Doesn't seem to perform compression when running on Windows.

We have a really odd issue. We’re using the standard configuration, and making requests to the server, everything looks correct even up to the point we flush the request, but for some reason, the output is not compressed and the headers are missing on Windows.

Oddly, if we run the exact same code on Linux, the output is compressed.

We’re not using a proxy or anything.

Here’s our output of getHeaders at the end of our response:

content-encoding:"gzip"
content-type:"application/json; charset=utf-8"
etag:"W/"1e928-ejrkE6/bCZuNbsnF8HFNVEAq/EU""
vary:"Accept-Encoding"

Here’s what the browser is showing (and no, the size is not showing the compressed size):

You can see the eTag is the same.
No idea what’s going on here - any help would be appreciated.

[dougwilson]

Well, I would suggest the next step is to install Wireshark and get a packet capture of the packets coming from the Node.js server to verify if that is compressed or not. If it is, you have something tampering with your traffic somewhere.

[dougwilson]

Are you sure you don’t have some sort of WAF installed on the machine that is silently uncompressing responses? Perhaps, does this happen for requests over HTTPS vs over HTTP? If it only happens on HTTP, it would seem to point to somethig on your machine is hijacking your traffic at some point, since a HTTPS request is encrypted to the web browser.

I’ve seen a few people report no compressing here and it turned out to be an anti virus or other scanning software that embeds into your network stack.