I have a free account with Azure (90 day trial) and I'm finding that my worker role is erroring out. I don't have any of the monitoring features enabled because I believe they cost money.
Is there any way for me to log the errors and store them somewhere where I can retrieve them without having to upgrade my account to a paid account?
You can attach an event for unhandled exceptions in worker role OnStart() method.
public override bool OnStart()
{
AppDomain.CurrentDomain.UnhandledException += new UnhandledExceptionEventHandler(CurrentDomain_UnhandledException);
bool result = base.OnStart();
Trace.TraceInformation("ReceiverRole has been started");
return result;
}
private void CurrentDomain_UnhandledException(object sender, UnhandledExceptionEventArgs e)
{
Trace.TraceError("Unhandled exception in worker role: {0}", e.ExceptionObject);
}
What I've found myself that is was quite time consuming to implement the Azure Diagnostics, and the best way so far, was to launch the Azure Emulator on my machine, and see what error's it shows.
What You do, is simple set up Your Azure project as startup and run it.
Or right click on the Azure project and select : Debug -> Start New Instance
To take a look at (Windows Azure Diagnostics) which will allow you to collect diagnostics data (trace logs, event logs, perf. counters etc.) for your worker role. Depending on the configuration, this diagnostics data can be persisted into Windows Azure Table storage. You can view the diagnostics data using any storage explorer.
The skinny cheap way is to add to the role error handler that sends the exception contents with stack to an StorageAccount table. You can use a cloud storage browser to view the table contents to see the details of the exception. This could be matured over time to have a nice 'in house' app that downloads the table contents into SS and create a smart client that can browse the errors.
I have this system implemented in a way that I can set verbosity and address the timestamps via UTC. The logging is done in a separate worker role so that the 'production' roles post to a queue which is alot faster for the failing role to deal with.
Related
Ive made an app that uses Azure easy tables and connects using the following:
try
{
await ctv.combatDrillsTable.Initialization;
await ctv.combatDrillsTable.InitLocalStoreAsync();
await AddItemsAsync();
}
catch
{
var addError = new MessageDialog("Connection to your drills could not be established at this time, returning to " +
"main menu");
await addError.ShowAsync();
if (MainPage.MyFrame.CanGoBack)
{
MainPage.MyFrame.GoBack();
}
}
This was doing a GET request fine the last few weeks but now the connection error throws, I checked my Azure portal and the drills are there, the server overview shows the following:
HTTP Error stats
Im not really sure whats wrong and why Azure has just decided to stop working. I get the same results on bith my local machince is Visual Studio 2017 and the app installed on windows from the store.
Im not really sure whats wrong and why Azure has just decided to stop working.
Firstly, you need to enable logs in Azure, in that case you could access the information logged by Azure and check the logs to find the detail reason. Details for how to do please reference this article.
Since you're using easy table, the azure backend should be node.js. After enabled logs, you could access logs by address like: https://{your app name}.scm.azurewebsites.net/api/vfs/LogFiles/Application/index.html.
If you still cannot resolve your issues by checking the log details, you could upload the log for further looking.
As I understand Azure Worker roles run by the help of Host application called WaWorkerHost.exe and there is another application called WaHostBootstrapper.exe which checks if WaWorkerHost.exe is running and if not it will run the WaWorkerHost.exe.
How often does this 'worker role status check' occurs?
How can I quickly restart the Worker role myself? I can either reboot the machine worker role is running and wait for few minutes or chose the following traditional method:
Taskkill /im /f WaWorkerHost.exe
and wait for few minutes for the WaHostBootstrapper.exe to kick in but this very inefficient and slow.
Is there any (instant)method of restarting the worker role?
Can I run something like the following and expect similar results to the WaHostBootstapper.exe or there are other consideration?
WaWorkerHost.exe {MyAzureWorkerRole.dll}
The bootstrapper checks the WaWorkerHost status every 1 second.You can see it in the bootsrapper logs (c:\resources\WaHostBootstrapper.txt), by looking at interval of the trace:
"Getting status from client WaWorkerHost.exe"
You can use AzureTools which is a utility used by Azure support team.
One of the its features is gracefully recycle the role instance:
Alternatively, you can restart the instance programmatically:
Upload management certificate to your subscription.
Use the following code to programmatically restart the instance:
Using Microsoft Azure Compute Management library:
X509Certificate2 cert = new X509Certificate2("");
var credentials = new CertificateCloudCredentials("your_subscription_id", cert);
using (var managementClient = new ComputeManagementClient(credentials))
{
OperationStatusResponse response =
await managementClient.Deployments.RebootRoleInstanceByDeploymentSlotAsync(
"cloud_service_name",
DeploymentSlot.Production, // or staging
"instance_name");
}
This is not recommended, for three reasons:
The bootsrapper checks every second, which should be enough for most cases.
It could lead to weird issues. For example, you kill the worker, bootstrapper identifies that the worker is down, you manually start the worker, bootstrapper also tries to start the worker and fail (will crash? will enter zombie state?). It can lead to unhealthy bootstrapper, means that nothing takes care of the worker process.
It depends, of course, on what's the bootstrapper does other than starting the worker. But even if it is currently does nothing other than starting the role, you cannot know for sure if tomorrow Azure team will decide to add it more responsibilities/actions.
If the role itself is aware that it needs to restart, it can call RoleEnvironment.RequestRecycle to cause the role instance to be restarted.
I have the following functions in the same web job console app that uses the azure jobs sdk and its extensions. The timed trigger queries an API end point for a file, does some additional work on it and then saves the file to the blob named blahinput. Now the second method "ProcessBlobMessage" is supposed to identify the new blob file in the blahinput and do something with it.
public static void ProcessBlobMessage([BlobTrigger("blahinput/{name}")] TextReader input,
string name, [Blob("foooutput/{name}")] out string output)
{//do something }
public static void QueryAnAPIEndPointToGetFile([TimerTrigger("* */1 * * * *")] TimerInfo timerInfo) { // download a file and save it to blob named blah input}
The problem here is :
When I deploy the above said web job as continuous, only the timer triggered events seems to get triggered while the function that is supposed to identify the new file never gets triggered. Is it not possible to have two such triggers in the same web job?
From this article: How to use Azure blob storage with the WebJobs SDK
The WebJobs SDK scans log files to watch for new or changed blobs. This process is not real-time; a function might not get triggered until several minutes or longer after the blob is created. In addition, storage logs are created on a "best efforts" basis; there is no guarantee that all events will be captured. Under some conditions, logs might be missed. If the speed and reliability limitations of blob triggers are not acceptable for your application, the recommended method is to create a queue message when you create the blob, and use the QueueTrigger attribute instead of the BlobTrigger attribute on the function that processes the blob.
Until the new blob trigger strategy is released, BlobTriggers are not reliable. The trigger is based on Azure Storage Analytics logs which stores logs on a Best-Effort basis.
There is an ongoing Github issue about this and there is also a PR regarding a new Blob scanning strategy.
This being said, check if you are using the Latest Webjobs SDK version 1.1.1 because there was an issue on prior versions that could lead to problems on BlobTriggers.
I've been working to try and convert Microsoft's EWS Streaming Notification Example to a service
( MS source http://www.microsoft.com/en-us/download/details.aspx?id=27154).
I tested it as a console app. I then used a generic service template and got it to the point it would compile, install, and start. It stops after about 10 seconds with the ubiquitous "the service on local computer started and then stopped."
So I went back in and upgraded to C# 2013 express and used NLog to put a bunch of log trace commands to so I could see where it was when it exited.
The last place I can find it is in the example code, SynchronizationChanges function,
public static void SynchronizeChanges(FolderId folderId)
{
logger.Trace("Entering SynchronizeChanges");
bool moreChangesAvailable;
do
{
logger.Trace("Synchronizing changes...");
//Console.WriteLine("Synchronizing changes...");
// Get all changes since the last call. The synchronization cookie is stored in the
// _SynchronizationState field.
// Only the the ids are requested. Additional properties should be fetched via GetItem
//calls.
logger.Trace("Getting changes into var changes.");
var changes = _ExchangeService.SyncFolderItems(folderId, PropertySet.IdOnly, null, 512,
SyncFolderItemsScope.NormalItems,
_SynchronizationState);
// Update the synchronization cookie
logger.Trace("Updating _SynchronizationState");
the log file shows the trace message ""Getting changes into var changes." but not the "Updating _SynchronizationState" message.
so it never gets past var changes = _ExchangeService.SyncFolderItems
I cannot for the life figure out why its just exiting. There are many examples of EWS streaming notifications. I have 3 that compile and run just fine but nobody as far as I can tell has posted an example of it done as a service.
If you don't see the "Updating..." message it's likely the sync threw an exception. Wrap it in a try/catch.
OK, so now that I see the error, this looks like your garden-variety permissions problem. When you ran this as a console app, you likely presented the default credentials to Exchange, which were for your login ID. For a Windows service, if you're running the service with one of the built-in accounts (e.g. Local System), your default credentials will not have access to Exchange.
To rectify, either (1) run the service under the account you did the console app with, or (2) add those credentials to the Exchange Service object.
I have a Worker Role that executes code (fetching data and storing it to Azure SQL) every X hours. The timing is implemented using a Thread.Sleep in the while(true) loop in the Run method.
In the Web Role I want to have the abillity to manualy start the code in Worker Role (manualy fecth and store data in my case). I found out that the whole Worker Role can be restarted using the Azure Management API but it seems like an overkill, especialy looking at all the work needed around certificates.
Is there a better way to restart Worker Role from Web Role or have the code in Worker Role run on demand from the Web Role?
Anything like posting an event to an Azure Queue, posting a blob to Azure Blobs, changing a record in Azure Tables or even making some change in SQL Azure will work - the web role will do the change and the worker role will wait for that change. Perhaps Azure Queues would be the cleanest way, although I'm not sure.
One very important thing you should watch for is that if you decide to use polling - like query a blob until it appears - you should insert a delay between the queries, otherwise this code:
while( true ) {
if( storage.BlobExists( blobName ) ) {
break;
}
}
will rush into the storage and you'll encounter outrageous transaction fees. In case of SQL Azure you will not see any fees, but you'll waste the service capacity for no good and this will slow down other operations you queue to SQL Azure.
This is how is should be done:
while( true ) {
if( storage.BlobExists( blobName ) ) {
break;
}
// value should not be less that several hundred (milliseconds)
System.Threading.Thread.Sleep( 15 * 1000 );
}
Well I suggest you use Azure Fluent Management (which uses the Service Management API internally). Take a look at the "Deploying to Windows Azure" page.
What you will want to do is the following:
Cloud Service: mywebapp.cloudapp.net
Production slot
Role: MyMvcApplication
Cloud Service: mybackgroundworker.cloudapp.net
Production slot
No DEPLOYMENT
So you would typically have a Cloud Service running with a Web Role and that's it. What you do next is create the Worker Role, add your code, package it to a cspkg file and upload it to blob storage.
Finally you would have some code in your Web Role that can deploy (or remove) the Worker Role to that other Cloud Service by downloading the package locally and then running code similar to this:
var subscriptionManager = new SubscriptionManager(TestConstants.SubscriptionId);
var deploymentManager = subscriptionManager.GetDeploymentManager();
deploymentManager
.AddCertificateFromStore(Constants.Thumbprint)
.ForNewDeployment(TestConstants.HostedServiceName)
.SetCspkgEndpoint(#"C:\mypackage")
.WithNewHostedService("myelastatestservice")
.WithStorageAccount("account")
.AddDescription("my new service")
.AddLocation(LocationConstants.NorthEurope)
.GoHostedServiceDeployment();