Gzip compression error

[lewispham]

I've tried testing spdy with gzipped content. Unfortunately, instead of ungzipping it, Chrome throws the error net::ERR_SPDY_COMPRESSION_ERROR.

spdy.createServer(options, function(req, res) {
  var stream = res.push('/main.js', {
    request: {
      accept: '*/*'
    },
    response: {
      'content-type': 'application/javascript',
      'content-encoding' : 'gzip',
    }
  });
  stream.on('error', function() {
  });
  stream.end(zlib.gzipSync('alert("hello from push stream!");'));

  res.end('<script src="/main.js"></script>');
}).listen(3000);

[akyoto]

Same here :+1:

Also: If the push stream itself does not use gzip but the actual response does I get the error as well.

[indutny]

What version of node-spdy are you using? May I ask you to run the script with DEBUG="spdy*" and gist the results?

I have just tried it in chrome and it appears to be working with the latest spdy.

[lewispham]

@indutny I'm using node-spdy v2.1.0 (checked via npm list). Could you give me a detailed instruction? I'm not really familiar with gist.

[akyoto]

spdy 2.1.0 output (single get request): https://gist.github.com/blitzprog/374be5e587b6a595ede2

Relevant test code:

if(response.push && request.url === '/') {
    let push = response.push('/images/backgrounds/keyboard.jpg', {
        request: {
            accept: '*/*'
        },
        response: {
            'Content-Type': 'image/jpeg'
        }
    })
    push.end(require('fs').readFileSync('/home/eduard/projects/blitzprog.org/images/backgrounds/keyboard.jpg'))
}

Note that I do not gzip the push itself. However the actual HTML response is gzipped. If I do gzip the push the error stays.

You need to emulate a higher network latency to even see the error message on localhost because it quickly disappears.

Chrome version is 48.0.2560.0 dev (64-bit) on Ubuntu 15.10 however I get the exact same error on v46 (stable).

[indutny]

@blitzprog is this gist from the error-ed case? I can't see anything abnormal or any kind of error in it.

[akyoto]

@indutny: It is, however the error appears in Chrome only and I don't know whose mistake it is. I looked up the error code (ERR_SPDY_COMPRESSION_ERROR) in Google and the threads were saying that this is an nginx issue (read: mistake of the webserver). Therefore I assume(d) it could be a bug in node-spdy.

I don't really know whose fault it is. I just want it to work :/

Do you need more details?

[indutny]

@blitzprog ok, if this is happening on the Chrome side - let's try to figure it out from that side! :)

May I ask you to open chrome://net-internals/ before the test, start spdy server, make a faulty request that results in compression error, and click export at chrome://net-internals/ tab?

If you want to send this data using private channel - my email is public on my github profile.

Thank you very much, Fedor.

[akyoto]

@indutny Sent you the exported data via mail, let me know if you need anything else.

[indutny]

Thank you, this is a relevant error from chrome's log:

t=746 [st=743]    HTTP2_SESSION_CLOSE
                  --> description = "Framer error: 5 (DECOMPRESS_FAILURE)."
                  --> net_error = -363 (ERR_SPDY_COMPRESSION_ERROR)

Going to dig into it.

[indutny]

Wow, 14 days. Sorry for delay. Still looking into it.

[indutny]

I think it should be fixed wit the latest spdy-transport@2.0.3 . Please run npm update and give it another try. Sorry again for the long wait!

[jadbox]

Can we get an example of spdy+gzip? (non-push)

[indutny]

@jadbox I think the code here is quite relevant to your question, but anyway I don't think that this question really belongs to this issue. Feel free to open another issue if you want to discuss this, though!

[lewispham]

I still got a gzip compression error (on Chrome) with the sample code taken from issue #237 . Despite the Content-Encoding: gzip header is already added, it seems that gizpped files transfered via PUSH_PROMISE are not ungzipped on Chrome. Here is the content of main.js. Similar result with main.css.

[indutny]

@tresdin asking just in case, you are piping files straight to the push stream. Are the files themselves compressed with gzip?

[lewispham]

@indutny

you are piping files straight to the push stream

Yes. You can see it from the sample code.

Are the files themselves compressed with gzip?

Yes. These files are compressed by the built in node zlib gzip compression

[lewispham]

@indutny Should I open another issue for this bug?

[indutny]

@tresdin heya! Sorry for delaying. Going to look at this right now.

[indutny]

Sorry, but it looks like an issue in your code. First of all, you are using deflateSync and then advertising gzip compression. You should consider using deflate instead, or compress it according to the header.

The second thing is the way headers are pushed to the browser. It should be something like:

var stream = res.push({
  response: {
    'Content-Encoding': 'deflate'
  }
});

Hope this helps!

[lewispham]

@indutny It doesn't help me. I'm using zlib.gzip for compressions. And the sample code is actually taken from #237 .

[indutny]

@tresdin I'm afraid that that code is broken. May I ask you to apply suggest changes, and repost the code sample here?

[lewispham]

@indutny Retested with this sample code. And browser produced the same error.

spdy.createServer(options, function(req, res) {
   // main.js and main.css were recompressed with `zlib.deflate`
    ['/app/main.js','/app/main.css','/app/favicon-32x32.png'].forEach(function(url){
        console.log('fetching',url);
      var stream = res.push(url, {
          'content-type': `${MIME[url.substr(url.lastIndexOf('.')+1)]};charset=utf-8`,
          'content-encoding' : 'deflate',
        });
      stream.on('error', function(er) {
          //throw er;
      });
      var fstream = fs.createReadStream('/home'+url);
      fstream.pipe(stream);
    });

  res.end(`
    <!DOCTYPE html>
    <html>
        <head>
            <script src="/app/main.js" async></script>
            <link rel="stylesheet" href="/app/main.css" async>
            <link rel="icon" type="image/png" href="/app/favicon-32x32.png" sizes="32x32" async>
            <meta name="viewport" content="width=device-width, initial-scale=1">
        </head>
        <body></body>
    </html>`
  );

[indutny]

You need to put headers in a following way:

res.push(url, {
  response: {
    // your headers
  }
});

It should work after this change.

[lewispham]

@indutny You're right. It works now. I forgot that change. Thank you.