libp2p/js-libp2p-spdy

go-libp2p-spdy has problems - Can not send objects to go, if they are larger than 64k

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#48 opened on Dec 23, 2016

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Description

I've been tracking this issue for some time now, and it looks like this is due to spdystream (go implementation of spdy being used) not support flow control.

But lets start from the beginning.

  1. Sending files from js to go ipfs works fine for files less than 63k, but starts suddenly failing at anything larger.
  2. Looking into the logs, go-ipfs bitswap never receives the block we are sending
  3. Looking into spdy it turns out it never emits the message we sent to the layer above.
  4. It turns out the INITIAL_FLOW_CONTROL_WINDOW_SIZE is set at 64k, which spdy-stream (js impl) follows. But with larger buffers it starts using the flow control features of spdy.
  5. It turns out there is an open issue to support flow control on spdystream, and as it does not implement it is not able to handle the frames spdy-transport is sending. https://github.com/docker/spdystream/issues/2

Contributor guide

Research direction
Investigate the flow control issue between js libp2p spdy and go spdystream. The go library does not support SPDY flow control, causing large messages to be dropped. Consider either contributing flow control support to the go spdystream library or implementing a workaround in js libp2p spdy to limit message size or handle window updates.
Tech stack
javascript
Domain
networking
Issue type
Bug
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
4
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
1-2 days
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
Active
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
Clear
Prerequisites
SPDY protocolnetworking
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
40