You will want to refer to the 'Deploy a custom model' documentation for your version. This link is for 10.0: https://doc.sitecore.com/developers/100/sitecore-experience-platform/en/deploy-a-custom-model.html
From the docs, the roles that should be updated are:
All instances of xConnect Collection
All instances of xConnect Collection Search
xConnect Search ...
If you add a file called app_offline.htm into the root of your app service it will effectively take your app service offline and show the contents of that htm file while you are deploying.
If you are using Azure DevOps release pipelines, there is an option to Take App Offline in the Deploy Azure App Service task. This will place the generic default ...
Since Solr is a Java application, you can instrument it using the Application Insights Java Agent, following these steps:
Download the Application Insights Java agent from the official GitHub repository releases page.
Copy the downloaded agent on the Azure VM where your Solr instance is hosted.
Add the -javaagent to your Solr application's JVM arguments, ...
When Sitecore is deployed to Azure PaaS, XM and XP packages for app services contain additional config files for Application Insights in the folder \App_Config\Sitecore\Azure. The file \App_Config\Sitecore\Azure\Sitecore.Cloud.ApplicationInsights.config replaces default log file appenders with Application Insights appenders for standard Sitecore log files.
Got this response from Sitecore Support:
The reported issue is the result of the following error on xConnect CollectionSearch instance:
[Error] Sitecore.XConnect.Operations.XdbSearchOperation`1[Sitecore.XConnect.Contact]: System.NotSupportedException: Contact.Interactions is not currently supported in Azure