Explanation
Scenario: Users of the ContentUploadService report that they occasionally see HTTP 502 responses on specific pages.
"502 bad gateway" and "503 service unavailable" are common errors in your app hosted in Azure App Service.
Microsoft Azure publicizes each time there is a service interruption or performance degradation.
The az monitor activity-log command manages activity logs.
Note: Troubleshooting can be divided into three distinct tasks, in sequential order:
Observe and monitor application behavior
Collect data
Mitigate the issue
Reference:
https://docs.microsoft.com/en-us/cli/azure/monitor/activity-log

Explanation

Box 1: getContext().getRequest();
Box 2: if(isNaN(i)["tip"] ..
In JavaScript, there are two ways to check if a variable is a number :
isNaN() - Stands for "is Not a Number", if variable is not a number, it return true, else return false.
typeof - If variable is a number, it will returns a string named "number".
Box 3:r.setBody(i);
// update the item that will be created
References:
https://docs.microsoft.com/bs-latn-ba/azure/cosmos-db/how-to-write-stored-procedures-triggers-udfs
https://mkyong.com/javascript/check-if-variable-is-a-number-in-javascript/

Explanation
B: The allkeys-lru policy evict keys by trying to remove the less recently used (LRU) keys first, in order to make space for the new data added. Use the allkeys-lru policy when you expect a power-law distribution in the popularity of your requests, that is, you expect that a subset of elements will be accessed far more often than the rest.
C: volatile-lru: evict keys by trying to remove the less recently used (LRU) keys first, but only among keys that have an expire set, in order to make space for the new data added.
Note: The allkeys-lru policy is more memory efficient since there is no need to set an expire for the key to be evicted under memory pressure.
Reference:
https://redis.io/topics/lru-cache