Missing Images

[Rob]

There are still missing images since the issues the other day. I have done the obvious checks, clearing cache and the like. It isn’t effecting my mobile view of the forums, I’ve not cleared the cache there yet though, although I suspect a different CSS file may be being used for desktop/mobile usage. The same issue occurred before, from memory I think Sam maybe re-uploaded the images? Not sure why it only seems to affect these two categories?

Screenshots below to demonstrate the issue;

Main Forum Home Page

Unity Category

The same is true of the Unreal category

[Marc_Carlyon]

I had this yesterday but it seems resolved now for me. I dont think i cleared any cache files or anything it just suddenly started working again.
I know this is not a very helpful post in fixing it but at least we know its localised

/uploads/db2322/original/1X/3d83d760283625a8727114567a2e8cc0bd21b515.jpg

This is the image that the forum uses and both display for me.

[Rob]

hmmm, odd, it does seem to fluctuate a bit - only seemed to occur after the downtime the other evening, same happened the previous time also.

The CDN server was not responding along with the main server for the site, or the Discourse server in general (although it may be the same shared platform). What I don’t know is what the infrastructure looks like behind, for example, there may be more than one server dishing out the images on the CDN platform - I could be merely unlucky to be hitting on that has an issue and is not serving these images (for whatever reason, corruption or something) - where-as you may be hitting one that is all good.

All I can re-call is it resolved itself last time the images were re-uploaded, whether that perhaps pushed fresh content to all servers and then changed the reference, which would make sense, but without seeing the bigger picture behind the scenes it’s merely guess work.

I do experience this whether I am logged in or not, and having cleared the cache within both Edge and Firefox can confirm it’s appearing in the same way for Chrome, Edge and Firefox.

@codinghorror may be able to comment on the infrastructure in place perhaps, which may rule out my above craziness

Rings a bell with me as I experienced something similar in my previous work place with DFS shares on a Windows platform, we could publish a .Net application and with the NLB servers, depending which one a user hit they may see the latest or previous version of the application - took us ages to work out what was going on as it was always so seemingly hit and miss.

If there isn’t this level of complication in the infrastructure then it becomes a bit more odd, either the images are missing/reference corrupt and different users are getting different results because of caching, or, something more confusing!

[Marc_Carlyon]

I’m now missing the images for blender and unity lol.
I think its when people are working on the site it doesnt load stuff properly as its random when it happens and to which image (earlier it was just the unity image).
Apologies for my poor typing today btw, CMT is getting the better of my hands today so reduced to two finger typing

[Rob]

I’m now missing the images for blender and unity lol.

…maybe the cache ran out and when it tried to update, nowt was available

Apologies for my poor typing today btw, CMT is getting the better of my hands today so reduced to two finger typing

Hadn’t noticed anything fella, sorry to hear that though, must be incredibly challenging and I’m guessing painful but your perseverance is highly commendable

[Marc_Carlyon]

Thank-you, Some days it does make things a little difficult but i manage. It just means checking and triple checking code before i submit anything.
Pain is relative lol i’ve had this since birth but only recently got a diagnosis so pain tolerance is very high but when it hurts it HURTS!

[Rob]

It just means checking and triple checking code before i submit anything.

Your games and code will be better for it![quote=“irresistiblejelly, post:6, topic:8792”]
but when it hurts it HURTS!
[/quote]

Well it’s awesome that you are here and your username always puts a smile on my face Mr Jelly

[techAPJ]

Hi Rob,

I am Arpit, developer at Discourse.

I am looking into this issue and I don’t think it’s CDN related.

Apart from two images missing on category page are you seeing anymore missing images?

[Rob]

Hi Arpit,

Thanks for checking this out for us.

No, it is only these two images.

The problem occured after the forums were unavailable a couple of days ago. The main Discourse website was also down. I didnt find out if this was planned maintenance or some other issue but having run a tracert it seemed like a fairly significant issue.

Once things came back up these images were missing. We experieneced the same problem previously after an outage. Once they were re-uploaded it seemed to resolve the issue, seems odd its the same images though and that the downtime effected them?

[techAPJ]

I didnt find out if this was planned maintenance or some other issue but having run a tracert it seemed like a fairly significant issue.

Yeah, it was a load balancer issue:

Discourse (discourse)

We experienced the same problem previously after an outage. Once they were re-uploaded it seemed to resolve the issue, seems odd its the same images though and that the downtime effected them?

That is definitely weird. Site being down should not have affected the image availability. I am not seeing anything related to it in /logs as well.

Can you please re-upload those two images. I have taken a backup of your instance at this point of time and will debug the issue on my local dev environment.

[Marc_Carlyon]

I dont know if this information helps but if i right click the failed image and copy the location it will display the image when address is posted into a new browser window.

Hope this helps to identify the issue.

Edit i just scrolled up and noticed that its no longer displaying in this thread either now but it did before!

[Rob]

@techAPJ - thanks for the response, appreciated.

Regarding the load balancing, presumably the content, like the images, are spread across multiple servers also?

Could it be that it just isn’t replicated on the other server(s)? Appreciating it’s probably not on a Windows platform, so thus I wouldn’t have any experience, but I’ve experienced similar issues on a Windows platform, by default previous connections hit the same server, thus meaning the content was always delivered from the same server - only when a new connection was made (potentially like @Marc_Carlyon’s mention of the image being launched in a new browser) was the content returned - but in our case at the time, there was a 50/50 chance of this happening as only two servers were in the scenario.

Regarding re-uploading the images, this did seem to resolve the issue previously - however, oddly, it was the same images that time as it is this time?! Sadly I cannot perform this taks - I am a merely a lowly moderator - @Ben or @sampattuzzi could do this, if they are available etc.

Be nice to get to the bottom of the issue though, as we can’t rule out future load balancing or other issues obviously, so it could present itself again in the future.

Thanks again for your help - it’s appreciated

[ben]

Thanks for this guys, I’ have just re-uploaded the images and it certainly seems to have fixed it (for now).

I’ve set this issue to auto-close in 2 weeks, assuming if it doesn’t happen again in that time it’s fixed.

@techAPJ would be good to understand root-cause however.

[Rob]

When you posted that post @Marc_Carlyon I assumed you were trying to confirm that you couldn’t see the image either, only the little picture icon in the corner with the white line border (the size the image should be) - I didn’t realise you could actually SEE the image correctly when you posted that - as I couldnt’!

That to me suggests that the content (images) are being stored in more than one location and for some users it is being retrieved from one location where it exists, and for other’s not as mentioned in my reply to @techAPJ.

If this is the case, it would be good to know that once the image uploads are done (thanks @Ben, just had a notification popup) we can confirm that the images are in all of the locations necessary on whichever servers they are being stored on. The CDN site was knocked out with the load balancing also when I did the tracert @techAPJ.

[Rob]

I’ have just re-uploaded the images and it certainly seems to have fixed it (for now).

Confirming the same - same behaviour as last time etc.

[Marc_Carlyon]

Just confirm the images are also working again for me.
I posted the link to the image further up in the discussion and it was viable when i posted it but then it vanished.
I also checked the previous image via the URL in a seperate browser window and it loaded there as well but after it disappeared from the thread it gave a 404 error as well.

Both options appear to work on the images now.
Sorry for the sunday spam with issues today Ben all under control now . Enjoy your Sunday