Troubleshooting downtime (potentially autoscaling-related) issues - causes 500

[Rainulf Pineda]

Hi,

We've been having downtime issues this past few months -- typically happen within few secs before it goes back up.

I suspect the cause of it is autoscale (looking at their start times) -- error 500 on the gateway.

Troubleshooting: I don't know what criteria app engine decides to autoscale (or kill instances) - is there any way to figure this out from the logs? Some sort of event log saying "CPU usage reached 30%, autoscaling to 3"?

Thanks!

[Goran (Google Cloud Platform Support)]

Hello,

App Engine scales instances up when the volume of incoming requests increases and scales instances down when this volume decreases. This scaling helps ensure that all of your application's current instances are being used to optimal efficiency and cost effectiveness. For more information please see the documentation for scaling dynamic instances [1].

You can use several settings in the application configuration file to adjust the trade-off between performance and resource load. For the list of the available auto-scaling parameters, please see ‘Using performance settings’ section of this article [2].

A good recommendation is to benchmark performance with default scaling settings then run a new benchmark after each change. See this article[2] for some best practices to ensure that your app will scale efficiently to the volume of incoming requests.

[1] https://cloud.google.com/appengine/docs/standard/python/how-instances-are-managed#scaling_dynamic_instances

[2] https://cloud.google.com/appengine/articles/scalability

[Rainulf Pineda]

Goran,

Thank you for your reply! I understand that App Engine scales up and down depending on certain criteria -- whether that's incoming requests, CPU usage, and more. 

But that is not my question. My question is if there's a way to determine its decision whenever it kills or create instances. A log such as this would be helpful: "incoming requests has decreased from 1000 to 10, therefore, killing 10 out of 50 running instances"

[руслан мирзиеев]

Выйдете со мной на связь

пт, 15 февр. 2019 г. в 03:56, Rainulf Pineda <rainu...@gmail.com>:

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