This provides more structured data into the application for it to do
special handling.
In general, we would hope most people don't need this functionality, but
it is a good escape hatch to allow users to workaround infrastructure
problems.
This reverts commit eca1f7c1d6.
We want to preserve the status message identical to what the server
sent. We'll need a better way to communicate debugging details.
We think this broke when the stream lifecycle listener was removed.
Observing the stream lifecycle would be the "proper" fix, but it had
notification ordering issues where streams would close before we were
notified of the event that caused the closure, which made it difficult
to provide useful error messages. The ordering of notifications was also
largely undefined.
The long term fix we look forward to is the HTTP/2 child channels, which
should have clearly defined ordering between error notification and
channel closure, and in the order that we need here.
Fixes#1251
NettyServer wasn't usable as public, since its constructor was
package-private. So although this reduces our API, it shouldn't actually
impact anyone.
Fixes#1047
This isn't expected to have much impact once the connection is
established because AbstractNettyHandler.exceptionCaught() wraps all
unknown exceptions with Http2Exception. Fixing that is future work.
Some cases we may now be unwrapping a StatusException, such as one
thrown by MessageDeframer. In general, that seems a Good Thing™, but it
is unclear exactly if it would be perceivable.
Fixes#1181
A few things to note:
- ByteString has gone away in favor of AsciiString.
- Http2Headers now uses CharSequence for all methods, so there are a few places that we have to explicitly check for AsciiString to get the optimizations.
- We now have to specify a graceful shutdown timeout for our Netty handlers. Using 5 seconds.
We've seen an NPE as a side-effect of a failure in protocol negotiation:
Oct 27, 2015 9:27:09 PM io.grpc.transport.netty.ProtocolNegotiators$AbstractBufferingHandler fail
SEVERE: Transport failed during protocol negotiation
java.lang.NullPointerException
at io.grpc.transport.netty.NettyClientHandler$2.visit(NettyClientHandler.java:218)
- Channel builders decide the default port based on whether TLS is used.
- Channel builders populate the default port via an Attributes object
passed to NameResolver.Factory#newNameResolver
- NameResolverRegistry contains all the official NameResolvers. Users
can also add custom NameResolvers to it. It looks up NameResolver by
try-and-fail. It is the default NameResolver.Factory for builders.
DnsNameResolver.
- Pass target as Strings instead of URIs from the channel builder to
ManagedChannelImpl. A target string is not necessarily a valid URI, in
which case ManagedChannelImpl will add "dns:///" to the beginning of
the target and use it as URI.
- DnsNameResolver will require scheme "dns" to be present. It no longer
allows scheme-absent URIs.
- Add NameResolver and LoadBalancer interfaces.
- ManagedChannelImpl now uses NameResolver and LoadBalancer for
transport selection, which may return transports to multiple
addresses.
- Transports are still owned by ManagedChannelImpl, which implements
TransportManager interface that is provided to LoadBalancer, so that
LoadBalancer doesn't worry about Transport lifecycles.
- Channel builders can be created by forTarget() that accepts the fully
qualified target name, which is an URI. (TODO) it's not tested.
- The old address-based construction pattern is supported by using
AbstractManagedChannelImplBuilder.DirectAddressNameResolver.
- (TODO) DnsNameResolver and SimpleLoadBalancer are currently
incomplete. They merely work for the single-address scenario.
NettyClientHandler currently handles non-HTTP/2 exceptions properly by forcing a shutdown of the connection. We need to do the server-side as well.
Fixes#1097
Previously, if the content type was being ignored the error code would
have been UNKNOWN since there was no grpc-status. That seems very to
accidentally pass, so now if the content type is ignored it would get
OK.
ServerCall already had "headers must be sent before any messages, which
must be sent before closing," but the implementation did not enforce it
and our async server handler didn't obey.
The benefit of forcing sending headers first is that it removes the only
implicit call in our API and interceptors dealing just with metadata
don't need to override sendMessage. The implicit behavior was bug-prone
since it wasn't obvious you were forgetting that headers may not be
sent.
nmittler
Carl Mastrangelo
Eric Anderson
Kun Zhang
Louis Ryan
Jakob Buchgraber
Xudong Ma