exceeds_window_size from Mint.HTTP2 when using Mojito.post

[dch]

{:error, %Mojito.Error{message: nil, reason:
  %Mint.HTTPError{module: Mint.HTTP2,
    reason: {:exceeds_window_size, :request, 65536}}}}

I am seeing this bubble up occasionally from Mojito.post (when POSTing to Wordpress); it looks like Mojito needs to renegotiate the window size after initial setup of the connection, or when this error is returned, and then send chunked data over the stream.

• https://github.com/elixir-mint/mint/blob/v1.0.0/lib/mint/http2.ex#L288-L291
• https://hexdocs.pm/mint/Mint.HTTP2.html#get_window_size/2-http-2-flow-control

[jayjun]

One workaround is downgrading to HTTP/1.x. #41

Tesla’s Mint adapter has the same issue. I’ve described why the error happens in detail elixir-tesla/tesla#394. The fix is to receive frames occasionally while sending, which could mean rearchitecting the library.

[gamache]

@dch and @jayjun thank you for documenting this. I can't work on this in the next couple of days but I will look into this.

[gamache]

This is confirmed. A workaround is to force HTTP/1 operation by passing protocols: [:http1] in the Mojito request options.