Attempting to demonstrate the need for being able to clear Jetpack’s photon cache.
The above image was accidentally cached in the CDN used by Jetpack’s Photon module.
If you’re unlucky then this is the image you see in the two image slideshow. The images you’re supposed to see in the slideshow are listed below.
- oik-weight-zone-shipping screenshot-1
- oik-weight-zone-shipping-pro screenshot-1
These are the shortcodes used to create the links, images and slideshow.
[nivo id=19798,19803] [bw_csv] [bw_link 19798] [bw_link 19803] [bw_link http://herbmiller.me/wp-content/uploads/2016/07/screenshot-1.jpg] [bw_link http://herbmiller.me/wp-content/uploads/2016/07/screenshot-1-1.jpg] [bw_csv]
With photon enabled the nivo slideshow generates the following HTML. Note the places where
herbmiller.me have been replaced with
<div class="nivoSlider" id="slider-1"><a class="iframe" href="http://herbmiller.me/?attachment_id=19798"><img class="" src="http://i2.wp.com/herbmiller.me/wp-content/uploads/2016/07/screenshot-1.jpg" title="oik-weight-zone-shipping screenshot-1" alt="oik-weight-zone-shipping screenshot-1" data-thumb="http://i2.wp.com/herbmiller.me/wp-content/uploads/2016/07/screenshot-1.jpg" data-recalc-dims="1" /></a><a class="iframe" href="http://herbmiller.me/?attachment_id=19803"><img class="" src="http://i2.wp.com/herbmiller.me/wp-content/uploads/2016/07/screenshot-1-1.jpg" title="oik-weight-zone-shipping-pro screenshot-1" alt="oik-weight-zone-shipping-pro screenshot-1" data-thumb="http://i2.wp.com/herbmiller.me/wp-content/uploads/2016/07/screenshot-1-1.jpg" style="display:none" data-recalc-dims="1" /></a></div>
Steps to create the issue
- Upload the first image ( screenshot-1.jpg )
- Upload the second ( source also screenshot-1.jpg but different folder )
- Create a post with the slide show
- Preview the post which includes the slide show
- Realise the second image was the wrong one
- Delete permanently the second image ( ie screenshot-1-1.jpg )
- Upload the correct image – same name but from a different source directory
- Preview again
- Photon is showing the cached image
- Upload an image with a different name.
- Disable Photon – only works until you re-enable Photon.
- The current situation is that images are cached forever.
- If you want to refresh an image you will need to change the name of the image.
- Adding random query arguments, commonly known as cachebusters, will not work.
- If you want a cached file to be deleted you have to send a request to the Jetpack support team.
Either a tool to clear the cache for a particular image or some mechanism to force an update. I’ve not raised an issue. I’m sure there are more pressing requirements.