There is a cost for doing so as instances kept running in this way do incur billing costs [1].
I've done some work with Ruby in the past, and based on my experience, you might not be able to take advantage of Cloud Run's best feature, concurrency[2], which is another way to reduce cold starts by routing concurrent requests to the same container instance. Ruby maybe blocking in flight requests and forcing us to fire up another instance to handle it. Once the first request has completed there is a chance the container instance processing that request will be spun down, this is something minimum instances can help with. You might need more than one minimum instance to compensate for the lack of concurrency if you really want to see improvement in overall latency.
[1] https://cloud.google.com/run/docs/configuring/min-instances
Consider checking the following: - Number of CPUs. The number of CPUs is not CPU cores but Kubernetes millicores. 1 vCPU on CR = 400m (4/10 of a CPU core). - Background processes - not recommended [https://stackoverflow.com/questions/61154349/google-cloud-ru...] - Container size on disk. Google Cloud is fast. However they need to cap the moving container images around as they can't use all the network capacity for moving a 400MB Docker image. If you're not already, use multi-stage builds with tiny final images.
> Limits and requests for CPU resources are measured in cpu units. One cpu, in Kubernetes, is equivalent to 1 vCPU/Core for cloud providers and 1 hyperthread on bare-metal Intel processors.
(code is here BTW https://github.com/futurice/terraform-examples/tree/master/g...)
However you can set the minimum instance count now. That feature was opened up for Cloud Run managed a few weeks ago.
I wouldn’t call JVM application servers legacy. If you are referring to WebSphere and Weblogic, then maybe. But the open source JVM application servers like tomcat,jetty, netty etc., are widely used in modern applications
AppEngine has been around for a long time, 12 years to be exact, and in my mind it's a completely different product, and still one of our most successful. While Cloud Run competes with AppEngine on some fronts, customers really appreciate AppEngine's deep integration with other GCP managed services. It's a full blown PaaS.
I expect Cloud Run to improve over time and gain more features that will no doubt match the requirements of many AppEngine customers, some may switch to Cloud Run, but we are not forcing them to.
Cloud Functions already shares a lot of underlying infrastructure with Cloud Run, which shares a lot of underlying infrastructure with AppEngine, and that's by design. These days I like to think of Cloud Functions as a simplified developer experience on top of Cloud Run focused on task orientated workloads backed by events and triggers.
Can we continue to support 3 somewhat overlapping Serverless platforms going forward? I believe the answer is yes, thanks to the shared infrastructure, and the fact we truly believe all three platforms offer a unique set of developer experiences worth preserving. Maybe there is future state where one product satisfies all use cases, but that's not today, so we plan to keep listening to customers, and invest across the board.
One recent example of investing across the board: you can now leverage global load balancing[1] across all three Serverless platforms.
[1] https://cloud.google.com/load-balancing/docs/negs/serverless...
Though I will say I dearly miss the days of first generation GAE standard, when things like memcache, taskqeue, datastore, auth and logging were all baked in as first-class citizens and Just Worked™.