Intermittent stall and failure

[Quantumplation]

Hello,

When requesting many dynamodb items in parallel (in my case, 50) through the DAX client, the DAX client seemingly deadlocks and ultimately fails with the following error:

UnknownError: unknown error
caused by: file already closed

I did some initial investigation, and it appears this error is thrown here:

aws-dax-go/dax/internal/client/tubepool.go

Line 123 in cb4d531

return nil, os.ErrClosed

My hypothesis is that there is a deadlock, the tubepool gets closed because of some kind of idle check, and then the deadlock times out and fails on this error; but I'm not familiar enough with the code base to investigate further.

[Quantumplation]

This behavior appears to disappear somewhere between 8 and 16 requests, but that might just be because it comes rarer and rarer.