/*
* 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.event;
import java.util.Calendar;
import java.util.Collections;
import java.util.List;
import org.trpr.platform.model.event.PlatformEvent;
import com.flipkart.phantom.task.spi.Executor;
import com.netflix.hystrix.HystrixCommand;
import com.netflix.hystrix.HystrixEventType;
import com.twitter.zipkin.gen.Span;
/**
* This is an extension of {@link org.trpr.platform.model.event.PlatformEvent}
* which adds few additional fields to the Event.
* <br/>
* <b>
* IMPORTANT- In case of Request TimeOut {@link ServiceProxyEvent#getEventStatus()} is SUCCESS. However {@link ServiceProxyEvent#getHystrixEventList()}
* would contain a TimeOut Event. In case consumer is interested in TimeOuts, it must check {@link ServiceProxyEvent#getHystrixEventList()} to detect
* TimeOut Events.
* </b>
*
* @author amanpreet.singh
* @version 1.0.0
* @since 24/10/13 5:44 PM.
*/
public class ServiceProxyEvent extends PlatformEvent {
/** */
private static final long serialVersionUID = 1L;
/** Sequential list of events which executor executed to serve the request. */
private final List<HystrixEventType> hystrixEventList;
/** In case of failure this field holds the exception which caused the failure otherwise it is {@code null} */
private final Exception exception;
/**
* Command which executor executed. This corresponds to command name, uri, proxy
* in case of Task Handler,HTTP Handler & Thrift Handler Respectively.
*/
private final String commandName;
/** Time it took to execute the command. In case command is not found value is -1. */
private final int executionTime;
/** Time at which request is sent */
private final long requestSentTime;
/** Time at which request is received */
private final long requestReceiveTime;
/** Time at which request starts executing */
private final long requestExecutionStartTime;
/** Request Id corresponding to which this event is generated. */
private final String requestId;
/** The Zipkin span used for tracing */
private Span span;
//Enum just to denote string constants for event status.
enum EventStatus {
SUCCESS, FAILURE
}
private ServiceProxyEvent(Builder builder) {
/** Inherited Fields */
this.eventSource = builder.eventSource;
this.eventType = builder.eventType;
/** Introduced Fields */
this.requestId = builder.requestId;
this.hystrixEventList = builder.hystrixEventList;
this.commandName = builder.commandName;
this.exception = builder.exception;
this.executionTime = builder.executionTime;
this.requestSentTime = builder.requestSentTime;
this.requestReceiveTime = builder.requestReceiveTime;
this.requestExecutionStartTime = builder.requestExecutionStartTime;
this.span = builder.span;
/** EventStatus is SUCCESS in case of request TimeOuts see class description for more detail */
this.eventStatus = exception == null ? EventStatus.SUCCESS.name() : EventStatus.FAILURE.name();
this.eventMessage = exception == null ? EventStatus.SUCCESS.name() : exception.getMessage();
setCreatedDate(Calendar.getInstance());
}
/** Getter methods */
public Exception getException() {
return exception;
}
public List<HystrixEventType> getHystrixEventList() {
return hystrixEventList;
}
public String getCommandName() {
return commandName;
}
public int getExecutionTime() {
return executionTime;
}
public String getRequestId() {
return requestId;
}
public long getRequestReceiveTime() {
return requestReceiveTime;
}
public long getRequestSentTime() {
return requestSentTime;
}
public long getRequestExecutionStartTime() {
return requestExecutionStartTime;
}
public Span getSpan() {
return span;
}
/** End Getter methods */
public static class Builder {
/** Mandatory Fields */
private final String commandName;
private final String eventType;
/** Optional Fields */
private String requestId = null;
private int executionTime = -1;
private long requestSentTime = -1;
private long requestReceiveTime = -1;
private long requestExecutionStartTime = -1;
private Exception exception = null;
private String eventSource = "unspecified";
private List<HystrixEventType> hystrixEventList = Collections.emptyList();
private Span span = null;
/**
* @param commandName Command which executor executed from which this event was generated.
* @param eventType Refer to {@link org.trpr.platform.model.event.PlatformEvent#eventType}
*/
public Builder(String commandName, String eventType) {
this.commandName = commandName;
this.eventType = eventType;
}
/**
* @param eventSource Name of the executor class which executed this event. In case executor was not found it refers to the class
* responsible for finding appropriate executor.
*/
public Builder withEventSource(String eventSource) {
this.eventSource = eventSource;
return this;
}
/**
* @param hystrixEventList Sequential list of events which executor executed to serve the request.
*/
public Builder withEventList(List<HystrixEventType> hystrixEventList) {
this.hystrixEventList = hystrixEventList;
return this;
}
/**
* @param exception In case of failure this field holds the exception which caused the failure.
*/
public Builder withException(Exception exception) {
this.exception = exception;
return this;
}
/**
* @param executionTime Time it took to execute the command. In case command is not found value is -1.
*/
public Builder withExecutionTime(int executionTime) {
this.executionTime = executionTime;
return this;
}
/**
* @param requestId Request Id corresponding to which this event is generated.
*/
public Builder withRequestId(String requestId) {
this.requestId = requestId;
return this;
}
/**
* @param sentTime Time at which request is sent.
*/
public Builder withRequestSentTime(long sentTime) {
this.requestSentTime = sentTime;
return this;
}
/**
* @param receiveTime Time at which request is received.
*/
public Builder withRequestReceiveTime(long receiveTime) {
this.requestReceiveTime = receiveTime;
return this;
}
/**
* @param executionStartTime Time at which actual processing starts for the request.
*/
public Builder withRequestExecutionStartTime(long executionStartTime) {
this.requestExecutionStartTime = executionStartTime;
return this;
}
/**
* @param span the Span that was linked to this event
*/
public Builder withSpan(Span span) {
this.span = span;
return this;
}
/**
* Copies various parameters like execution events,time and any exception after command execution.<br/><br/>
* <b>Should be called only after execution of command completes</b>
* @param executor Executor used to execute this request.
* @return
*/
@SuppressWarnings({ "rawtypes", "unchecked" })
public Builder withCommandData(Executor executor) {
HystrixCommand command = (HystrixCommand) executor;
withEventList(command.getExecutionEvents())
.withExecutionTime(command.getExecutionTimeInMilliseconds())
.withException((Exception) command.getFailedExecutionException());
return this;
}
public ServiceProxyEvent build() {
return new ServiceProxyEvent(this);
}
}
}