First take for grpclb selection stabilization:
1. Changed DnsNameResolver to return balancer addresses as a GrpcAttributes.ATTR_LB_ADDRS attribute in ResolutionResult, instead of among the addresses.
2. AutoConfiguredLoadBalancerFactory decides LB policy solely based on parsed service config without looking at resolved addresses. Behavior changes:
- If no LB policy is specified in service config, default to pick_first, even if there exist balancer addresses (in attributes).
- If grpclb specified but not available and no other specified policies available, it will fail without fallback to round_robin.
3. GrpclbLoadBalancer populates balancer addresses from ResolvedAddresses's attribute (GrpclbConstants.ATTR_LB_ADDRS) instead of sieving from addresses.
Go to TRANSIENT_FAILURE immediately instead of NOOP if GracefulSwitchLoadBalancer receives resolution error before switching to any delegate.
In most natural usecase, the `gracefulSwitchLb` is a child balancer of some `parentLb`, and the `gracefulSwitchLb` switches to a new `delegateLb` when `parentLb.handleResolvedAddressGroup()`. If the `parentLb` receives a resolution error before receiving any resolved addresses, it should go to TRANSIENT_FAILURE. In this case, it will be more convenient if the initial `gracefulSwitchLb` can go to TRANSIENT_FAILURE directly.
Decouples grpc-core with census, while still preserve the default integration of census in grpc-core. Users wishing to enable census needs to add grpc-census to their runtime classpath.
- Created a grpc-census module:
- Moved CensusStatsModule.java and CensusTracingModule.java into grpc-census from grpc-core. CensusModuleTests.java is also moved. They now belong to io.grpc.census package.
Moved DeprecatedCensusConstants.java into io.grpc.census.internal (is this necessary?) in grpc-census.
- Created CensusStatsAccessor.java and CensusTracingAccessor.java, which are used to create census ClientInterceptor and ServerStreamTracer.Factory.
- Everything in grpc-census are package private, except the accessor classes. They only publicly expose ClientInterceptor and ServerStreamTracer.Factory, no Census specific types are exposed.
- Use runtime reflection to load and apply census stats/tracing to channel/server builders, if grpc-census is found in runtime classpath.
- Removed special APIs on AbstractManagedChannelImplBuilder and AbstractServerImplBuilder for overriding census module. They are only used for testing. Now we changed tests to apply Census ClientInterceptor and ServerStreamTracer.Factory just as normal interceptor/stream tracer factory. Test writer is responsible for taking care of the ordering concerns of interceptors and stream tracer factories.
This PR is to add one more Executor parameter when creating the SslContext.
In Netty, we already have this implementation for passing Executor when creating SslContext: netty/netty#8847. This extra Executor is used to take some time-consuming tasks when doing SSL handshake. However, in current gRPC implementation, we are not using this API.
In this PR, the relevant changes are:
1. get the executorPool from ChannelBuilder or ServerBuilder
2. pass the executorPool all the way down to ClientTlsHandler
3. fill executorPool in when creating SslHandler
`GracefulSwitchLoadBalancer` was doing switch based on `LoadBalancerProvider.getPolicyName()`. This turned out to be very awkward when I have to synthesize a policy name for the provider, and what I actually care about is the identity of the lb provider not necessarily the policy name.
Now `GracefulSwitchLoadBalancer` is doing switch based on identity of `LoadBalancer.Factory`, which is simpler.
The API review for #6279 came up with a more meaningful name that
better explains the intent. A setter for the old name was left in
ManagedChannelBuilder to ease migration to the new name by current
users.
Adds an Executor to NameResolver.Args, which is optionally set on ManagedChannelBuilder. This allows NameResolver implementations to avoid creating their own thread pools if the application already manages its own pools.
Addresses #3703.
Jihun Cho
ZHANG Dapeng
Chengyuan Zhang
Eric Gribkoff
Eric Anderson
Tomo Suzuki
Graeme Morgan
ZhenLian
Ran
Yongwoo Noh
Carl Mastrangelo
Kun Zhang
Grant Oakley