API Changes

• xds: Promote xds server and creds APIs to stable (#4753)
• balancer: add ExitIdle interface to instruct the balancer to attempt to leave the IDLE state by connecting SubConns if appropriate. (#4673)
  • NOTICE: This method will be required by the Balancer interface in the future

Behavior Changes

• xds: update xdsclient to keep valid resources from the response even if it has invalid responses and is NACK'ed (see gRFC 260) (#4743)
• balancer: SubConns no longer automatically reconnect after READY; instead they transition to IDLE on connection loss (#4613)

New Features

• xds: add support for RINGHASH lb-policy and affinity (#4741)
• xds: add support for retry policy in VirtualHosts and Routes (#4738)
• stats: support stats for all retry attempts; support transparent retry (#4749)
• authz: create interceptors for gRPC security policy API (#4664)

Bug Fixes

• transport: fix race in transport stream accessing s.recvCompress (#4641)
• client: fix transparent retries when per-RPC credentials are in use (#4785)
• server: fix bug that net.Conn is leaked if the connection is closed (io.EOF) immediately with no traffic (#4633)
• oauth: Allow access to Google API regional endpoints via Google Default Credentials (#4713)