I'm developing a Magento2 website, everything is running well for now, except a random issue I can't figure out how to solve.
The website is using Varnish, and all pages have a varnish cache HIT, with a very low TTFB about 30ms and low content download too (about 40ms)
But randomly, the download timing increases to more than 2 seconds, and on the next page visit it will go down to normal 40ms.
Same issue on all browsers, so not a browser issue.
Would someone have an idea ?
Many thanks
There are so many factors at play. The most important thing is whether or not you can simulate the issue and predict when the issue will appear again.
Once you're able to simulate, you need to determine what type of resource is slow:
Is it the graphical rendering of the page in the browser?
Is there a 3rd party JS resource that is slow?
Is it the actual TTFB of the main page that is slow for that resource?
Please use your browser's development tools and check the breakdown in the networking tab. With enough attempts, you'll be able to spot the issue. When you do, please add a screenshot of the breakdown in this question.
In parallel, you can keep the following command running to identify requests that took more than 2 seconds to process:
varnishlog -g request -q "Timestamp:Resp[2] > 2.0"
You can also add the output to your question.
Related
I'm testing a woocommerce website which should go online next week. I'm facing serious problems regarding the load time. Seems that the initial load time is really really slow slow (about 20sec). When activating the coming soon mode all seems normal.
18 sec go to waiting for the page being able to be displayed. I've already tried disabeling all plugins but that doesn't help.
Any ideas? I'm getting quite desperate :-)
link to pingdom speed test
link to gt metrix speed test
I'm looking at a waterfall in Chromes Developer tools of several CSS and Javascript files.
When refreshing the page, several of the files load from the browser cache, as expected. These are taking 1ms to load most of the time. However some files, and it seems to be the same offenders each refresh, are taking quite a bit longer. Sometthing between 400ms and 800ms.
The waterfall timeline in Chromes network tab shows that this time is spent in the TTFB (time to first byte) in some cases. This doesn't make any sense to me, if it's getting it from the browser cache it should be getting it from the hard drive, not the server, why is there a TTFB?
For other files or sometimes on a different refresh I see the time is blamed on content dowloaded time. Again, coming from cache this should be pretty instantaneous, yet I'm seeing it take over half a second sometimes.
Can anyone shed some light on what's happening here?
This is a web app I'm working on so I don't have a link I can share I'm afraid.
We have a website that a few people are complaining about it running extremely slow. We're struggling to figure out why and to even recreate it. Most are mentioning that it's running slow in IE.
It's not limited to any specific section of the site, just the whole thing in general.
There's been several developers creating/adjusting the code so it's overly bloated but we can't see any specific reason why this should happen.
Can anyone see why?
We've also run a speed test:
I was running a profiling test with IE on your website and there is a call to:
http://www.playforce.co.uk/-ms-transform.htc
Which is giving error 404 not found and taking 1 second to complete (0.91 sec).
If is found all around your css under this line:
behavior:url(-ms-transform.htc);
Am no expert !! Am welcome to better suggestion and corrections of what i am about to say
You can try using a trial version of Borland Silk meter ..
They tend to measure the speed with which each element loads using various browsers and various geographical locations which are configurable by you.
Also , since only some of the user's are complaining about the speed being an issue you should also check the speed of their internet and their browser version and other addon etc of those users. Because sometimes the problem is not only with the server .
Try the above tool to confirm nothing is wrong in your server and then proceed to checking the client's browser and network.
I've been building a site, running Wordpress 3.2.1 and noticed
the performance is sluggish in the front and back end.
I believe the problem is hosting specific.
The problem seems to be the connection loading the actual HTML
which is taking about 5.5 seconds. It appears to finish after
about 500ms, but does not stop loading for 3-4 more seconds.
Here is the development URL:
http://d1001488.u57.ukisp.com/dev/
Hosting:
Windows NT
PHP Version 5.2.10
There are a couple of jQuery select boxes that get
replaced and styled onload (in the footer), these take a
long time to get replaced after the page fully loads.
The hosts are claiming all is running properly. Is there
any thing I can try and tweak or monitor to see what
is going on? Or any suggestions?
Thanks.
For largely extrinsic causes, try YSlow. This will identify a number of things you can work on. It won't tell you anything about the internal behavior of your server, but it may help you narrow down what's going on.
The problem may be a specific plugin. Here's what I would recommend:
Try going through each plugin, deactivating it, and see if that makes your site load faster. Do this for each plugin, and if a deactivated plugin doesn't improve performance then just reactivate it and move to the next one.
Try temporarily activating the default Twenty Eleven theme. See if the default theme loads faster. If it does, then we can look at your custom theme.
These two things may help narrow down at least where the problem is coming from. Let me know how it goes!
Do you have CPanel access with your hosting account? If you do, look in the left side toolbar at the bottom you should see where it says server status (click to view) you will see various details about your server performance.
We are performance tuning our web site at the moment and have the main page content down to a respectable 65ms for firefox to grab it (from request to finish receiving the html).
Caching means there is generally no other content that needs to be requested from the server (after the initial page view).
However, firefox is spending another 400ms until onload fires. I assume this is the time it takes firefox to parse our html, fetch images, css and js from the cache, parse the css and js and render the page.
So, my question is, how can I drill into this 400ms of dead time and find out where most of it is being spent? eg. if I knew that css parsing was taking a long time, I could review that and turn it up as needed.
I don't really have any tools with enough sophistication for doing this. Any suggestions?
UPDATE: I know when the resources (like images etc) are loading. It is the other time, after the resources load I am trying to look at. YSlow don't help with this area.
Firebug with the YSlow add-on are great tools for seeing what resources are taking the longest to load.
In addition to firebug and yslow mentioned by Tim S Van Haren, there's also Page speed by google, also a firebug add-on.
Edit: Crockford recommends in his talks about javascript to use Dynatrace for IE, or the developers tools in chrome. Apparently, Firefox doesn't have the extensions for that level of precision yet, but it may have changed since the talk
And there's also this previous thread on Stackoverflow
You may want to give Fiddler a try. You can watch the HTTP traffic from several browsers and see a page's resources' load times.