commit | 132f7a9a3385d58d06fbe4b80d3290139c76b14a | [log] [tgz] |
---|---|---|
author | Kun Zhang <zhangkun83@users.noreply.github.com> | Thu Oct 06 17:15:24 2016 -0700 |
committer | GitHub <noreply@github.com> | Thu Oct 06 17:15:24 2016 -0700 |
tree | a042b2c18a7a307ca789de50ff7d4884217eb6ad | |
parent | 4e5765a93ffdd23e721357170e365c068e0b990d [diff] |
core: Census integration for stats (#2262) Highlights ========== StatsTraceContext ----------------- The bridge between gRPC library and Census. It keeps track of the total payload sizes and the elapsed time of a Call. The rest of the gRPC code doesn't invoke Census directly. Context propagation ------------------- StatsTraceContext carries CensusContext (and the upcoming TraceContext) and is attached to the gRPC Context. 1. StatsTraceContext is created by ManagedChannelImpl, by calling createClientContext(), which inherits the current CensusContext if available. 2. ManagedChannelImpl passes StatsTraceContext to ClientCallImpl, then to the stream, then to the framer and deframer explicitly. 3. ClientCallImpl propagates the CensusContext to the headers. 1. ServerImpl creates a StatsTraceContext by implementing a new callback method StatsTraceContext methodDetermined(MethodDescriptor, Metadata) on ServerTransportListener. 2. NettyServerHandler calls methodDetermined() before creating the stream, and passes the StatsTraceContext to the stream. 3. When ServerImpl creates the gRPC Context for the new ServerCall, it calls the new method statsTraceContext() on ServerStream and puts the StatsTraceContext in the Context. Metrics recording ----------------- 1. Client-side start time: when ClientCallImpl is created 2. Server-side start time: when methodDetermined() is called 3. Server-side end time: in ServerStreamListener.closed(), but before calling onComplete() or onCancel() on ServerCall.Listener. 4. Client-side end time: in ClientStreamListener.closed(), but before calling onClonse() on ClientCall.Listener Message sizes are recorded in MessageFramer and MessageDeframer. Both the uncompressed and wire (possibly compressed) payload sizes are counted. TODOs ===== The CensusContext created from headers on the server side should be attached to the gRPC Context for the call. It's not done at this moment because Census lacks the proper API to do it. It only affects tracing and resource accounting, but doesn't affect stats functionality
gRPC-Java works with JDK 6. TLS usage typically requires using Java 8, or Play Services Dynamic Security Provider on Android. Please see the Security Readme.
Download the JARs. Or for Maven with non-Android, add to your pom.xml
:
<dependency> <groupId>io.grpc</groupId> <artifactId>grpc-netty</artifactId> <version>1.0.1</version> </dependency> <dependency> <groupId>io.grpc</groupId> <artifactId>grpc-protobuf</artifactId> <version>1.0.1</version> </dependency> <dependency> <groupId>io.grpc</groupId> <artifactId>grpc-stub</artifactId> <version>1.0.1</version> </dependency>
Or for Gradle with non-Android, add to your dependencies:
compile 'io.grpc:grpc-netty:1.0.1' compile 'io.grpc:grpc-protobuf:1.0.1' compile 'io.grpc:grpc-stub:1.0.1'
For Android client, use grpc-okhttp
instead of grpc-netty
and grpc-protobuf-lite
or grpc-protobuf-nano
instead of grpc-protobuf
:
compile 'io.grpc:grpc-okhttp:1.0.1' compile 'io.grpc:grpc-protobuf-lite:1.0.1' compile 'io.grpc:grpc-stub:1.0.1'
Development snapshots are available in Sonatypes's snapshot repository.
For protobuf-based codegen, you can put your proto files in the src/main/proto
and src/test/proto
directories along with an appropriate plugin.
For protobuf-based codegen integrated with the Maven build system, you can use protobuf-maven-plugin:
<build> <extensions> <extension> <groupId>kr.motd.maven</groupId> <artifactId>os-maven-plugin</artifactId> <version>1.4.1.Final</version> </extension> </extensions> <plugins> <plugin> <groupId>org.xolstice.maven.plugins</groupId> <artifactId>protobuf-maven-plugin</artifactId> <version>0.5.0</version> <configuration> <!-- The version of protoc must match protobuf-java. If you don't depend on protobuf-java directly, you will be transitively depending on the protobuf-java version that grpc depends on. --> <protocArtifact>com.google.protobuf:protoc:3.0.2:exe:${os.detected.classifier}</protocArtifact> <pluginId>grpc-java</pluginId> <pluginArtifact>io.grpc:protoc-gen-grpc-java:1.0.1:exe:${os.detected.classifier}</pluginArtifact> </configuration> <executions> <execution> <goals> <goal>compile</goal> <goal>compile-custom</goal> </goals> </execution> </executions> </plugin> </plugins> </build>
For protobuf-based codegen integrated with the Gradle build system, you can use protobuf-gradle-plugin:
apply plugin: 'java' apply plugin: 'com.google.protobuf' buildscript { repositories { mavenCentral() } dependencies { // ASSUMES GRADLE 2.12 OR HIGHER. Use plugin version 0.7.5 with earlier // gradle versions classpath 'com.google.protobuf:protobuf-gradle-plugin:0.8.0' } } protobuf { protoc { // The version of protoc must match protobuf-java. If you don't depend on // protobuf-java directly, you will be transitively depending on the // protobuf-java version that grpc depends on. artifact = "com.google.protobuf:protoc:3.0.2" } plugins { grpc { artifact = 'io.grpc:protoc-gen-grpc-java:1.0.1' } } generateProtoTasks { all()*.plugins { grpc {} } } }
If you are making changes to gRPC-Java, see the compiling instructions.
Here's a quick readers' guide to the code to help folks get started. At a high level there are three distinct layers to the library: Stub, Channel & Transport.
The Stub layer is what is exposed to most developers and provides type-safe bindings to whatever datamodel/IDL/interface you are adapting. gRPC comes with a plugin to the protocol-buffers compiler that generates Stub interfaces out of .proto
files, but bindings to other datamodel/IDL should be trivial to add and are welcome.
The Channel layer is an abstraction over Transport handling that is suitable for interception/decoration and exposes more behavior to the application than the Stub layer. It is intended to be easy for application frameworks to use this layer to address cross-cutting concerns such as logging, monitoring, auth etc. Flow-control is also exposed at this layer to allow more sophisticated applications to interact with it directly.
The Transport layer does the heavy lifting of putting and taking bytes off the wire. The interfaces to it are abstract just enough to allow plugging in of different implementations. Transports are modeled as Stream
factories. The variation in interface between a server Stream and a client Stream exists to codify their differing semantics for cancellation and error reporting.
Note the transport layer API is considered internal to gRPC and has weaker API guarantees than the core API under package io.grpc
.
gRPC comes with three Transport implementations:
Tests showing how these layers are composed to execute calls using protobuf messages can be found here https://github.com/google/grpc-java/tree/master/interop-testing/src/main/java/io/grpc/testing/integration