js-libp2p@0.37.3 does not support chunks bigger than 2Mb anymore

[alxroyer]

• Version: js-libp2p@0.37.3 (vs js-libp2p@0.36.2)
• Platform: Windows + node v16.13.2
• Subsystem: @libp2p/mplex? (to be confirmed)

Severity:

Low

Description:

When receiving chunks of data bigger than 2Mb from a stream, Error: message size too large! errors are raised,
while with js-libp2p@0.36.2, we could exchange chunks of 10Mb at least.

Not really an operational problem I guess. Quick workarounds easy to set up.
But depending on the root cause, I can't say on my own whether that problem could hide a bigger one.

Steps to reproduce the error:

Using the scripts attached with #1342, launch the sender (3145728 = 3 * 1024 * 1024):

node libp2p-node.0.37.x.mjs --send=path-to-a-big-file --size=3145728

then launch the receiver:

node libp2p-node.0.37.x.mjs --connect=/address/of/sender/node

Error displayed by the receiver:

file:///.../node_modules/@libp2p/mplex/dist/src/restrict-size.js:14
            throw Object.assign(new Error('message size too large!'), { code: 'ERR_MSG_TOO_BIG' });
                                ^

Error: message size too large!
    at checkSize (file:///.../node_modules/@libp2p/mplex/dist/src/restrict-size.js:14:33)
    at Array.forEach (<anonymous>)
    at restrictSize (file:///.../node_modules/@libp2p/mplex/dist/src/restrict-size.js:21:25)
    at processTicksAndRejections (node:internal/process/task_queues:96:5)
    at async file:///.../node_modules/@libp2p/mplex/dist/src/mplex.js:134:38
    at async MplexStreamMuxer.sink (file:///.../node_modules/@libp2p/mplex/dist/src/mplex.js:133:17) {
  code: 'ERR_MSG_TOO_BIG'
}

[alxroyer]

For the info, I came up through this while measuring the impact of chunk sizes on transfer rates, which gave me the graph below:

We can see on this graph that orange dots (js-libp2p@0.37.3) stop at 2Mb, while blue dots go up to 10Mb.

[mpetrunic]

You scripts are initializing Mplex with default max message size value, you should set it to something higher:
https://github.com/libp2p/js-libp2p-mplex/blob/v1.1.2/src/index.ts#L11

[mpetrunic]

@Alexis-ROYER

[alxroyer]

Thanks for the info @mpetrunic.

To compare with the Mplex coming along with js-libp2p@0.36.2 (libp2p-mplex@0.10.7 on my side):

• I guess it means that the default max message size was different?
• Or possibly this max message size limit did not exist?

[mpetrunic]

Not sure honestly. maybe something was overriding that limit