/*
* Copyright 2012-2015, the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.flipkart.phantom.runtime.impl.server.netty.handler.thrift;
import java.net.InetAddress;
import java.net.InetSocketAddress;
import java.net.UnknownHostException;
import java.util.Arrays;
import java.util.List;
import org.apache.thrift.protocol.TBinaryProtocol;
import org.apache.thrift.protocol.TMessage;
import org.apache.thrift.protocol.TProtocol;
import org.apache.thrift.protocol.TProtocolFactory;
import org.apache.thrift.transport.TTransport;
import org.jboss.netty.buffer.ChannelBuffer;
import org.jboss.netty.buffer.ChannelBuffers;
import org.jboss.netty.channel.ChannelEvent;
import org.jboss.netty.channel.ChannelHandlerContext;
import org.jboss.netty.channel.ChannelStateEvent;
import org.jboss.netty.channel.Channels;
import org.jboss.netty.channel.ExceptionEvent;
import org.jboss.netty.channel.MessageEvent;
import org.jboss.netty.channel.SimpleChannelHandler;
import org.jboss.netty.channel.SimpleChannelUpstreamHandler;
import org.jboss.netty.channel.group.ChannelGroup;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.InitializingBean;
import org.springframework.util.Assert;
import com.flipkart.phantom.event.ServiceProxyEvent;
import com.flipkart.phantom.event.ServiceProxyEventProducer;
import com.flipkart.phantom.runtime.impl.server.netty.channel.thrift.ThriftNettyChannelBuffer;
import com.flipkart.phantom.task.impl.collector.EventDispatchingSpanCollector;
import com.flipkart.phantom.task.impl.interceptor.ServerRequestInterceptor;
import com.flipkart.phantom.task.spi.Executor;
import com.flipkart.phantom.task.spi.RequestContext;
import com.flipkart.phantom.task.spi.repository.ExecutorRepository;
import com.flipkart.phantom.thrift.impl.ThriftProxy;
import com.flipkart.phantom.thrift.impl.ThriftProxyExecutor;
import com.flipkart.phantom.thrift.impl.ThriftRequestWrapper;
import com.github.kristofa.brave.Brave;
import com.github.kristofa.brave.FixedSampleRateTraceFilter;
import com.github.kristofa.brave.ServerSpan;
import com.github.kristofa.brave.ServerTracer;
import com.github.kristofa.brave.TraceFilter;
import com.google.common.base.Optional;
import rx.Observable;
/**
* <code>ThriftChannelHandler</code> is a sub-type of {@link SimpleChannelHandler} that acts as a proxy for Apache Thrift calls using the binary protocol.
* It wraps the Thrift call using a {@link ThriftProxyExecutor} that provides useful features like monitoring, fallback etc.
*
* @author Regunath B
* @version 1.0, 26 Mar 2013
*/
public class ThriftChannelHandler extends SimpleChannelUpstreamHandler implements InitializingBean {
/** Logger for this class*/
private static final Logger LOGGER = LoggerFactory.getLogger(ThriftChannelHandler.class);
/** The default name of the server/service this channel handler is serving*/
private static final String DEFAULT_SERVICE_NAME = "Thrift Proxy";
/** Event Type for publishing all events which are generated here */
private final static String THRIFT_HANDLER = "THRIFT_HANDLER";
/** The default response size for creating dynamic channel buffers*/
private static final int DEFAULT_RESPONSE_SIZE = 4096;
/** The default value for tracing frequency. This value indicates that tracing if OFF*/
private static final TraceFilter NO_TRACING = new FixedSampleRateTraceFilter(-1);
/** Default host name and port where this ChannelHandler is available */
public static final String DEFAULT_HOST = "localhost"; // unresolved local host name
public static final int DEFAULT_PORT = -1; // no valid port really
/** The local host name value*/
private static String hostName = DEFAULT_HOST;
static {
try {
hostName = InetAddress.getLocalHost().getHostName();
} catch (UnknownHostException e) {
LOGGER.warn("Unable to resolve local host name. Will use default host name : " + DEFAULT_HOST);
}
}
/** The name for the service/server*/
private String serviceName = DEFAULT_SERVICE_NAME;
/** The port where the server for this handler is listening on*/
private int hostPort;
/** The default channel group*/
private ChannelGroup defaultChannelGroup;
/** The Thrift TaskRepository to lookup ThriftServiceProxyClient from */
private ExecutorRepository<ThriftRequestWrapper, TTransport, ThriftProxy> repository;
/** The ThriftHandler of this channel */
private String thriftProxy;
/** The dynamic buffer response size*/
private int responseSize = DEFAULT_RESPONSE_SIZE;
/** The Thrift binary protocol factory*/
private TProtocolFactory protocolFactory = new TBinaryProtocol.Factory();
/** The publisher used to broadcast events to Service Proxy Subscribers */
private ServiceProxyEventProducer eventProducer;
/** The request tracing frequency for this channel handler*/
private TraceFilter traceFilter = NO_TRACING;
/** The EventDispatchingSpanCollector instance used in tracing requests*/
private EventDispatchingSpanCollector eventDispatchingSpanCollector;
/**
* Interface method implementation. Checks if all mandatory properties have been set
* @see org.springframework.beans.factory.InitializingBean#afterPropertiesSet()
*/
public void afterPropertiesSet() throws Exception {
Assert.notNull(this.defaultChannelGroup, "The 'defaultChannelGroup' may not be null");
Assert.notNull(this.repository, "The 'repository' may not be null");
Assert.notNull(this.thriftProxy, "The 'thriftProxy' may not be null");
Assert.notNull(this.eventProducer, "The 'eventProducer' may not be null");
Assert.notNull(this.eventDispatchingSpanCollector, "The 'eventDispatchingSpanCollector' may not be null");
}
/**
* Overriden superclass method. Stores the host port that this handler's server is listening on
* @see org.jboss.netty.channel.SimpleChannelUpstreamHandler#channelBound(org.jboss.netty.channel.ChannelHandlerContext, org.jboss.netty.channel.ChannelStateEvent)
*/
public void channelBound(ChannelHandlerContext ctx,ChannelStateEvent event) throws Exception {
super.channelBound(ctx, event);
if (InetSocketAddress.class.isAssignableFrom(event.getValue().getClass())) {
this.hostPort = ((InetSocketAddress)event.getValue()).getPort();
}
}
/**
* Overriden superclass method. Adds the newly created Channel to the default channel group and calls the super class {@link #channelOpen(ChannelHandlerContext, ChannelStateEvent)} method
* @see org.jboss.netty.channel.SimpleChannelUpstreamHandler#channelOpen(org.jboss.netty.channel.ChannelHandlerContext, org.jboss.netty.channel.ChannelStateEvent)
*/
public void channelOpen(ChannelHandlerContext ctx, ChannelStateEvent event) throws Exception {
super.channelOpen(ctx, event);
this.defaultChannelGroup.add(event.getChannel());
}
/**
* Overridden method. Reads and processes Thrift calls sent to the service proxy. Expects data in the Thrift binary protocol.
* @see org.jboss.netty.channel.SimpleChannelUpstreamHandler#handleUpstream(org.jboss.netty.channel.ChannelHandlerContext, org.jboss.netty.channel.ChannelEvent)
*/
public void handleUpstream(ChannelHandlerContext ctx, ChannelEvent event) throws Exception {
long receiveTime = System.currentTimeMillis();
if (MessageEvent.class.isAssignableFrom(event.getClass())) {
// Prepare input and output
ChannelBuffer input = (ChannelBuffer) ((MessageEvent) event).getMessage();
ChannelBuffer output = ChannelBuffers.dynamicBuffer(responseSize);
TTransport clientTransport = new ThriftNettyChannelBuffer(input, output);
//Get command name
ThriftNettyChannelBuffer ttransport = new ThriftNettyChannelBuffer(input, null);
TProtocol iprot = this.protocolFactory.getProtocol(ttransport);
input.markReaderIndex();
TMessage message = iprot.readMessageBegin();
input.resetReaderIndex();
ThriftRequestWrapper thriftRequestWrapper = new ThriftRequestWrapper();
thriftRequestWrapper.setClientSocket(clientTransport);
thriftRequestWrapper.setMethodName(message.name);
// set the service name for the request
thriftRequestWrapper.setServiceName(Optional.of(this.serviceName));
// Create and process a Server request interceptor. This will initialize the server tracing
ServerRequestInterceptor<ThriftRequestWrapper, TTransport> serverRequestInterceptor = this.initializeServerTracing(thriftRequestWrapper);
//Execute
Executor<ThriftRequestWrapper,TTransport> executor = this.repository.getExecutor(message.name, this.thriftProxy, thriftRequestWrapper);
// set the service name for the request
thriftRequestWrapper.setServiceName(executor.getServiceName());
Observable<TTransport> observableResponse;
try {
observableResponse = executor.observe();
} catch (Exception e) {
RuntimeException runtimeException = new RuntimeException("Error in executing Thrift request: " + thriftProxy + ":" + message.name, e);
informReqTracer(receiveTime, clientTransport, message, serverRequestInterceptor,
executor, Optional.of(runtimeException));
throw runtimeException;
}
observableResponse.subscribe(
(response) -> {
informReqTracer(receiveTime, clientTransport, message, serverRequestInterceptor,
executor, Optional.absent());
// write the result to the output channel buffer
Channels.write(ctx, event.getFuture(), ((ThriftNettyChannelBuffer) clientTransport).getOutputBuffer());
},
(exception) -> {
RuntimeException runtimeException = new RuntimeException("Error in executing Thrift request: " + thriftProxy + ":" + message.name, exception);
informReqTracer(receiveTime, clientTransport, message, serverRequestInterceptor,
executor, Optional.of(runtimeException));
event.getChannel().close();
}
);
}else {
super.handleUpstream(ctx, event);
}
}
private void informReqTracer(long receiveTime, TTransport clientTransport, TMessage message,
ServerRequestInterceptor<ThriftRequestWrapper, TTransport> serverRequestInterceptor,
Executor<ThriftRequestWrapper, TTransport> executor,
Optional<RuntimeException> transportError) {
// finally inform the server request tracer
serverRequestInterceptor.process(clientTransport, transportError);
if (eventProducer != null) {
// Publishes event both in case of success and failure.
ServiceProxyEvent.Builder eventBuilder;
if (executor == null) {
eventBuilder = new ServiceProxyEvent.Builder(thriftProxy + ":" + message.name, THRIFT_HANDLER).withEventSource(getClass().getName());
} else {
eventBuilder = executor.getEventBuilder().withCommandData(executor).withEventSource(executor.getClass().getName());
}
eventBuilder.withRequestReceiveTime(receiveTime);
eventProducer.publishEvent(eventBuilder.build());
} else {
LOGGER.debug("eventProducer not set, not publishing event");
}
}
/**
* Interface method implementation. Closes the underlying channel after logging a warning message
* @see org.jboss.netty.channel.SimpleChannelHandler#exceptionCaught(org.jboss.netty.channel.ChannelHandlerContext, org.jboss.netty.channel.ExceptionEvent)
*/
public void exceptionCaught(ChannelHandlerContext ctx, ExceptionEvent event) throws Exception {
LOGGER.warn("Exception {} thrown on Channel {}. Disconnect initiated",event,event.getChannel());
event.getChannel().close();
super.exceptionCaught(ctx, event);
}
/**
* Initializes server tracing for the specified request
* @param executorHttpRequest the Http request
* @return the initialized ServerRequestInterceptor
*/
private ServerRequestInterceptor<ThriftRequestWrapper, TTransport> initializeServerTracing(ThriftRequestWrapper executorRequest) {
ServerRequestInterceptor<ThriftRequestWrapper, TTransport> serverRequestInterceptor = new ServerRequestInterceptor<ThriftRequestWrapper, TTransport>();
List<TraceFilter> traceFilters = Arrays.<TraceFilter>asList(this.traceFilter);
ServerTracer serverTracer = Brave.getServerTracer(this.eventDispatchingSpanCollector, traceFilters);
serverRequestInterceptor.setEndPointSubmitter(Brave.getEndPointSubmitter());
serverRequestInterceptor.setServerTracer(serverTracer);
serverRequestInterceptor.setServiceHost(ThriftChannelHandler.hostName);
serverRequestInterceptor.setServicePort(this.hostPort);
serverRequestInterceptor.setServiceName(this.serviceName);
// now process the request to initialize tracing
serverRequestInterceptor.process(executorRequest);
// set the server request context on the received request
ServerSpan serverSpan = Brave.getServerSpanThreadBinder().getCurrentServerSpan();
RequestContext serverRequestContext = new RequestContext();
serverRequestContext.setCurrentServerSpan(serverSpan);
executorRequest.setRequestContext(Optional.of(serverRequestContext));
return serverRequestInterceptor;
}
/** Start Getter/Setter methods*/
public ChannelGroup getDefaultChannelGroup() {
return this.defaultChannelGroup;
}
public void setServiceName(String serviceName) {
this.serviceName = serviceName;
}
public void setDefaultChannelGroup(ChannelGroup defaultChannelGroup) {
this.defaultChannelGroup = defaultChannelGroup;
}
public ExecutorRepository<ThriftRequestWrapper,TTransport, ThriftProxy> getRepository() {
return this.repository;
}
public void setRepository(ExecutorRepository<ThriftRequestWrapper,TTransport, ThriftProxy> repository) {
this.repository = repository;
}
public int getResponseSize() {
return this.responseSize;
}
public void setResponseSize(int responseSize) {
this.responseSize = responseSize;
}
public String getThriftProxy() {
return thriftProxy;
}
public void setThriftProxy(String thriftProxy) {
this.thriftProxy = thriftProxy;
}
public void setEventProducer(ServiceProxyEventProducer eventProducer) {
this.eventProducer = eventProducer;
}
public void setTraceFilter(TraceFilter traceFilter) {
this.traceFilter = traceFilter;
}
public void setEventDispatchingSpanCollector(EventDispatchingSpanCollector eventDispatchingSpanCollector) {
this.eventDispatchingSpanCollector = eventDispatchingSpanCollector;
}
/** End Getter/Setter methods */
}