Refer to this guide to learn How to Create Managed Instance groups in GCP\
<https://scribehow.com/shared/Creating_Managed_Instance_Groups_MIG_V2__mWRHPJ00SfeQJdH06V6cCQ>

Refer to this guide to Explore Managed Instance Groups in GCP<https://scribehow.com/shared/Playing_with_Managed_Instance_Groups_MIG__SLIdTLX5RgWrMiFbtzesOg>

Sign in into the **Google Cloud Platform**

Type "**Compute Engine**" in the search bar and click on the **Compute Engine** option

**What is a Compute Engine?**

Google Compute Engine (GCE) is an Infrastructure-as-a-Service (IaaS) offering from Google Cloud Platform (GCP) that allows users to run virtual machines (VMs) on Google's infrastructure. It provides scalable and flexible computing resources, high-performance persistent storage, advanced networking capabilities, and integration with other GCP services, making it suitable for a variety of workloads including web hosting, data processing, and high-performance computing.

Click on the **Instance groups** from the left bar

**What are Instance groups?**\
\
Instance groups in GCP are sets of virtual machine instances managed together for load balancing and scaling. They distribute traffic evenly across instances, automatically adjust capacity based on demand, and ensure high availability by spreading instances across multiple zones.

**Instance groups** wizard will open, click on the **my-managed-instance-group**

To **update VMS**, click on the **UPDATE VMS** button on the top left side

**What is UPDATE VMS?**\
\
"UPDATE VMs" refers to the process of applying changes to the virtual machines (VMs) in a managed instance group. This can include tasks such as updating software, applying security patches, changing configurations, or upgrading to a new VM template. In GCP, this process is often managed through rolling updates, which update VMs gradually to ensure minimal disruption and maintain availability.

**Update VMs in my-managed-instance-group** wizard will open, scroll to the **New template** section, here you can modify the instance template and select different available instance templates from the dropdown

**Note:** These instance templates should already be created before modifying the instance groups.

On the **New template** section, click on the **ADD A SECOND TEMPLATE** button to add a second template for the Instance groups

Scroll to the **Edit type** section, here you can choose between **Selective** and **Automatic** for the type of the instance group

**What is the Selective Edit type?**\
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Selective Edit type in GCP allows you to update only specific instances or settings within a managed instance group, rather than applying changes to all instances simultaneously.

**What is the Automatic Edit type?**\
\
The Automatic Edit type in GCP refers to applying updates or changes automatically to all instances within a managed instance group. This method ensures that all instances are consistently updated without manual intervention.

If you choose the **Automatic** type, you can select the actions allowed to update VMs

Scroll to the **Temporary additional instances** section, here you can modify the Temporary additional instances for the Instance group

**What are the Temporary additional instances?**\
\
**Temporary additional instances** in GCP refer to extra VM instances that are created temporarily during the update or maintenance of a managed instance group. These additional instances help ensure continuous availability and minimize service disruption by handling traffic while existing instances are being updated or replaced. Once the update process is completed, these temporary instances are automatically removed, returning the instance group to its original size.

Scroll to the **Maximum unavaialable instances** section, here you can modify the Maximum unavailable instance for the Instance group

**What are the Maximum unavialable instances?**\
\
**Maximum unavailable instances** is a setting in GCP that specifies the maximum number or percentage of VM instances in a managed instance group that can be taken offline simultaneously during updates or maintenance. This ensures that a certain number of instances remain available to handle traffic, maintaining service availability and reducing the risk of downtime. The setting helps balance the need for updates with the need to keep the application running smoothly.

Scroll the page and click on the **UPDATE VMS** button to apply the changes

Congratulations! You have successfully Updated VMS

Google Cloud

This guide provides step-by-step instructions for updating a Managed Instance Group (MIG) using Rolling Updates V2.

Updating a Managed Instance Groups (MIG) - Rolling Updates V2