* Correct answer is To directly reference one shared and customized log4j2.xml file from multiple Mule applications. Key word to note in the answer is directly.
* By default, CloudHub replaces a Mule application's log4j2.xml file with a CloudHub log4j2.xml file. This specifies the CloudHub appender to write logs to the CloudHub logging service.
* You cannot modify CloudHub log4j2.xml file to add any custom appender. But there is a process in order to achieve this. You need to raise a request on support portal to disable CloudHub provided Mule application log4j2 file.

* Once this is done , Mule application's log4j2.xml file is used which you can use to send/export application logs to other log4j2 appenders, such as a custom logging system MuleSoft does not own any responsibility for lost logging data due to misconfiguration of your own log4j appender if it happens by any chance.

* One more difference between customer-hosted Mule runtimes and CloudHub deployed mule instance is that
- CloudHub system log messages cannot be sent to external log management system without installing custom CH logging configuration through support
- where as Customer-hosted runtime can send system and application log to external log management system MuleSoft Reference:
https://docs.mulesoft.com/runtime-manager/viewing-log-data
https://docs.mulesoft.com/runtime-manager/custom-log-appender

* Organization should continue to use SCM system of their choice, in addition to keeping source code for these asset types in Anypoint Exchange, thereby enabling parallel development, branching.
* Reason is that Anypoint exchange is not full fledged version repositories like GitHub.
* But at same time it is tightly coupled with Mule assets

* If your API implementation involves putting a load balancer in front of your APIkit application, configure the load balancer to redirect URLs that reference the baseUri of the application directly. If the load balancer does not redirect URLs, any calls that reach the load balancer looking for the application do not reach their destination.
* When you receive incoming traffic through the load balancer, the responses will go out the same way. However, traffic that is originating from your instance will not pass through the load balancer. Instead, it is sent directly from the public IP address of your instance out to the Internet. The ELB is not involved in that scenario.
* The question says "each API is deployed to multiple redundant Mule runtimes", that seems to be a hint for self hosted Mule runtime cluster. Set Inbound allowed for the LB, outbound allowed for runtime to request out.
* Hence correct way is to enable communication from each API's Mule Runtimes and Network zone to the load balancer of the other API. Because communication is asynchronous one

Correct answer is Client Management
* Anypoint Platform acts as a client provider by default, but you can also configure external client providers to authorize client applications.
* As an API owner, you can apply an OAuth 2.0 policy to authorize client applications that try to access your API. You need an OAuth 2.0 provider to use an OAuth 2.0 policy.
* You can configure more than one client provider and associate the client providers with different environments. If you configure multiple client providers after you have already created environments, you can associate the new client providers with the environment.
* You should review the existing client configuration before reassigning client providers to avoid any downtime with existing assets or APIs.
* When you delete a client provider from your master organization, the client provider is no longer available in environments that used it.
* Also, assets or APIs that used the client provider can no longer authorize users who want to access them.
-------------------------------------------------------------------------------------------------------------MuleSoft Reference: https://docs.mulesoft.com/access-management/managing-api-clients
https://www.folkstalk.com/2019/11/mulesoft-integration-and-platform.html