[Service Bus] Detect connection status

[giggio]

Right now it does not seem possible to detect the connection state with Azure Service Bus. There is no property that indicates if we are connected or if there is some connectivity issue (or other issue, like subscription deleted etc).

Describe the solution you'd like
I want a boolean property on the SubscriptionClient that tells me if it is connected. And I want an event on connection changes, i.e. Connected and Disconnected.

Describe alternatives you've considered
The alternative I'm using now uses Reflection, which is fragile. It does a little bit like this:

var subscriptionClient = new SubscriptionClient(connStr, topic, subscription, ReceiveMode.PeekLock);
var conn = subscriptionClient.ServiceBusConnection;
FaultTolerantAmqpObject<AmqpConnection> connectionManager = (FaultTolerantAmqpObject<AmqpConnection>)typeof(ServiceBusConnection).GetProperty("ConnectionManager", BindingFlags.Instance | BindingFlags.NonPublic).GetMethod.Invoke(conn, null);
var amqpConnection = await connectionManager.GetOrCreateAsync(TimeSpan.FromSeconds(2));
var amqpSessionSettings = new AmqpSessionSettings { Properties = new Fields() };
while (true)
{
    var session = amqpConnection.CreateSession(amqpSessionSettings);
    var connected = false;
    try
    {
        await session.OpenAsync(TimeSpan.FromSeconds(2));
        await session.CloseAsync(TimeSpan.FromSeconds(2));
        connected = true;
    }
    catch (TimeoutException)
    {
    }
    Console.WriteLine(connected);
    Thread.Sleep(2000);
}

Additional context
I'll use this to inform the healthcheck of a container on a Kubernetes environment.

We shouldn't need to have to use reflection. And I get that the library is resilient and will reconnect. But I need to setup scaling, alerts and other infrastructure based on the fact that there is a worker doing what it is supposed to be doing. If for some reason a container gets disconnected from Service Bus, I need to know, I might setup infrastructure that will recreate it, setup alarms, etc. My queues/topics might be filling up, and I don't get to react to it.

[ghost]

Thanks for the feedback! We are routing this to the appropriate team for follow-up. cc @jfggdl

[ghost]

Thanks for the feedback! We are routing this to the appropriate team for follow-up. cc @jfggdl

[AlexGhiondea]

/cc @binzywu.

Also, @jsquire to see how this feedback applies to our Track 2 libraries.

[jfggdl]

@giggio, thanks for opening this issue.
@axisc or @makam: Is there a way we can expose the connection status from the service to the SDKs, if that is not currently the case?

[axisc]

We'll investigate this and add to the backlog.

[SeanFeldman]

I want a boolean property on the SubscriptionClient that tells me if it is connected.

That property exists on all clients, including SubscriptionClient - IsClosedOrClosing.

[giggio]

That property exists on all clients, including SubscriptionClient - IsClosedOrClosing.

If we pull the network cable and put the computer on airplane mode, so cutting all network communication, that property still shows as false. So we cannot rely on it.

[SeanFeldman]

I did not claim you can rely on it, just pointed out there there is a property that is supposed to indicate what's the state of the connectivity. The fact that it doesn't work as it supposed to is a bug that should be looked into (@axisc might already know about it).

For the scenario you've described, you really need not a property, but an event. Which you've also mentioned. That would be a feature as today it doesn't exist AFAIK.

[tomkerkhove]

This is a great feature request - We'd like to use this as well so that we can use it as part of our health probe approach.

THis is important as Kubernetes requires this to kill dead pods and recreate them.

[giggio]

@tomkerkhove This is exactly what I need to do and the reason I opened this issue.

[tomkerkhove]

Any feedback/timeline on this one @axisc?

[tomkerkhove]

While we're asking, would be good if there's a built-in .NET Core Health Check that works with this feature

[giggio]

Everyone interested in this issue, please add your 👍 up there so they can prioritize it.

[ghost]

Hi @giggio. Thank you for opening this issue and giving us the opportunity to assist. We believe that this has been addressed. If you feel that further discussion is needed, please add a comment with the text “/unresolve” to remove the “issue-addressed” label and continue the conversation.

[SeanFeldman]

@jsquire or @JoshLove-msft, is this API documented anywhere?

[jsquire]

@SeanFeldman: Documentation can currently be found on MS Docs:

• ServiceBusClientOptions.EnableTransportMetrics
• ServiceBusClient.GetTransportMetrics
• ServiceBusTransportMetrics

I'll defer to @JoshLove-msft for any additional sources and future plans.

[SeanFeldman]

Based on what I’ve seen in the past, XML docs don’t provide as much help to the teams that don’t use ASB extensively as elaborate documentation. Just in the links above, I can see that two steps are required to get the metrics.

Adding it to Diagnostics section could be a good start.

[sohanlal311]

@JoshLove-msft Could you please point me out to the Java API for the same?

[sohanlal311]

/unresolve

[ghost]

Hi sohanlal311, only the original author of the issue can ask that it be unresolved. Please open a new issue with your scenario and details if you would like to discuss this topic with the team.

[sohanlal311]

@JoshLove-msft Could you please point me out to the Java API for the same?

[JoshLove-msft]

Hi @sohanlal311 this feature is not yet available in the Java library.
/cc @ki1729

[sohanlal311]

@JoshLove-msft Could you please let me know if we need to open another issue for Java version?

[JoshLove-msft]

@JoshLove-msft Could you please let me know if we need to open another issue for Java version?

@ki1729 do you know if there is already a Java version of this issue file?

[JoshLove-msft]

Reopening so that we can collect feedback on the beta feature before GA.

[ghost]

Hi @giggio, since you haven’t asked that we “/unresolve” the issue, we’ll close this out. If you believe further discussion is needed, please add a comment “/unresolve” to reopen the issue.

[sohanlal311]

@ki1729 Could you please let me know if there is already a Java version of this issue?

[sohanlal311]

@ki1729 Could you please provide an update on this one?

[sohanlal311]

@JoshLove-msft Could you please let me know if there is already a Java version of this issue?

[stliu]

@JoshLove-msft @joshfree @shankarsama seems this is not resolved yet, shall we reopen it? we have #21976 depends on it as well

[joshfree]

@stliu let's open a new issue in https://github.com/azure/azure-sdk-for-java/ repo for the Java SDK specific ask, and we can link that back to here; rather than adding Java noise to the .NET repo. :)

[stliu]

ah, my mistake didn't check the repo :)

[ki1729]

@stliu I have created a new issue in the Java repo to track this feature request : Azure/azure-sdk-for-java#30507

[ki1729]

@sohanlal311 : The corresponding issue for Java is here: Azure/azure-sdk-for-java#30507

[scgbear]

@jsquire or @JoshLove-msft, there an ETA on when ServiceBusTransportMetrics will make it's way out of the https://www.nuget.org/packages/Azure.Messaging.ServiceBus/7.8.0-beta.2 package ?

All of the links to documentation you provided above resolve to a 404.

This feature die on the vine?

Are there alternative approaches we should be taking to solve the problem of determining connection status?

[JoshLove-msft]

@scgbear, yes we are planning on taking a different approach here. @lmolkova do you have any timelines for when the metrics work will begin for .NET?

[bar10dr]

How on earth does it take more than three years to implement two simple events that informs of a connection state change?

This is such a low level basic feature.

Is the plan to bind this functionality into some sort of premium tier or additional paid service?