Azure App Service scaling too slow

Question

When I try to scale my Azure Web App, I experience very slow response time for requests in the second or third instance of the application. It looks like the other instances were in cold mode and had to switch to hot mode as soon as the load balancer redirected the request to them.

The problem is that in my scenario, most of the time in the system is not so much, so probably only one instance will be used through the load balancer, but there is a peak about four times a day, and I need more than one instance. But if these cases are cold and should have woken up first, it actually makes the situation worse.

The question is what to do?

I have already installed the application "always on" and "Affinity ARR" to "off".

In the past, I already had problems connecting my application to some kind of sleep mode, even if the application was set to always on. I solved this by setting up a scheduler task that calls the application every hour. But I don’t think this will work with multiple instances anymore, because the task will only call one instance, and the other instances will still be in sleep mode.

Any suggestions?

Answer 1

Consider debugging logging which instances receive requests and why these requests are slow.

For comments about four times a day, you need more than one instance of the instance — consider setting up Autoscaling with a repeat profile in terms of application maintenance to scale automatically. You can set an autoscale rule with different instance values ​​depending on the time of day.