API Changes

mem: Add experimental API SetDefaultBufferPool to change the default buffer pool. (#8806)
- Special Thanks: @vanja-p
experimental/stats: Update MetricsRecorder to require embedding the new UnimplementedMetricsRecorder (a no-op struct) in all implementations for forward compatibility. (#8780)

Behavior Changes

balancer/weightedtarget: Remove handling of Addresses and only handle Endpoints in resolver updates. (#8841)

experimental/stats: Add support for asynchronous gauge metrics through the new AsyncMetricReporter and RegisterAsyncReporter APIs. (#8780)
pickfirst: Add support for weighted random shuffling of endpoints, as described in gRFC A113.
- This is enabled by default, and can be turned off using the environment variable GRPC_EXPERIMENTAL_PF_WEIGHTED_SHUFFLING. (#8864)
xds: Implement :authority rewriting, as specified in gRFC A81. (#8779)
balancer/randomsubsetting: Implement the random_subsetting LB policy, as specified in gRFC A68. (#8650)
- Special Thanks: @marek-szews
server: Include status detail headers, if available, when terminating a stream during request header processing. (#8754)
- Special Thanks: @joybestourous

credentials/tls: Fix a bug where the port was not stripped from the authority override before validation. (#8726)
- Special Thanks: @Atul1710
xds/priority: Fix a bug causing delayed failover to lower-priority clusters when a higher-priority cluster is stuck in CONNECTING state. (#8813)
health: Fix a bug where health checks failed for clients using legacy compression options (WithDecompressor or RPCDecompressor). (#8765)
- Special Thanks: @sanki92
transport: Fix an issue where the HTTP/2 server could skip header size checks when terminating a stream early. (#8769)
- Special Thanks: @joybestourous