Bug Fixes
- core: Fix shutdown failing accepted RPCs during channel startup (02e98a8). This fixes a race where RPCs could fail with "UNAVAILABLE: Channel shutdown invoked" even though they were created before channel.shutdown()
- okhttp: Fix race condition overwriting MAX_CONCURRENT_STREAMS (#12548) (8d49dc1)
- binder: Stop leaking
thisfrom BinderServerTransport's ctor (#12453) (89d77e0) - rls: Avoid missed config update from reentrancy (55ae1d0). This fixes a regression since 1.75.0 triggered by CdsLb being converted to XdsDepManager. Without this fix, a second channel to the same target may hang when starting, causing DEADLINE_EXCEEDED, and unhang when the control plane delivers an update (e.g., endpoint address update)
Improvements
- xds: gRFC A88 - Changes to XdsClient Watcher APIs (#12446) (f385add). We now have improved xDS error handling and this provides a clearer mechanism for the xDS server to report per-resource errors to the client, resulting in better error messages for debugging and faster detection of non-existent resources. This also improves the handling of all xDS-related data errors and the behavior of the xDS resource timer.
- rls: Control plane channel monitor state and back off handling (#12460) (26c1c13). Resets RLS request backoff timers when the Control plane channel state transitions to READY. Also when the backoff timer expires, instead of making a RLS request immediately, it just causes a picker update to allow making rpc again to the RLS target.
- core: simplify DnsNameResolver.resolveAddresses() (4843256)
- netty: Run handshakeCompleteRunnable in success cases (283f103)
- api,netty: Add custom header support for HTTP CONNECT proxy (bbc0aa3)
- binder: Pre-factor out the guts of the BinderClientTransport handshake. (9313e87)
- compiler: Add RISC-V 64-bit architecture support to compiler build configuration (725ab22)
- core: Release lock before closing shared resource (cb73f21). Shared resources are internal to gRPC for sharing expensive objects across channels and servers, like threads. This reduces the chances of forming a deadlock, like seen with s2a in d50098f
- Upgrade gson to 2.12.1 (6dab2ce)
- Upgrade dependencies (f36defa). proto-google-common-protos to 2.63.1, google-auth-library to 1.40.0, error-prone annotations to 2.44.0, guava to 33.5.0-android, opentelemetry to 1.56.0
- compiler: Update maximum supported protobuf edition to EDITION_2024 (2f64092)
- binder: Introduce server authorization strategy v2 (d971072). Adds support for
android:isolatedProcessServices and moves all security checks to the handshake, making subsequent transactions more efficient.
New Features
- compiler: Upgrade to C++ protobuf 33.1 (#12534) (58ae5f8).
- util: Add gRFC A68 random subsetting LB (48a4288). The policy uses the name
random_subsetting_experimental. If it is working for you, tell us so we can gauge marking it stable. While the xDS portions haven’t yet landed, it is possible to use with xDS with JSON-style Structs as supported by gRFC A52 - xds: Support for System Root Certs (#12499) (51611ba). Most service mesh workloads use mTLS, as described in gRFC A29. However, there are cases where it is useful for applications to use normal TLS rather than using certificates for workload identity, such as when a mesh wants to move some workloads behind a reverse proxy. The xDS
CertificateValidationContextmessage (see envoyproxy/envoy#34235) has asystem_root_certsfield. In the gRPC client, if this field is present and theca_certificate_provider_instancefield is unset, system root certificates will be used for validation. This implements gRFC A82. - xds: Support for GCP Authentication Filter (#12499) (51611ba). In service mesh environments, there are cases where intermediate proxies make it impossible to rely on mTLS for end-to-end authentication. These cases can be addressed instead by the use of service account identity JWT tokens. The xDS GCP Authentication filter provides a mechanism for attaching such JWT tokens as gRPC call credentials on GCP. gRPC already supports a framework for xDS HTTP filters, as described in gRFC A39. This release supports the GCP Authentication filter under this framework as described in gRFC A83.
- xds: Support for xDS-based authority rewriting (#12499) (51611ba). gRPC supports getting routing configuration from an xDS server, as described in gRFCs A27 and A28. The xDS configuration can configure the client to rewrite the authority header on requests. This functionality can be useful in cases where the server is using the authority header to make decisions about how to process the request, such as when multiple hosts are handled via a reverse proxy. Note that this feature is solely about rewriting the authority header on data plane RPCs; it does not affect the authority used in the TLS handshake.
As mentioned in gRFC A29, there are use-cases for gRPC that prohibit trusting the xDS server to control security-centric configuration. The authority rewriting feature falls under the same umbrella as mTLS configuration. As a result, the authority rewriting feature will only be enabled when the bootstrap config for the xDS server hastrusted_xds_serverin theserver_featuresfield. - xds: xDS based SNI setting and SAN validation (#12378) (0567531). When using xDS credentials make SNI for the Tls handshake to be configured via xDS, rather than use the channel authority as the SNI, and make SAN validation to be able to use the SNI sent when so instructed via xDS. Implements gRFC A101.
Documentation
- api: Document gRFC A18 TCP_USER_TIMEOUT handling for keepalive (da70387)
- core: Fix AbstractClientStream Javadoc (28a6130)
- examples: Document how to preserve META-INF/services in uber jars (97695d5)