Chrome v53 and Firefox v47: Photos/video not loading sometimes (spotty)

[vns2]

Open NCBS25 on chrome. Go to Identity theme - space for biology chapter, for example. Scroll down. Sometimes, the photos will load, if slowly. Switch chapters or themes. Come back to Identity theme - space for biology chapter. Photos and video are not loaded. Sometimes, if it is a slideshow. pressing right arrow or left arrow works to move to second image and get it loaded. But this is not possible for single images. This general problem is there across all themes and chapters.

Similar problem on Firefox. Less so - seems to load 75% of the time.

[salus-sage]

after this release, where chrome (recommended v54) loading has improved, while firefox loading still has problems.

1. Home page featured image breaks some times - weird bug
2. Theme icons in tabs view takes time to load - probable solution to load the image in background before rendering the template. however firefox clears the icon from cache - say for the last or the last but one theme as navigation and media content increases. Solution: increase cache allocation from options.
3. Loading of the images and video thumbnail is quite slower compared to chrome and chromium

[salus-sage]

email by venkat dated 11-11-2016 12:41

However, I faced issues on Firefox. I have attached four images to illustrate what I see (noted by image filenames below). (firefox v 49. I am not putting this as a new issue on github since it's already in progress.)

-- firefox_category-identity: Only in firefox, I see the delay causing the first few seconds of each theme looking like this. This lasts between 4 and 30 seconds. It could be a minor thing, but it strangely only happens in firefox.

-- firefox_page-load-delay1,2,3: I cleared all firefox history, cache, etc, and loaded the exhibit site. image 2 eventually loaded, but it took about 10-12 seconds for that load, section by section. Image 1 and 3 are what I saw when I loaded chapters. The wait time varied from 10 seconds to 45 seconds, to cases where the images didnt load at all. In such a scenario, if I were to restart the page, sometimes the wait time reduced back to 10-45 seconds.

Hope this explanation makes sense!

[salus-sage]

Firefox image loading has lot of browser troubleshooting involved - https://support.mozilla.org/en-US/kb/refresh-firefox-reset-add-ons-and-settings https://support.mozilla.org/en-US/kb/fix-problems-images-not-show

many of the solutions involve changing some default settings in the browser, not sure if we can educate users about such options.

by the the the authorization (htaccess) is completed lot of the requests from network has already resulted with 401 unauthorized

another inconsistency noticed is - Chrome fires the image requests firsts followed by the video requests while firefox requests for videos first and then fires the images resulting in the delay in image loading.

[salus-sage]

Some stats all themes including gallery items In chrome for Identity theme alone including gallery - 99(consistent) requests fired, but firefox is logging 136, 152, 184 requests(inconsistent, double)?

In firefox Institution building 134/108/110 requests chrome 112 requests 9.5mb in 45-57 secs

Growth in chrome 78 requests 11.1 mb in 1.3mins in firefox 234 requests

[salus-sage]

There seems to be a open Bug issue since 2013 regarding firefox performance low compared to chrome with Underscore and Loadash libraries, need to verify if these are related.

https://bugzilla.mozilla.org/show_bug.cgi?id=903970

[salus-sage]

Firefox images are not fetching from cache, cache control headers needs to be fixed on varnish to test.