Preview

This feature is subject to the "Pre-GA Offerings Terms" in the General Service Terms section of theService Specific Terms. Pre-GA features are available "as is" and might have limited support. For more information, see thelaunch stage descriptions.

VM Extension Manager helps you manage extensions on yourCompute Engine virtual machines (VMs) at scale. Extensions are optionalplugins of theCompute Engine guest agent,which runs on your VMs to provide additional functionality. Google Clouddevelops these extensions to help you monitor and manage your workloads runningon Compute Engine VMs. For more information, see thesupportedextensions.

You can use VM Extension Manager to automate the lifecycle of theseextensions across your entire fleet of VMs, without connecting to each VM. Itinstalls and runs extensions on VMs only when a policy is applied to the VM, andremoves the extensions when you delete the policy. After you install extensions,VM Extension Manager monitors their health status while they arerunning.

To manage extensions, VM Extension Manager communicates with the guestagent on each VM through a secure, standardized communication channel.

VM Extension Manager overview

You can use VM Extension Manager to create policies that declare whichextensions you want to install on VMs. You can also choose VMs that match specific criteria—forexample, VMs with specific labels. These extension policies apply to both existing VMs andany new VMs that match the criteria.

The following diagram illustrates how you can use VM Extension Managerto apply extension policies to VMs based on zones and labels:

As shown in the preceding diagram, you define extension policies within a project. Each policyspecifies extensions to install and a scope, such as VMs in a specific zone orVMs with particular labels. In Zone A,Extension policy E1 targets VMs with theenv=prod label to install the SAP extension, andExtension policy E2 targets VMswithtest=load-test to install both the SAP extension and Ops Agent. In ZoneB,Extension policy E3 targets VMs withenv=prod to install the Ops Agent,andExtension policy E4 targets VMs with no labels to install Workload extension and Ops Agent. VM Extension Manager lets you add, update, or removethese policies and view them at a project level to manage extensions across yourfleet of VMs.

The guest agent on each VM periodically communicates with Google Cloud tocheck for applicable policies. If a VM is targeted by a policy,VM Extension Manager installs the specified extensionsand keeps it up-to-date according to the policy. If no extensions are installed ona VM, the guest agent checks for policy updates every eight minutes; otherwise, itchecks every minute.

Policy priority and conflict resolution

When multiple policies apply to the same VM, VM Extension Manager usespolicy priority to resolve conflicts.

When two policies conflict for the same extension, the policy with the higherpriority takes precedence. Priority values range from 0 to 65535, where a lowernumber signifies a higher priority. The default priority is 1000.If multiple policies have the same priority, the one updated most recently isapplied to the VMs. Deleting a policy does not remove the extension if alower-priority policy still applies to the VM.

VM Extension Manager functions

VM Extension Manager lets you do the following:

• Install extensions at scale: Use policies to install extensions acrosslarge fleets of VMs, instead of connecting to each machine individually.

• Automate extension updates: Configure policies to keep extensionspinned to a specific version, or automatically updated to the latestversion as it becomes available.

  Note: You can pin extensions to a specific version only for the Ops Agent.

• View extension status: See which extensions are installed on each VMwithout logging in to individual machines.

Supported extensions

VM Extension Manager supports installing and managing the following extensions:

Note: For extensions to install successfully on your VMs, you must firstenablethe required APIs in the projectwhere the VMs exist. If you don't enable the required APIs, extensions fail toinstall on your VMs even if you create an extension policy. The following tablelists the service APIs required for each extension.

Extension	Description	Required APIs
Ops Agent	Installs theOps Agent, which collects logs and metrics from your Compute Engine instances, so that you can view these telemetry on Google Cloud Observability dashboards.	Cloud Monitoring API Cloud Logging API
Extension for SAP	InstallsGoogle Cloud's Agent for SAP, which is required for SAP systems running on Google Cloud. The agent collects SAP Host Agent metrics, Process Monitoring metrics, and Workload Manager evaluation metrics.	Workload Manager API
Extension for Compute Workload	InstallsAgent for Compute Workloads, which you can configure to collect metrics from multiple workloads running on Compute Engine instances.	Workload Manager API

Supported operating systems

Note: Support for SUSE Linux Enterprise Server (SLES) and Ubuntu operatingsystems is not available.

VM Extension Manager supports installing extensions on any operatingsystem that is supported by the specific extension. For details aboutsupported operating systems for each extension, see the following:

• Ops Agent:Supported operating systems
• Extension for SAP:Supported operating systems
• Extension for Compute Workloads:Supported operating systems

Limitations

VM Extension Manager supports project-level rollout.

Quotas

Each Google Cloud project has a limit of 100 VM extension policies per zone.There is no limit on the number of VMs you can select per policy.

Pricing

There is no charge for using VM Extension Manager. However, you mightincur charges from using the extensions installed by the policies. For moreinformation, see the pricing pages for the specific extensions:

• Ops Agent pricing
• Extension for SAP pricing
• Extension for Compute Workloads pricing

What's next

To learn more about managing extensions, see the following resources:

• Install VM extensions by creating extension policies
• Manage VM extensions by using extension policies