/**
* Copyright 2012 Netflix, Inc.
*
* 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.netflix.hystrix.examples.basic;
import static org.junit.Assert.*;
import org.junit.Test;
import com.netflix.config.ConfigurationManager;
import com.netflix.config.DynamicBooleanProperty;
import com.netflix.config.DynamicPropertyFactory;
import com.netflix.hystrix.HystrixCommand;
import com.netflix.hystrix.HystrixCommandGroupKey;
import com.netflix.hystrix.HystrixCommandKey;
import com.netflix.hystrix.HystrixCommandProperties;
import com.netflix.hystrix.HystrixCommandProperties.ExecutionIsolationStrategy;
import com.netflix.hystrix.HystrixThreadPoolKey;
import com.netflix.hystrix.strategy.concurrency.HystrixRequestContext;
/**
* Sample {@link HystrixCommand} pattern using a semaphore-isolated command
* that conditionally invokes thread-isolated commands.
*/
public class CommandFacadeWithPrimarySecondary extends HystrixCommand<String> {
private final static DynamicBooleanProperty usePrimary = DynamicPropertyFactory.getInstance().getBooleanProperty("primarySecondary.usePrimary", true);
private final int id;
public CommandFacadeWithPrimarySecondary(int id) {
super(Setter
.withGroupKey(HystrixCommandGroupKey.Factory.asKey("SystemX"))
.andCommandKey(HystrixCommandKey.Factory.asKey("PrimarySecondaryCommand"))
.andCommandPropertiesDefaults(
// we want to default to semaphore-isolation since this wraps
// 2 others commands that are already thread isolated
HystrixCommandProperties.Setter()
.withExecutionIsolationStrategy(ExecutionIsolationStrategy.SEMAPHORE)));
this.id = id;
}
@Override
protected String run() {
if (usePrimary.get()) {
return new PrimaryCommand(id).execute();
} else {
return new SecondaryCommand(id).execute();
}
}
@Override
protected String getFallback() {
return "static-fallback-" + id;
}
@Override
protected String getCacheKey() {
return String.valueOf(id);
}
private static class PrimaryCommand extends HystrixCommand<String> {
private final int id;
private PrimaryCommand(int id) {
super(Setter
.withGroupKey(HystrixCommandGroupKey.Factory.asKey("SystemX"))
.andCommandKey(HystrixCommandKey.Factory.asKey("PrimaryCommand"))
.andThreadPoolKey(HystrixThreadPoolKey.Factory.asKey("PrimaryCommand"))
.andCommandPropertiesDefaults(
// we default to a 600ms timeout for primary
HystrixCommandProperties.Setter().withExecutionIsolationThreadTimeoutInMilliseconds(600)));
this.id = id;
}
@Override
protected String run() {
// perform expensive 'primary' service call
return "responseFromPrimary-" + id;
}
}
private static class SecondaryCommand extends HystrixCommand<String> {
private final int id;
private SecondaryCommand(int id) {
super(Setter
.withGroupKey(HystrixCommandGroupKey.Factory.asKey("SystemX"))
.andCommandKey(HystrixCommandKey.Factory.asKey("SecondaryCommand"))
.andThreadPoolKey(HystrixThreadPoolKey.Factory.asKey("SecondaryCommand"))
.andCommandPropertiesDefaults(
// we default to a 100ms timeout for secondary
HystrixCommandProperties.Setter().withExecutionIsolationThreadTimeoutInMilliseconds(100)));
this.id = id;
}
@Override
protected String run() {
// perform fast 'secondary' service call
return "responseFromSecondary-" + id;
}
}
public static class UnitTest {
@Test
public void testPrimary() {
HystrixRequestContext context = HystrixRequestContext.initializeContext();
try {
ConfigurationManager.getConfigInstance().setProperty("primarySecondary.usePrimary", true);
assertEquals("responseFromPrimary-20", new CommandFacadeWithPrimarySecondary(20).execute());
} finally {
context.shutdown();
ConfigurationManager.getConfigInstance().clear();
}
}
@Test
public void testSecondary() {
HystrixRequestContext context = HystrixRequestContext.initializeContext();
try {
ConfigurationManager.getConfigInstance().setProperty("primarySecondary.usePrimary", false);
assertEquals("responseFromSecondary-20", new CommandFacadeWithPrimarySecondary(20).execute());
} finally {
context.shutdown();
ConfigurationManager.getConfigInstance().clear();
}
}
}
}