I am using Masstransit to send Request/Response via servicebus between two services(dont ask why).
I would like to set-up custom application insights telemetry. I know that ServiceBus Messages add Diagnostic metadata so consumer can extract it and use it to add correlation between services. However I can't access it in MassTransit, or at least I dont know how.
Any tips?
Couple of months passed and solution i implemented proves to be a good one.
I created class that implements IReceiveObserver. On PreReceive I am able to access (ServiceBusReceiveContext)context and start Telemetry operation that has correct parent id. so it looks like this:
public Task PreReceive(ReceiveContext context)
{
var serviceBusContext = (ServiceBusReceiveContext)context;
var requestActivity = new Activity("Process");
requestActivity.SetParentId(serviceBusContext.Properties["Diagnostic-Id"].ToString());
IOperationHolder<RequestTelemetry> operation = _telemetryClient.StartOperation<RequestTelemetry>(requestActivity);
operation.Telemetry.Success = true;
serviceBusContext.Properties.Add(TelemetryOperationKey, operation);
return Task.CompletedTask;
}
On PostReceive I am able to stop operation:
public Task PostReceive(ReceiveContext context)
{
var serviceBusContext = (ServiceBusReceiveContext)context;
var operation = (IOperationHolder<RequestTelemetry>)serviceBusContext.Properties[TelemetryOperationKey];
operation.Dispose();
return Task.CompletedTask;
}
I also do some magic when exception happens:
public Task ReceiveFault(ReceiveContext context, Exception exception)
{
_telemetryClient.TrackException(exception);
var serviceBusContext = (ServiceBusReceiveContext)context;
var operation = (IOperationHolder<RequestTelemetry>)serviceBusContext.Properties[TelemetryOperationKey];
operation.Telemetry.ResponseCode = "Fail";
operation.Telemetry.Success = false;
operation.Dispose();
return Task.CompletedTask;
}
It was difficult to find this solution by reading MassTransit documentation. I would say that MassTransit is a fantastic tool for some situations there is no alternatives. However documentation is pretty poor.
You can use Application Insights with MassTransit, there is a package available that writes metrics directly.
The documentation is available here:
https://masstransit-project.com/advanced/monitoring/applications-insights.html
Also, you can access Activity.Current from anyway, I think, based on my experience with DiagnosticSource. It might be different with AppInsights though.
Related
I have a razor pages app that implements Quartz.NET to store jobs in a MySQL Database. The implementation works fine so far, I can connect to the db, store jobs and they are executed at the specified times. The issue I'm having currently is that I need to schedule and execute jobs based on user inputs(without restarting the app) and that I can't get to work. I'm very new to Quartz&Asp.net and I haven't been coding for very long either, so apologies if I've made any stupid mistakes.
I've read somewhere that I shouldn't initialize multiple schedulers so I've tried storing the scheduler object I've got so I can access and use it later. However when I try to access it from another class later then I get a Null reference exception. Tbh, this feels like it shouldn't even work so I'm not surprised it doesn't...can anyone please look at my code below and tell me if this can work? Or is there a better way to do this?
I've found one other solution where they basically create a job on startup that periodically checks a db for new jobs and adds them to the scheduler. I guess that would work, seems a bit clunky, though. Plus it's from 10 years ago so maybe there's a better way today? How to add job with trigger for running Quartz.NET scheduler instance without restarting server?
One other idea I've had was to open(and close) a new app whenever I need to create a job. I'm not sure I like that idea but seems less resource intensive than the recurring job described above. Would that be a viable option?
The code for my current solution:
Scheduler:
//Creating Scheduler
Scheduler = await schedulerFactory.GetScheduler();
Scheduler.JobFactory = jobFactory;
var key = new JobKey("Notify Job", "DEFAULT");
if (key == null)
{
//Create Job
IJobDetail jobDetail = CreateJob(jobMetaData);
//Create Trigger
ITrigger trigger = CreateTrigger(jobMetaData);
//Schedule Job
//await Scheduler.ScheduleJob(jobDetail, trigger, cancellationToken);
await Scheduler.AddJob(jobDetail, true);
}
//Start Scheduler
await Scheduler.Start(cancellationToken);
//Copying the scheduler object into a different class where it's easier to access.
ScheduleStore scheduleStore = new ScheduleStore();
scheduleStore.tempScheduler = Scheduler;
ScheduleStore:
public class ScheduleStore
{
public IScheduler tempScheduler { get; set; }
public ScheduleStore()
{
}
}
runtime Scheduler:
public class RunningScheduler : IHostedService {
public IScheduler scheduler { get; set; }
private readonly JobMetadata jobMetaData;
public RunningScheduler(JobMetadata job)
{
ScheduleStore scheduleStore = new ScheduleStore();
this.scheduler = scheduleStore.tempScheduler;
this.jobMetaData = job;
}
public async Task StartAsync(CancellationToken cancellationToken)
{
IJobDetail jdets = CreateJob(jobMetaData);
if (jobMetaData.CronExpression == "--")
{
ITrigger jtriggz = CreateSimpleTrigger(jobMetaData);
//the next line throws the exception.
await scheduler.ScheduleJob(jdets, jtriggz, cancellationToken);
//It's definitely the scheduler that's throwing the null pointer exception.
}
// the else does basically the same as the if, only with a cron trigger instead of a simple one so I've omitted it.
I see that you are using a hosted service. Have you noticed that Quartz has that support already built-in?
Quartz cannot handle new jobs "new code that runs" dynamically, but triggers for sure. You just need to obtain a reference to IScheduler and then you can add new triggers pointing to existing job or just call scheduler.TriggerJob which will call your job once with given parameters (job data map is powerful feature to pass execution parameters).
I'd advice checking the GitHub repository and its examples, there a specific ones for different features and ASP.NET Core and worker integrations.
Generatlly Quartz already has database persistence support which you can use. Just call scheduler methods to add jobs and triggers - they will be persisted and available between application restarts (and take effect immediately without the need for restart).
I'm currently working on many .NET Core API projects and encountered a future possible regression.
How do you guys prevent this situation ?
Here's my architecture :
API project
BusinessLayer
API.UnitTests (references 2))
API.IntegrationTests (references 1 #for the casts))
An integration test example :
[Fact]
public async Task TestGetAll()
{
// Arrange
var query = "api/v1/xxx/getall";
// Act
var response = await _AuthorizedClient.GetAsync(query);
// Assert
Assert.True(response.IsSuccessStatusCode);
var results = JsonConvert
.DeserializeObject<List<MyResult>>(await response.Content.ReadAsStringAsync());
Assert.True(results.Any());
//Assert.AnythingOn(results);
}
Considering the next version and/or my [colleague] maintenance; with my deserializing cast, an update of the MyResult object might be hidden and create a production regression.
I've tried to do my integration test with the dynamic keyword and without casting but it take my much effort.
How do you deal with this situation ?
Are there any best practices ?
[Edit] After some search, I've found this article Differential Regression Testing for REST APIs which looks quite interesting
In my experience, dynamic is not a good practice because it will never fail on build but will fail on execution.
I think you should use something like this :
public static T DeserializeObject<T>(string value)
{
T result = default(T);
try {
result = JsonConvert.DeserializeObject<T>(value);
}
return result;
}
I have a queue listener which makes multiple REST API calls once it receives a message. I want to track those API calls as dependencies using Application Insights. Is there any way of doing it automatically like it happens for ASP.NET Core projects?
I tried something similar to the following code but it does not log the dependencies automatically.
using (var operation = ApplicationLogging.TelemetryClient.StartOperation<RequestTelemetry>("Test"))
{
//Rest Calls
}
The standard dependency-tracking module automatically discovers external dependencies such as databases and REST APIs. But you might want some additional components to be treated in the same way. You can write code that sends dependency information, using the same TrackDependency API that is used by the standard modules.
Use the TrackDependency call to track the response times and success rates of calls to an external piece of code. The results appear in the dependency charts in the portal.
Snippet in C#
var success = false;
var startTime = DateTime.UtcNow;
var timer = System.Diagnostics.Stopwatch.StartNew();
try
{
success = dependency.Call();
}
finally
{
timer.Stop();
telemetry.TrackDependency("myDependency", "myCall", startTime, timer.Elapsed, success);
// With the Latest SDK follow the below format:
// TrackDependency (string dependencyTypeName, string dependencyName, string data, DateTimeOffset startTime, TimeSpan duration, bool success);
}
Documentation Reference
Hope this helps.
I've make some codes implementing some web API.
This API method returns last record of Foo Table.
public class FooController : ApiController
{
private FooContext db = new FooContext();
// GET: api/Foo
[ResponseType(typeof(Foo))]
public async Task<IHttpActionResult> GetLastFoo()
{
Foo foo = await db.Foo.Last();
if (foo == null)
{
return NotFound();
}
return Ok(foo);
}
}
I want make this API asynchronous, but there is no LastAsync() method.
Why and how can I solve it?
Thanks in advance.
You should not use Task.Run in ASP.NET:
Async and await on ASP.NET are all about I/O. They really excel at
reading and writing files, database records, and REST APIs. However,
they’re not good for CPU-bound tasks. You can kick off some background
work by awaiting Task.Run, but there’s no point in doing so. In fact,
that will actually hurt your scalability by interfering with the
ASP.NET thread pool heuristics. If you have CPU-bound work to do on
ASP.NET, your best bet is to just execute it directly on the request
thread. As a general rule, don’t queue work to the thread pool on
ASP.NET.
From Async Programming : Introduction to Async/Await on ASP.NET
Still it does not mean you can't use async and await in ASP.NET for I/O (and that's what you want) just use real async methods and not a fake async wrappers over synchronous methods (that will just push the work into other ThreadPool thread and you will not gain any performance benfit from it).
Since you don't have LastAsync method in EF I suggest you to use OrderBy to order your collection as you want and to use FirstAsync method (or FirstAsync overload that supports lambda predicate) instead of using Last method, FirstAsync is a true async I/O method that is supported in EF.
More info about when it's appropriate to use Task.Run can be found in Task.Run Etiquette Examples: Don't Use Task.Run in the Implementation article in Stephen Cleary's blog.
Your question why there is no LastAsync method in the first place should be directed to the team at Microsoft that desiged EF api, but my guess is that they didn't bother implementing it since it is so easy to achieve the same functionally with FirstAsync method as I suggested.
A working version of that code would look like this:
public class FooController : ApiController
{
private FooContext db = new FooContext();
// GET: api/Foo
[ResponseType(typeof(Foo))]
public async Task<IHttpActionResult> GetLastFoo()
{
Foo foo = await db.Foo.OrderByDesc(x=> x.Timestamp).FirstOrDefaultAsync();
if (foo == null)
{
return NotFound();
}
return Ok(foo);
}
}
Last etc don't work against an EF IQueryable because SQL doesn't have an equivalent command
about how to solve it
you can use
await Task.Run(()=>db.Foo.Last());
I’m about to start work on an OpenRasta project (an xml over http web service). OpenRasta looks great but unfortunately worked examples seem few and far between on the internet. Looking at the test side of the project, if my handlers are returning strongly typed objects (not OperationResult), i.e.:
public class PersonHandler
...
public Person Get(int id)
{
...
How can I test for http status codes? (For example if the handler throws an uncaught exception). I’m not sure what level the tests pitch in at, and what needs mocking (using moq btw)
Any help appreciated, particularly coded examples!
I faced the same problem, and ended up writing my tests as integration tests at a much higher level, actually making real REST/HTTP calls through a simple HttpWebRequest client. This allowed me to check the HTTP response headers / status codes and double-check the JSON/XML serialization from the client's perspective, which was just as important as whether or not the operations succeeded.
I started by returning OperationResult from all my handlers, and used these to wrap the strongly-typed objects. My handlers all inherit from a base class with a few helper methods that make it easier to return a custom error with a user-friendly error message. The more I coded this up, the more my handlers resembled a ASP.NET MVC controller. e.g.:
public OperationResult GetById(int id)
{
try
{
// do stuff here
return OKResult( // some strongly-typed resource );
}
catch(SomeException ex)
{
return BadRequestResult(SomeErrorCode, ex.Message);
}
}
Then in the test client, it's pretty easy to just check the HTTP status code. Obviously this doesn't help much with mocking. I'm not sure what the best solution is, in fact I've favorited this question in the hope that someone answers it better than I can - but this has worked pretty well for me so far.
The handler is just a class--ideally with minimal dependencies--so your unit tests can just test the isolated logic in the class.
If you want to test for status codes, I recommend (based on very little experience!) using OpenRasta self-hosting.
Here's a test (somewhat changed) that I wrote recently:
[TestMethod]
public void POST_with_inaccurate_contentLength_returns_405()
{
var resource = GetResource();
IRequest request = new InMemoryRequest
{
HttpMethod = "POST",
Uri = new Uri("http://localhost/Resource"),
};
request.Headers.ContentLength = 16; //wrong!
request.Entity.Stream.Write(resource.Content, 0, resource.Content.Length);
var response = _host.ProcessRequest(request);
Assert.AreEqual(405, response.StatusCode);
}
I should add that the host is set up in the TestInitialize method as such:
_host = new InMemoryHost(new Configuration());
_host.Resolver.AddDependencyInstance(typeof(IFileResourceRepository), _repository, DependencyLifetime.Singleton);
...and is cleaned up in the TestCleanup method.