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Site slower after switching to HTTP2 - Printable Version

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Site slower after switching to HTTP2 - etsvilik - 02-16-2019 02:35 AM

Hi ,

Site is https://www.czarfloors.com
Our hosting recently switched our site to newer IIS10 with support for HTTP/2
Performance suffered as a result. All images now showing simultaneously on one connection but much slower load times. Hosting assured us that there is no bandwidth limit and raised number of concurrent connections to 100. . What gives?
Test results before switch:

Before swicth to http2

Now showing this result :After http/2

RE: Site slower after switching to HTTP2 - pmeenan - 02-18-2019 02:11 AM

That's how the HTTP/2 protocol works. The browser requests everything as soon as it knows about it and provides some priority information with each request and the server delivers them in priority order. Lower priority resources will take longer to respond because they are queued behind the higher-priority resources.

You can't look at the timing of individual requests unless there is nothing else going on on the connection at the time.

The actual site loading performance seems to have gotten better: https://www.webpagetest.org/video/compare.php?tests=190209_G2_e9674a98de574cfbcdc75c3b8b5e106b-l%3ABefore%2C190213_Z4_9d994f1f5a3c4fddbdfaaabd999fca2e-l%3AAfter&thumbSize=200&ival=100&end=visual

RE: Site slower after switching to HTTP2 - etsvilik - 02-18-2019 06:57 AM

Thank you for looking into this. I had some further optimization done on site.
Still, "great promise" of keep alive is not working for this site. The end result is that site is visually complete later than before. On another site I had converted the improvements were very apparent. Same hosting service. It tells me that hosting is not a problem but actual site composition/design and looking for suggestions. Can you see anything apparent bottleneck in the tests? I noticed huge difference in CPU busy time but can't explain it.
I had another disappointment truing CloudFront CDN to serve all images. I saw practically no improvement.