This document lists the xDS features supported in various gRPC language implementations and versions.
Note that a gRPC client will simply ignore the configuration of a feature it does not support. The gRPC client does not generate a log to indicate that some configuration was ignored. It is impractical to generate a log and keep it up-to-date because xDS has a large number of APIs that gRPC does not support and the APIs keep evolving too. In the case where an xDS field corresponding to a feature is supported but the value configured for that field is not supported, a gRPC client will NACK such a configuration. We recommend reading the first gRFC on xDS support in gRPC to understand the design philosophy.
Not all cluster load balancing policies are supported. A gRPC client will NACK the configuration that contains unsupported cluster load balancing policy. This will cause all cluster configurations to be rejected by the client because the xDS protocol currently requires rejecting all resources in a given response, rather than being able to reject only an individual resource from the response. Due to this limitation, you must ensure that all clients support the required cluster load balancing policy before configuring that policy for a service. For example, if you change the ROUND_ROBIN policy to RING_HASH, you must ensure that all the clients are upgraded to a version that supports RING_HASH.
The EDS policy will not support overprovisioning, which is different from Envoy. Envoy takes the overprovisioning into account in both locality-weighted load balancing and priority failover, but gRPC assumes that the xDS server will update it to redirect traffic when this kind of graceful failover is needed. gRPC will send the envoy.lb.does_not_support_overprovisioning client feature to the xDS server to tell the xDS server that it will not perform graceful failover; xDS server implementations may use this to decide whether to perform graceful failover themselves.
The EDS policy will not support per-endpoint stats; it will report only per-locality stats.
An lb_endpoint is ignored if the health_status is not HEALTHY or UNKNOWN. The optional load_balancing_weight is always ignored.
Initially, only google_default channel creds will be supported to authenticate with the xDS server.
The gRPC language implementations not listed in the table below do not support xDS features.
| Features | gRFCs | C++, Python, Ruby, PHP | Java | Go | Node |
|---|---|---|---|---|---|
| xDS Infrastructure in gRPC client channel:LDS->RDS->CDS->EDS flowADS stream | A27 | v1.30.0 | v1.30.0 | v1.30.0 | v1.2.0 |
| Load Balancing:Virtual host domains matchingOnly default path ("" or “/”) matchingPriority-based weighted round-robin locality pickingRound-robin endpoint picking within localityCluster route actionClient-side Load reporting via LRS | A27 | v1.30.0 | v1.30.0 | v1.30.0 | v1.2.0 |
| Request matching based on:Path (prefix, full path and safe regex)case_sensitive must be true else config is NACKedHeadersRequest routing to multiple clusters based on weights | A28 | v1.31.0 | v1.31.0 | v1.31.0 | v1.3.0 |
| Case insensitive prefix/full path matching:case_sensitive can be true or false | v1.34.0 | v1.34.0 | v1.34.0 | v1.3.0 | |
| Support for xDS v3 APIs | A30 | v1.36.0 | v1.36.0 | v1.36.0 | v1.4.0 |
| Support for xDS v2 APIs | A27 | < v1.51.0 | < v1.53.0 | TBA | < v1.8.0 |
| Maximum Stream Duration:Only max_stream_duration is supported. | A31 | v1.37.1 | v1.37.1 | v1.37.0 | v1.4.0 |
| Circuit Breaking:Only max_requests is supported. | A32 | v1.37.1 (N/A for PHP) | v1.37.1 | v1.37.0 | v1.4.0 |
| Fault Injection: Only the following fields are supported:delayabortmax_active_faultsheaders | A33 | v1.37.1 | v1.37.1 | v1.37.0 | v1.4.0 |
| Client Status Discovery Service | A40 | v1.37.1 (C++) v1.38.0 (Python) | v1.37.1 | v1.37.0 | v1.5.0 |
| Ring hash load balancing policy: Only the following policy specifiers are supported:headerfilter_state with key io.grpc.channel_idOnly XX_HASH function is supported. | A42 | v1.40.0 (C++ and Python) | v1.40.1 | 1.41.0 | |
| Retry: Only the following fields are supported:retry_on for the following conditions: cancelled, deadline-exceeded, internal, resource-exhausted, and unavailable.num_retriesretry_back_off | A44 | v1.40.0 (C++ and Python) | v1.40.1 | 1.41.0 | |
| Security: Uses certificate providers instead of SDS | A29 | v1.41.0 (C++ and Python) | v1.41.0 | 1.41.0 | |
Authorization (RBAC):LOG action has no effectCEL unsupported and rejected | A41 | v1.51.0 (C++ and Python) | v1.42.0 | 1.42.0 | |
| Outlier Detection: Only the following detection types are supported:Success RateFailure Percentage | A50 | v1.51.0 | v1.49.0 | v1.50.0 | v1.7.0 |