Launch Async Question

[EyeMed_Don]

During the major issue last Friday (#202312080015), we had some some websites appear to wait on Adobe Launch to load rather than continue in Google Chrome, even though those sites had async in the script tag for Launch in the HTML head.

Since Launch was not available during the issue, the website did not load for minutes until the browser finally timed out the Adobe Launch load.

script src="//assets.adobedtm.com/......../launch-XXXXXX.min.js" async=""

Once the Chrome browser cache was cleared though, the async keyword was respected and the website was able to load immediately while attempting to load Launch in the background.

Did anyone else experience this or have any thoughts on why this may have happened in our implementation?

[Jennifer_Dungan]

Everyone using the Adobe hosting experienced this... the async (the preferred implementation) allowed your other resources to continue loading... (but the site was still stuck in "waiting for resources" waiting for the Adobe files).

Had you not had that, your site would have stopped at loading the JS file and not moved passed (i.e. your site rendering would have halted the site completely, a far worse impact).

The issue was actually an issue with their cloud / content delivery vendor Akamai. All sites using Akamai directly were impacted by this issue much more severely. 

Clearing browser cache would have had nothing to do with you seeing the sites start loading normally... the issue was being worked on actively by both Adobe and Akamai, the most likely scenario is that when you cleared your browser cache you reconnected to a different Akamai server that was functioning...

Nothing you experienced was limited to you... 

While this is a very low risk scenario of happening again (in all my years using Launch, this is the first time I've ever seen this issue - and we were early adopters), it's not impossible...

If you are looking for ways to mitigate this, if you were using "self-hosted" files (i.e. setting up an SFTP host) in Launch, then the issue didn't impact sites the same way, since the files (unless your company uses Akamai) would not be hosted there.

We use self-hosting... I use Adobe hosting for QA/Dev (so those environments were impacted), but Staging and Prod use our self-hosting.

We use the Adobe Publishing Flow to build our Staging/Prod files to our SFTP server, then we have a process to deploy the files from SFTP to our own web server. 

This could be an option you want to pursue if you are concerned. 

[EyeMed_Don]

Thanks Jennifer for the info.

Our issue was some of ours sites did stop loading even though they had async in the Launch script tag.  It appeared specific to Google Chrome and users who had visited the site previously.  We did not see this on Safari or Firefox. Once the Chrome cache was cleared it worked as expected.  I was curios if anyone else in the community saw this as well.

[Jennifer_Dungan]

I experienced the issue on all browsers, even on Chrome incognito... later into the day the issue became more sporadic depending on which cloud server I happened to load.

I think you just happened to get lucky, you were probably checking your sites after the resolution had started rolling out.

Unless you are saying, that some of your sites even with the async attribute were nothing but a white page until you cleared the cache... 

In which case, that would likely have something to do with your sites specifically.

Async just means the JS isn't render blocking... meaning that the resources that come after it can start and finish loading an executing while this file is doing its thing... the whole page won't "finish" loading until all the resources are complete or time-out...

[EyeMed_Don]

"Unless you are saying, that some of your sites even with the async attribute were nothing but a white page until you cleared the cache... "

This is what I was checking to see if anyone else experienced or had any thoughts on why this happened on Chrome.  I agree on all your points on how async works which was why I am at a loss to explain this one.

[Jennifer_Dungan]

That's very strange then.... our affected sites just kept loading... and were very slow, but pretty much the whole site loaded... (except for the Launch file)

It's very strange that your site stopped loading at all... is your site an SPA, or using some special framework that could change the behaviour?

It's good that the issue is fixed, but it does mean that I can't replicate it and try to see what might have been happening...

[EyeMed_Don]

Thanks so much for your all your help.  The impacted sites were SPAs.  This was very strange, and agree I am glad it is now resolved.  We'll look into the actual implementations of these sites on our end. Knowing that no one else appears to have be impacted in this manner is helpful.  Thanks again.

[Jennifer_Dungan]

Well at least not that I saw... but SPAs can do some weird things depending on how they are coded... its possible some sites had a similar behaviour... 

[yuhuisg]

It is unusual that your web pages stopped loading while the browser was trying to load a script asynchronously. Could it be that while your Launch snippet was async, but there was custom code in it that was synchronous?

[EyeMed_Don]

Thank you for the reply.  We have been looking into the website's SPA code as a possible lead on this as well.  

[emcadoret60]

We are experiencing a similar issue. Have you resolved your issue completely?  If so, can you share

[EyeMed_Don · Accepted solution]

Hello, our best theory is that our Single Page Apps with the issue were adding the Launch javascript to the HTML <head> programmatically, rather than just including it in the initial HTML page.  We are updating these Apps to include it in the initial HTML page.  None of our other Apps that included Launch in the initial HTML experienced the issue on our end.

[NimashaJain]

@EyeMed_Don Did you find the suggested solutions helpful? It would be great if you can  mark the answer as correct for posterity. If you have found out solution yourself, share it with wider audience in the community.