NotSupportedException when publishing message

Repro:

Not really a repro possible. We have published millions of messages through nats.net and never encountered this issue. However, for a single published message we logged a NotSupportedException. I will see if I can find out more, but given that this is virtually impossible to reproduce I can’t do much more than staring at the code.

Expected:

Publishing a message through nats.net should not throw a NotSupportedException

Actual:

A NotSupportedException (apparently trying to seek a NetworkStream) is thrown for a single message (all other messages are published properly).

Here is the stack trace:

System.NotSupportedException: Stream does not support seeking.
at System.IO.BufferedStream.EnsureCanSeek()
  at System.IO.BufferedStream.get_Position()
  at NATS.Client.Connection.publish(String subject, String reply, Byte[] data, Int32 offset, Int32 count, Boolean flushBuffer)
  at NATS.Client.Connection.Publish(String subject, String reply, Byte[] data)
  at My.Namespace.Infrastructure.Nats.Nats.PublishData(IPublishable dataToSend, String subject, String reply, Boolean flushImmediately) in W:\\_work\\269\\s\\My.Namespace.Infrastructure\\Nats\\Nats.cs:line 70
  at My.Namespace.Infrastructure.Nats.Nats.PublishData(IPublishable dataToSend, String subject, Boolean flushImmediately) in W:\\_work\\269\\s\\My.Namespace.Infrastructure\\Nats\\Nats.cs:line 32
  at My.Namespace.CalculationService.Sequence.SequenceProducer.HandleOnCalculationResult(Object sender, CalculationResultEventArgs args) in W:\\_work\\269\\s\\My.Namespace.CalculationService\\Sequence\\SequenceProducer.cs:line 542
  at My.Namespace.Calculation.Core.SequenceConsumer.ConsumeSequence() in W:\\_work\\269\\s\\My.Namespace.Calculation.Core\\SequenceConsumer.cs:line 163
  at System.Threading.ExecutionContext.RunFromThreadPoolDispatchLoop(Thread threadPoolThread, ExecutionContext executionContext, ContextCallback callback, Object state)
--- End of stack trace from previous location where exception was thrown ---
  at System.Threading.Tasks.Task.ExecuteWithThreadLocal(Task& currentTaskSlot, Thread threadPoolThread)
--- End of stack trace from previous location where exception was thrown ---
  at My.Namespace.Calculation.Core.SequenceConsumer.StartConsumeAsync() in W:\\_work\\269\\s\\My.Namespace.Calculation.Core\\SequenceConsumer.cs:line 136

Environment

• dotnet core 3.1
• nats.net v. 0.10 81aaa2211
• OS: Windows Docker (Server Core 2019) on Windows Server 2019 Datacenter host

[jasper-d]

Great, I’ll deploy it on one of our environments tomorrow. We’ll have decent load over the weekend, but I don’t expect anything anything to break. 😃

[ColinSullivan1]

I’ve built a pre-release containing this fix here: https://www.nuget.org/packages/NATS.Client/0.11.0-pre1

If you could let me know if you run into the issue again, that’d be great. The only difference between v 0.10.1 and the prerelease is this PR, so it’s low risk to use/test in production. There are some other things I’d like to add before the next release.