The QpsClient no longer executes a fixed number of RPCs but runs for a period of time now (see #83).
After some discussion with @ejona86, we also agreed to remove the "server_threads" parameter
and to no longer use a `DirectExecutor` and thus run the QPS Server without any tweaks and
modifications. We believe/hope that this change will make the comparison between the C++ and
Java versions less "Apples and Oranges".
The "client_threads" parameter was renamed to "concurrent_calls" to better reflect what it
acutally does.
Furthermore, I updated the gradle build script to create separate executables for the
client and the server.
I also added a README.
When running benchmarks using the okhttp transport with lots of
streams per channel we would see the occasional GOAWAY frame with
the server logging exceptions of the like "io.netty.handler.codec.http2.Http2Exception: Request stream 575 is behind the next expected stream 583".
As quickly identified by @ejona86, there is a race between creating a new stream id and writing the header on the wire.
Putting both under the same lock ensures that those two always go together.
After this change the errors disappeared. The perf impact should be small as the actual write to
the socket doesn't happen within the lock, but only the scheduling of the write.
Some early grpc users on Android are using a very old Guava. They are
working on upgrading, but it will take time. This alone is not enough
for "old guava" compilibility; expect more to come.
OkHttp no longer cancels all calls on shutdown, as we want to allow
graceful shutdown. Such cancelling behavior will likely be provided by
Channel in the future.
If the transport had started but negotiation had not completed then
previously channel would be null and shutdown would have no effect. Now
we set channel eagerly, but use a separate variable for determining if
it is safe for general use.
OkHttp should now have a thread-safe implementation of newStream.
Previously 'lock' was not held when checking goAway and the checking in
AbstractClientTransport was redundant.
Netty was thread-safe, but it was very hard to tell what guarantees were
necessary and what guarantees each piece was providing.
Channel is available immediately after connect(), so register callbacks
immediately instead of delaying.
Setting channel is now delayed until it is actually safe to use.
Previously streams were being partially orphaned if there was an
interruption during stream creation. To handle cancellation,
AbstractClientStream's cancel() had to be changed remove the
"optimization" otherwise, again, the stream would be orphaned.
A Gradle protoc plugin is used for generating and compiling the grpc
codegen. The code organization was changed to match what Gradle expects.
Proto 3 is now required.
Eric Anderson
Nathan Mittler
Tim Emiola
Louis Ryan
Mugur Marculescu
Jakob Buchgraber
nabeelmian