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Supported features using Istio APIs (managed control plane)
This page describes the supported features and limitations for Cloud Service Mesh using TRAFFIC_DIRECTOR or ISTIOD as the control plane and the differences between each implementation. Note that these are not options you can choose. The ISTIOD implementation is only available for existing users. New installations use the TRAFFIC_DIRECTOR implementation when possible.
Migrations and upgrades are supported only from in-cluster Cloud Service Mesh versions 1.9+ installed with Mesh CA. Installations with Istio CA (previously known as Citadel) must first migrate to Mesh CA.
You can use the managed control plane without a GKE Enterprise subscription, but certain UI elements and features in Google Cloud console are only available to GKE Enterprise subscribers. For information about what is available to subscribers and non-subscribers, see GKE Enterprise and Cloud Service Mesh UI differences.
During the provisioning process for a managed control plane, Istio CRDs corresponding to the selected channel are installed in the specified cluster. If there are existing Istio CRDs in the cluster, they will be overwritten.
Managed Cloud Service Mesh only supports the default DNS domain .cluster.local.
New installations of managed Cloud Service Mesh fetch JWKS only using Envoys, unless the fleet contains other clusters for which that behavior is not enabled. This is equivalent to the PILOT_JWT_ENABLE_REMOTE_JWKS=envoy Istio option. Compared to installations that don't have VPCSC_GA_SUPPORTED condition (see below), you might need extra configuration for ServiceEntry and DestinationRule configurations. For an example, see requestauthn-with-se.yaml.tmpl. You can determine whether the current mode of operation is equivalent to PILOT_JWT_ENABLE_REMOTE_JWKS=envoy by determining whether VPC Service Controls are supported for the control plane (ie. the VPCSC_GA_SUPPORTED condition is displayed).
Managed data plane is only supported for workloads without additional sidecars (other than the Cloud Service Mesh sidecar).
Control plane differences
There are differences in supported features between the ISTIOD and TRAFFIC_DIRECTOR control plane implementations. To check which implementation you are using, see Identify control plane implementation.
– indicates the feature is available and enabled by default.
† - indicates that feature APIs may have differences between various platforms.
* – indicates the feature is supported for the platform and can be enabled, as described in Enable optional features or the feature guide linked in the feature table.
§ – indicates that the feature is supported by allowlist. Previous users of managed Anthos Service Mesh are automatically allowlisted at the organization level. Contact Google Cloud Support to request access or to check your allowlist status.
– indicates either the feature isn't available or it isn't supported.
The default and optional features are fully supported by Google Cloud Support. Features not explicitly listed in the tables receive best-effort support.
What determines control plane implementation
When you provision managed Cloud Service Mesh the first time in a fleet, we determine which control plane implementation to use. The same implementation is used for all clusters that provision managed Cloud Service Mesh in that fleet.
New fleets that onboard to managed Cloud Service Mesh receive the TRAFFIC_DIRECTOR control plane implementation, with certain exceptions:
If you are an existing managed Cloud Service Mesh user, you receive the ISTIOD control plane implementation when you onboard a new fleet in the same Google Cloud Organization to managed Cloud Service Mesh, until at least June 30, 2024. If you are one of these users, you can contact Support to fine-tune this behavior. Users whose existing usage is not compatible with the TRAFFIC_DIRECTOR implementation without changes will continue to receive the ISTIOD implementation until September 8, 2024. (These users received a Service Announcement.)
If any GKE on Google Cloud cluster in your fleet contains an in-cluster Cloud Service Mesh control plane when you provision managed Cloud Service Mesh, you will receive the ISTIOD control plane implementation.
If any cluster in your fleet uses GKE Sandbox, when you provision managed Cloud Service Mesh, you receive the ISTIOD control plane implementation.
Managed control plane supported features
Install, upgrade, and rollback
Feature
Managed (TD)
Managed (istiod)
Installation on GKE clusters using fleet feature API
Upgrades from ASM 1.9 versions that use Mesh CA
Direct (skip-level) upgrades from Cloud Service Mesh versions prior to 1.9 (see notes for indirect upgrades)
Direct (skip-level) upgrades from Istio OSS (see notes for indirect upgrades)
Direct (skip-level) upgrades from Istio-on-GKE add-on (see notes for indirect upgrades)
Environments outside of Google Cloud (GKE Enterprise on-premises, GKE Enterprise on other public clouds, Amazon EKS, Microsoft AKS, or other Kubernetes clusters)
Multi-cluster endpoint discovery with declarative API and a simple topology
Notes on terminology
A multi-primary configuration means that the configuration must be replicated in all clusters.
A primary-remote configuration means that a single cluster contains the configuration and is considered the source of truth.
Cloud Service Mesh uses a simplified definition of network based on general connectivity. Workload instances are on the same network if they are able to communicate directly, without a gateway.
Simple topology for multi-cluster endpoint discovery means that every cluster in the fleet either participates or does not participate in endpoints discovery. Complex topologies that are unsupported include (a) one-way endpoint discover (e.g. cluster A can discover endpoints in cluster B but not vice versa) and (b) disjointed endpoint discovery networks (e.g. clusters A and B can discover each other's endpoints, clusters C and D can discover each other's endpoints, but A/B and C/D cannot discover each other's endpoints).
† Cloud Service Mesh with a managed (TD) control plane only supports the distroless image type. You cannot change it.
Note that distroless images have minimal binaries, so you cannot exec the usual commands like bash or curl because they are not present in the distroless image. However, you can use ephemeral containers to attach to a running workload Pod to be able to inspect it and run custom commands. For example, see Collecting Cloud Service Mesh logs.
† The TRAFFIC_DIRECTOR control plane supports a subset of Istio telemetry API used to configure access logs and trace. The TRAFFIC_DIRECTOR control plane does not support configuring the trace sampling rate.
Although TCP is a supported protocol for networking and TCP metrics are collected, they are not reported. Metrics are displayed only for HTTP services in the Google Cloud console.
Services that are configured with Layer 7 capabilities for the following protocols are not supported: WebSocket, MongoDB, Redis, MySQL, Kafka, Cassandra, RabbitMQ, Cloud SQL. You might be able to make the protocol work by using TCP byte stream support. If TCP byte stream cannot support the protocol (for example, Kafka sends a redirect address in a protocol-specific reply and this redirect is incompatible with Cloud Service Mesh's routing logic), then the protocol isn't supported. Although gateway ports can be created with Mongo, MySQL and Redis protocol, the mesh treats the resulting traffic as standard TCP, lacking protocol-specific handling.
† In proxyless gRPC, IPv6 dual-stack features are supported only in gRPC 1.66.1 or newer in C++ and Python, gRPC Go v1.71, and or gRPC Node.js v1.12. If you try to configure dual-stack features with a version of gRPC that doesn't support dual-stack, the clients will use only the first address sent by Traffic Director.
Envoy deployments
Feature
Managed (TD)
Managed (istiod)
Sidecars
Ingress gateway
Egress directly out from sidecars
Egress using egress gateways
*
*
CRD support
Feature
Managed (TD)
Managed (istiod)
Sidecar resource
Service entry resource
Percentage, fault injection, path matching, redirects, retries, rewriting, timeout, retry, mirroring, header manipulation, and CORS routing rules
† The TRAFFIC_DIRECTOR control plane implementation does not support following fields and values in fields:
workloadSelector field
endpoints[].network field
endpoints[].locality field
endpoints[].weight field
endpoints[].serviceAccount field
DNS_ROUND_ROBIN value in resolution field
MESH_INTERNAL value in location field
Unix domain socket address in endpoints[].address field
subjectAltNames field
Two or more endpoints[] entries if resolution field has DNS value
Destination rule
Feature
Managed (TD)
Managed (istiod)
DestinationRule v1beta1
†
† The TRAFFIC_DIRECTOR control plane implementation does not support following fields.
trafficPolicy.loadBalancer.localityLbSetting field
trafficPolicy.tunnel field
trafficPolicy.tls.credentialName field
trafficPolicy.portLevelSettings[].tls.credentialName field
Additionally, the TRAFFIC_DIRECTOR control plane implementation requires that the destination rule defining subsets is in the same namespace and cluster with the Kubernetes service or ServiceEntry.
Sidecar
Feature
Managed (TD)
Managed (istiod)
Sidecar v1beta1
†
† The TRAFFIC_DIRECTOR control plane implementation does not support following fields and values in fields:
[[["Easy to understand","easyToUnderstand","thumb-up"],["Solved my problem","solvedMyProblem","thumb-up"],["Other","otherUp","thumb-up"]],[["Hard to understand","hardToUnderstand","thumb-down"],["Incorrect information or sample code","incorrectInformationOrSampleCode","thumb-down"],["Missing the information/samples I need","missingTheInformationSamplesINeed","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-10-13 UTC."],[],[]]
