Azure Web App 和 React SSR：初始加载时加载时间极慢

Question

I'm really intrigued by this, I've set up a Node 12 Azure Web App, with server-side rendering in React.

However, I fail to understand why the initial response time is slow (more than 3 minutes), but after this, the response time falls to about 1/2 seconds.

Why is the initial response so slow? I'm new to Azure and SSR web applications, but is the node server just shutting off from inactivity, and starting up the build again every few minutes?

Are there any ways to fix this, apart from scaling the web app up?

Here's the graph on the response time:

Answer 1

The common cause for long application start times is a high number of files in the node_modules. The application tries to load most of these files when starting. By default, on App Service all the files are stored on the.network share (so loading many files can take time).

1.If you haven't done this already, you may try to lazy load your node_modules and not load all of the modules at application start. To Lazy load modules, the call to require('module') should be made when you actually need the module within the function before the first execution of module code. See, if this makes any difference.

2. Kindly check if Always On -Settings/feature is enabled and if it loads as expected.

3. If feasible, enable Local cache (firstly test, and then leverage if required)

Local cache -copies the content from the.network share to the local disk on the VM. Since the files are local, the load time of node_modules is much faster.

Note: Local cache is not supported in function apps or containerized App Service apps, such as in Windows Containers or in App Service on Linux.

4. You may leverage, App Service diagnostic to fetch more details on the issue.