Query logs through multiple Azure Application Insights

Question

I'm working on a Azure project which has several Azure functions app. One function app is linked to one Application Insights. So we have as much as functions app as Applications Insights. These functions app will talk between them, and some processes can pass by multiple functions app. On the Azure function, I add logs with a custom EntityID and this EntityID is the same between all function apps.

Now my question is : How I can retrieve all the logs with the same EntityID on all the Applications Insights ?

Like :

traces
| where operation_Name  == "TestLogManagement"
| where customDimensions.EventId == 888 

but on several Applications Insights.

I know that we can regroup multiple Applications Insights by a Tag but no way to retrieve my logs after I created it.

Answer 1

app('app1').traces 
| union app('app2').traces 
| where * contains "42"
| summarize count() by appId 

Please have a look here:

Unify multiple Azure Monitor Application Insights resources

Answer 2

You can also do this in workbooks in azure monitor, so you don't need to encode app names in the query, you can just write the query you want and pick multiple instances of either AI resources or LA workspaces