Exam Professional Cloud Architect topic 1 question 116 discussion

IMHO the correct answer is d) opportunistic mode, not c) proactive mode. The requirement is not to update any running instances. see: https://cloud.google.com/compute/docs/instance-groups/rolling-out-updates-to-managed-instance-groups For automated rolling updates, you must set the mode to proactive. Alternatively, if an automated update is potentially too disruptive, you can choose to perform an opportunistic update. The MIG applies an opportunistic update only when you manually initiate the update on selected instances or when new instances are created. New instances can be created when you or another service, such as an autoscaler, resizes the MIG.

D. Start a new rolling update. Select the Opportunistic update mode.

In Google Cloud, the main difference between proactive and opportunistic updates in a managed instance group (MIG) is when they are applied: Proactive updates: Automatically apply updates to existing VMs. Opportunistic updates: Only apply updates when you manually select a VM to update or when new instances are created. for all those who thinks its C please google and check its a straight forward question and you guyz are confusing people

Option C. To release a non-critical update to your application without updating any running instances and ensuring that new instances created by the managed instance group contain the new update, you should choose option C: Start a new rolling update and select the Proactive update mode. In the Proactive update mode, the managed instance group creates new instances with the updated template while keeping the existing instances running until they are eventually replaced. This allows you to roll out the update gradually without affecting the currently running instances.

D - Correct Managed instance groups support two types of update: Automatic, or proactive, updates Selective, or opportunistic, updates If you want to apply updates automatically, set the type to proactive. Alternatively, if an automated update is potentially too disruptive, you can choose to perform an opportunistic update. The MIG applies an opportunistic update only when you manually initiate the update on selected instances or when new instances are created.

D is correct, per Google's documentation (The MIG applies an opportunistic update only when you manually initiate the update on selected instances or when new instances are created. New instances can be created when you or another service, such as an autoscaler, resizes the MIG.)

D Because the question says: "you don't want to update any running instances. You want any new instances that are created by the managed instance group to contain the new update." For the above case, we chose opportunistic Proactive vs Opportunistic: Proactive: If you want to apply updates automatically, set the type to proactive. Opportunistic: Alternatively, if an automated update is potentially too disruptive, you can choose to perform an opportunistic update. The MIG applies an opportunistic update only when you manually initiate the update on selected instances or when new instances are created. https://cloud.google.com/compute/docs/instance-groups/rolling-out-updates-to-managed-instance-groups#type

Selected answer: D "To prevent any possible impact to the application, you don't want to update any running instances" this is automatic achievable only by using opportunistic applying it during autoscale actions as documentation says: if you want to selectively apply a new configuration only to new or to specific instances in a MIG, see Selectively apply VM configuration updates in a MIG

In my opinion C is correct for Proactive update mode. Considering the following doc; "....Automated updates support up to two instance template versions in your MIG. This means that you can specify two different instance template versions for your group, which is useful for performing canary updates. To start a basic rolling update where the update is applied to all instances in the group, follow the instructions below....." See Also: "Update type Managed instance groups support two types of update: Automatic, or proactive, updates Selective, or opportunistic, updates If you want to apply updates automatically, set the type to proactive." https://cloud.google.com/compute/docs/instance-groups/rolling-out-updates-to-managed-instance-groups#starting_a_basic_rolling_update

https://cloud.google.com/compute/docs/instance-groups/updating-migs#choosing_between_automated_and_selective_updates Automatic (proactive): Use this method if you want the MIG to automatically apply new configurations to all or to a subset of existing VMs in the group. The level of disruption to running VMs depends on the update policy that you configure. You can use this method to canary update new instance templates. To use this method, set the MIG's update type to "proactive". Selective (opportunistic): Use this method if you want to apply the update manually or if you want to update all existing VMs in the group at once. You target any or all VMs to be updated to the latest configuration. To use this method, set the MIG's update type to "opportunistic". Hence, C

It is option C, with proactive update, you are not updating the running instances, you start new ones with the new configuration template. And stop the old ones, so there is not disruption to the service.

To apply an updated configuration to existing VMs, you can set up an automatic update–also known as a proactive update type. The MIG automatically rolls out configuration updates to all or to a subset of the group's VMs. Alternatively, if an automated update is potentially too disruptive, you can choose to perform an opportunistic update. The MIG applies an opportunistic update only when you manually initiate the update on selected instances or when new instances are created. New instances can be created when you or another service, such as an autoscaler, resizes the MIG. https://cloud.google.com/compute/docs/instance-groups/rolling-out-updates-to-managed-instance-groups

https://cloud.google.com/compute/docs/instance-groups/updating-migs#selective_updates no more explications neded

The key here is "you don't want to update any running instances". Only opportunistic support this.

D is correct

Are the people creating these tests retarded? C is correct? how? Correct answer is D

If you want to apply updates automatically, set the type to proactive.