Explanation
Explanation/Reference: https://cloud.google.com/solutions/correlating-time-series-dataflow

You write a lifecycle management rule in XML and push it to the bucket with gsutil lifecycle set config-xml-file. is not right.
gsutil lifecycle set enables you to set the lifecycle configuration on one or more buckets based on the configuration file provided. However, XML is not a valid supported type for the configuration file.
Ref: https://cloud.google.com/storage/docs/gsutil/commands/lifecycle
Write a script that runs gsutil ls -lr gs://myapp-gcp-ace-logs/** to find and remove items older than 90 days. Repeat this process every morning. is not right.
This manual approach is error-prone, time-consuming and expensive. GCP Cloud Storage provides lifecycle management rules that let you achieve this with minimal effort.
Write a script that runs gsutil ls -l gs://myapp-gcp-ace-logs/** to find and remove items older than 90 days. Schedule the script with cron. is not right.
This manual approach is error-prone, time-consuming and expensive. GCP Cloud Storage provides lifecycle management rules that let you achieve this with minimal effort.
Write a lifecycle management rule in JSON and push it to the bucket with gsutil lifecycle set config-json-file. is the right answer.
You can assign a lifecycle management configuration to a bucket. The configuration contains a set of rules which apply to current and future objects in the bucket. When an object meets the criteria of one of the rules, Cloud Storage automatically performs a specified action on the object. One of the supported actions is to Delete objects. You can set up a lifecycle management to delete objects older than 90 days. gsutil lifecycle set enables you to set the lifecycle configuration on the bucket based on the configuration file. JSON is the only supported type for the configuration file. The config-json-file specified on the command line should be a path to a local file containing the lifecycle configuration JSON document.
Ref: https://cloud.google.com/storage/docs/gsutil/commands/lifecycle
Ref: https://cloud.google.com/storage/docs/lifecycle

https://gtseres.medium.com/using-service-accounts-across-projects-in-gcp-cf9473fef8f0#:~:text=Go%20to%20th

Explanation
Create an instance template for the instances so VMs have same specs. Set the ""Automatic Restart' to on to VM automatically restarts upon crash. Set the ""On-host maintenance' to Migrate VM instance. This will take care of VM during maintenance window. It will migrate VM instance making it highly available Add the instance template to an instance group so instances can be managed.
* onHostMaintenance: Determines the behavior when a maintenance event occurs that might cause your instance to reboot.
* [Default] MIGRATE, which causes Compute Engine to live migrate an instance when there is a maintenance event.
* TERMINATE, which stops an instance instead of migrating it.
* automaticRestart: Determines the behavior when an instance crashes or is stopped by the system.
* [Default] true, so Compute Engine restarts an instance if the instance crashes or is stopped.
* false, so Compute Engine does not restart an instance if the instance crashes or is stopped.
Enabling automatic restart ensures that compute engine instances are automatically restarted when they crash.
And Enabling Migrate VM Instance enables live migrates i.e. compute instances are migrated during system maintenance and remain running during the migration.
Automatic Restart If your instance is set to terminate when there is a maintenance event, or if your instance crashes because of an underlying hardware issue, you can set up Compute Engine to automatically restart the instance by setting the automaticRestart field to true. This setting does not apply if the instance is taken offline through a user action, such as calling sudo shutdown, or during a zone outage.Ref: https://cloud.google.com/compute/docs/instances/setting-instance-scheduling-options#autorestart Enabling the Migrate VM Instance option migrates your instance away from an infrastructure maintenance event, and your instance remains running during the migration. Your instance might experience a short period of decreased performance, although generally, most instances should not notice any difference. This is ideal for instances that require constant uptime and can tolerate a short period of decreased performance.Ref: https://cloud.google.com/compute/docs/instances/setting-instance-scheduling-options#live_mi