Sending data frame followed by trailer frame discards the data frame

[ohadvano]

Sending data frame followed by trailer frame discards the data frame

[Darksonn]

This is extremely unlikely to be a bug in the mpsc channel, so this is probably the wrong place to report this.

My initial guess is that without the sleep, both frames are sent together in a single packet?

[ohadvano]

I am not too familiar with the internal implementation of either tokio or tonic, but my assumption was that since I first send Ok, then Err to the channel, the internal impl may discard previous messages since it now sees that an error occurred.

My initial guess is that without the sleep, both frames are sent together in a single packet?

Without the sleep, there is no DATA frame sent, as shown in the picture above. Only the HEADERS frame is sent.
It seems like that if I add the sleep, then there's enough time for the first message to be actually flushed to the wire, so it's not lost.

[Darksonn]

That assumption is wrong. The mpsc channel never discards messages.