Queries for incorrect MCQs in AEM Exam Prep

[_CL]

Hey guys,

I got the below answers wrong for the practice test in AEM - can you guys please help me with the same?

1.

2.

3.

4.

5.

6.

7.

[MukeshYadav_]

Hi @_CL ,

Regarding question 5- 

In general we do not reduce the time to live for css and js.

Clientlibs are cache more than 1 day or week as they are not changed after deployment.

Versioning of file (filename) and henced url get changed whenever some content (js/css) changed.

Also updated file name will be referenced in pages.

So after deployment once page gets flushed will have updated reference (path)  of cientlib and as it is new path won't be available in cahe and updated css/js will reflect on the page.

You may refer versioning of clientLibs in Aem 6.5 using acs commons or other tool however in AEM cloud it is available by default .

https://medium.com/@satyambansal001/aem-versioned-clientlibs-for-longer-caching-css-and-js-3f189b0f6....

Question 4-

https://helpx.adobe.com/experience-manager/kb/cqbufferedimagecache-consumes-heap-during-asset-upload...

Thanks

[Rohan_Garg · Accepted solution]

Hi @_CL,

Below links should help you with the questions above - 

#1 Turning off asset workflows will not make them ready for use as the rendition generation and other tasks are critical before editors can optimally use the assets. Offloading the assets like its done in AEM Cloud by hosting them on a separate system (Azure, S3, Blob etc) makes more sense.

Apache Sling Discovery allows to coordinate between multiple AEM instances in a cluster.
Sling Discovery helps distribute requests across multiple AEM instances. When an asset request comes in, it can be directed to the least-loaded instance, optimising resource usage. AEM instances can communicate their capabilities (e.g., which instances are optimized for asset handling). This allows for dynamic allocation of asset requests based on the current load or availability of resources.

#2

java.lang.OutOfMemoryError: GC overhead limit exceeded

This message means that for some reason the garbage collector is taking an excessive amount of time (by default 98% of all CPU time of the process) and recovers very little memory in each run (by default 2% of the heap).

This effectively means that your program stops doing any progress and is busy running only the garbage collection at all time. This would require fine-tuning of JVM (https://docs.oracle.com/cd/E13222_01/wls/docs81/perform/JVMTuning.html)
Source - Error java.lang.OutOfMemoryError: GC overhead limit exceeded

#3 Magento or Adobe Commerce acts as the source of truth for all product related information. Any PIM (e.g Hybris) will transfer the product data to Adobe Commerce wherein then it can be accessed by AEM for rendering the experience.

#4 Please refer Issue: Adobe Experience Manager crashes during large asset uploads

#5 Please refer to the below links - 

Versioned Clientlibs for Browser Cache

AEM Versioned ClientLibs — For longer caching CSS and JS

#6 No matter the system fragmentation to store assets, to render the rendition with optimized image it is best to leverage Dynamic Media.

Using Dynamic Media with AEM Assets

#7 100 mil customers implies heavy load, personal and financial data implies can't be cached at CDN which rules out Option B. Having cluster of author and publish instances with only 1 dispatcher is the biggest bottleneck. Adding Load Balancer on top of Dispatcher doesn't help as dispatcher itself is the load balancer for multiple publish instances. This rules out Option C. 

Option A thereby makes the most sense as having 1:1 mapping for each sling instance to dispatcher with a load balancer determining which dispatcher to route the request to thereby optimising the system.

https://experienceleague.adobe.com/en/docs/experience-manager-dispatcher/using/dispatcher

Hope this helps!

Rohan Garg