Clarification on Azure Web App Scale Instance

2019-09-05 08:25发布

问题:

Per article below web app has an option to either auto or manual scale: https://azure.microsoft.com/en-us/documentation/articles/insights-how-to-scale/

Would appreciate if I can get clarification on below:

Scenario: I've ASP.NET Sitecore CMS which uses Lucene behind the scene for search. Lucene index gets rebuilt upon publish of new pages.

Lets say I manually or auto scale to 2 instances:

  1. What exactly happens behind the scene i.e. copies all the website folder to new VM and sets up IIS etc?

  2. Web App has functionality to FTP and view website folders. Is it possible to FTP to both of these instances? From what I know I can only FTP to one of them.

Update:

Problem we are facing:

We use lucene index for our web applications. Looks like the index is built on one web app and not other (website works for some user and not for others). We would like to FTP or RDP and see to make sure this is the case.

Thanks.

回答1:

The FTP or the GIT provided by the Azure is not on the same instance when you use WebApps, So if you do FTP its not to one of the instances - its somewhere else, but when you change files in the FTP or push to GIT, the triggers kick in and a continuous deployment to the Webapp instance/s is done. You can be very well assured that when you upload new files to your FTP that comes with WebApp the build will be updated on both instances. In fact that's one of the driving forces behind webapps that you don't need to think about a VM.



回答2:

We used once Lucene on Web Apps with multiple instances. What we did back then was use Azure Blob Storage to keep the index files, no matter the number of instances, all had the same index information. The only problem was that when new instances would come up (autoscale), they had to load the index on memory and that lead to some cold-starts.

We moved to Azure Search afterwards and never looked back :)