure out a way to get the BluetoothLEDevice object without invoking a connection.
================================ UPDATE =============================
Changed the methods to IAsyncAction and used co_await as suggested by #IInspectable. No difference. The problem is clearly that the registered handler is out of scope or something is wrong with it. I tried a get_strong() instead of a 'this' in the registration, but the compiler would not accept it (said identifier 'get_strong()' is undefined). However, if I commented out the registration, no exception is thrown but I still get these log messages
onecoreuap\drivers\wdm\bluetooth\user\winrt\common\bluetoothutilities.cpp(509)\Windows.Devices.Bluetooth.dll!0F27FDD6: (caller: 0F28B977) ReturnHr(3) tid(253c) 80070490 Element not found.
onecoreuap\drivers\wdm\bluetooth\user\winrt\device\bluetoothledevice.cpp(428)\Windows.Devices.Bluetooth.dll!0F28B9B7: (caller: 0F28AF01) ReturnHr(4) tid(253c) 80070490 Element not found.
But the program continues to run an I continue to discover and connect. But since I can't get the connection event it is kind of useless at this stage.
I hate my answer. But after asynching and co-routining everything under the sun, the problem is unsolvable by me:
This method
bluetoothLEDevice = co_await BluetoothLEDevice::FromBluetoothAddressAsync(eventArgs.BluetoothAddress(), BluetoothAddressType::Random);
returns NULL. That should not happen and there is not much I can do about it. I read that as a broken BLE API.
A BTLE Central should be able to do as follows
Discover a device if new then:
If user selects connect, connect to
the device
perform service discovery
read/write/enable
characteristics as needed
handle indications/notifications
If at any time the peripheral sends a security request or insufficient authentication error, start pairing
repeat the action that caused the insufficient authentication.
On disconnect, save the paired and bonded state if the device is pairable.
On rediscovery of the device, if unpaired (not a pairable device)
repeat above
If paired and bonded
start encryption
work with the device; no need to re-enable or do service discovery
========================= MORE INFO ===================================
This is what the log shows when the method is called
Connect to device called
onecoreuap\drivers\wdm\bluetooth\user\winrt\common\bluetoothutilities.cpp(509)\Windows.Devices.Bluetooth.dll!0496FDD6: (caller: 0497B977) ReturnHr(1) tid(3b1c) 80070490 Element not found.
onecoreuap\drivers\wdm\bluetooth\user\winrt\device\bluetoothledevice.cpp(428)\Windows.Devices.Bluetooth.dll!0497B9B7: (caller: 0497AF01) ReturnHr(2) tid(3b1c) 80070490 Element not found.
BluetoothLEDevice returned is NULL. Can't register
Since the BluetoothLEDevice is NULL, I do not attempt to register.
================= MORE INFO ===================
I should also add that taking an over-the-air sniff reveals that there is never a connection event. Though the method is supposed to initiate a connection as well as return the BluetoothLEDevice object, it ends up doing neither. My guess is that the method requires more pre-use setup of the system that only the DeviceWatcher does. The AdvertisementWatcher probably does not.
In BLE you always have to wait for every operation to complete.
I am not an expert in C++, but in C# the async connection procedure returns a bool if it was successful.
In C++ the IAsyncOperation does not have a return type, so there is no way to know if the connection procedure was successful or completed.
You will have to await the IAsyncOperation and make sure that you have a BluetoothLEDevice object, before you attach the event handler.
To await an IAsyncOperation there is a question/answer on how to await anIAsyncOperation:
How to wait for an IAsyncAction? How to wait for an IAsyncAction?
Is there anyway to log message contents when an exception occurs?
I looked at various logging extensions but they are just logging CorrelationId. And message contents are not available.
There is a CurrentMessge property in MessageContext, but that is not available at the time logger writes the exception.
I tried to handle PoisonMessage Event, which allows me to log the message contents.
public static void OnPoisonMessage(IBus bus, ReceivedTransportMessage receivedTransportMessage, Rebus.Bus.PoisonMessageInfo poisonMessageInfo) {
var message = new JsonMessageSerializer().Deserialize(receivedTransportMessage);
Log.Error("{#messageType} failed {#message}", message.Messages[0].GetType(), message);
}
This works great, but now I have two errors in the log one coming from my handler and the other coming from logger.
I am wondering if there is a better way to handle this requirement.
If your requirement is to simply log the message contents as JSON, I think you've found the right way to do it - at least that's the way I would have done it.
I'm curious though as to what problem you're solving by logging the message contents - you are aware of the fact that the failing message will end up in an error queue where you can inspect it?
If you're using MSMQ, you can inspect JSON-serialized messages using Rebus' Snoop-tool, which is a simple MSMQ inspector. It will also allow you to move the message back into the input queue where it failed ("return to source queue")
A good way to monitor your Rebus installation is to set up some kind of alerts when something arrives in an error queue, and then you can look at the message (which event includes the caught exceptions in a special header) and then resolve the situation from there.
I am using java API to interact with MQ.
When I try to get a message from an empty queue, I get exception.
Ok, but when I control it with try catch, I am expecting not prompted any error message in console.
but I get!!
try {
queue.get(getMessage, new MQGetMessageOptions());
return getMessage.readUTF();
} catch (Exception e) {
return "";
}
get in console as "MQJE001: Completion Code '2', Reason '2033'."
How can I disable this information output?
how can I check message availability or current queue size?
Thanks
First question: How can I disable this information output?
This link might help: Hide Java Output
Second question: How can I check message availability or current queue size?
MQQueue.getCurrentDepth() method will get you the current queue size. But you must note that this may not represent the correct queue depth at all times as messages could be consumed by other applications from the same queue. Actually you should not worry about queue depth. It is best practice to keep consuming messages and handle 2033 (MQJE001: MQRC_NO_MSG_AVAILABLE) exception which is thrown when there are no messages in the queue in your application.
Easiest method is using MQException.log=null line in your application.
Details bellow:
https://www.ibm.com/support/knowledgecenter/SSFKSJ_7.5.0/com.ibm.mq.dev.doc/q031000_.htm