Back to Repositories
Testing Hystrix Command Property Configuration in Netflix/Hystrix

This test suite validates the configuration and property management functionality of Hystrix command properties in Netflix’s Hystrix library. It ensures proper handling of various property types, override mechanisms, and default values in the circuit breaker implementation.
Test Coverage Overview

The test suite provides comprehensive coverage of Hystrix command property configurations, including:
Boolean and Integer property type handling
Multiple override levels (builder, global, instance-specific)
Default value implementations
Circuit breaker configuration parameters
Thread pool property management
Implementation Analysis

The testing approach utilizes JUnit to validate property hierarchy and precedence rules. Tests systematically verify that property values are correctly applied through different configuration methods, with special attention to the override chain: instance-specific properties take precedence over global defaults and builder-provided values.

The implementation employs mock objects and utility methods to create controlled test environments.
Technical Details

Key technical components include:
JUnit test framework
ConfigurationManager for dynamic property management
HystrixCommandProperties test implementations
Mock property builders and test keys
Custom property prefix isolation for unit tests
Best Practices Demonstrated

The test suite exemplifies several testing best practices:
Proper test isolation using unique property prefixes
Thorough cleanup after each test
Comprehensive verification of property override chains
Clear test method naming conventions
Effective use of utility methods to reduce code duplication
netflix/hystrix

hystrix-core/src/test/java/com/netflix/hystrix/HystrixCommandPropertiesTest.java
            
/**
 * Copyright 2015 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;

import static org.junit.Assert.assertEquals;

import org.junit.After;
import org.junit.Test;

import com.netflix.config.ConfigurationManager;
import com.netflix.hystrix.HystrixCommandProperties.ExecutionIsolationStrategy;
import com.netflix.hystrix.HystrixCommandProperties.Setter;
import com.netflix.hystrix.strategy.properties.HystrixProperty;

public class HystrixCommandPropertiesTest {

    /**
     * Utility method for creating baseline properties for unit tests.
     */
    /* package */static HystrixCommandProperties.Setter getUnitTestPropertiesSetter() {
        return new HystrixCommandProperties.Setter()
                .withExecutionTimeoutInMilliseconds(1000)// when an execution will be timed out
                .withExecutionTimeoutEnabled(true)
                .withExecutionIsolationStrategy(ExecutionIsolationStrategy.THREAD) // we want thread execution by default in tests
                .withExecutionIsolationThreadInterruptOnTimeout(true)
                .withExecutionIsolationThreadInterruptOnFutureCancel(true)
                .withCircuitBreakerForceOpen(false) // we don't want short-circuiting by default
                .withCircuitBreakerErrorThresholdPercentage(40) // % of 'marks' that must be failed to trip the circuit
                .withMetricsRollingStatisticalWindowInMilliseconds(5000)// milliseconds back that will be tracked
                .withMetricsRollingStatisticalWindowBuckets(5) // buckets
                .withCircuitBreakerRequestVolumeThreshold(0) // in testing we will not have a threshold unless we're specifically testing that feature
                .withCircuitBreakerSleepWindowInMilliseconds(5000000) // milliseconds after tripping circuit before allowing retry (by default set VERY long as we want it to effectively never allow a singleTest for most unit tests)
                .withCircuitBreakerEnabled(true)
                .withRequestLogEnabled(true)
                .withExecutionIsolationSemaphoreMaxConcurrentRequests(20)
                .withFallbackIsolationSemaphoreMaxConcurrentRequests(10)
                .withFallbackEnabled(true)
                .withCircuitBreakerForceClosed(false)
                .withMetricsRollingPercentileEnabled(true)
                .withRequestCacheEnabled(true)
                .withMetricsRollingPercentileWindowInMilliseconds(60000)
                .withMetricsRollingPercentileWindowBuckets(12)
                .withMetricsRollingPercentileBucketSize(1000)
                .withMetricsHealthSnapshotIntervalInMilliseconds(100);
    }

    /**
     * Return a static representation of the properties with values from the Builder so that UnitTests can create properties that are not affected by the actual implementations which pick up their
     * values dynamically.
     * 
     * @param builder command properties builder
     * @return HystrixCommandProperties
     */
    /* package */static HystrixCommandProperties asMock(final Setter builder) {
        return new HystrixCommandProperties(TestKey.TEST) {

            @Override
            public HystrixProperty<Boolean> circuitBreakerEnabled() {
                return HystrixProperty.Factory.asProperty(builder.getCircuitBreakerEnabled());
            }

            @Override
            public HystrixProperty<Integer> circuitBreakerErrorThresholdPercentage() {
                return HystrixProperty.Factory.asProperty(builder.getCircuitBreakerErrorThresholdPercentage());
            }

            @Override
            public HystrixProperty<Boolean> circuitBreakerForceClosed() {
                return HystrixProperty.Factory.asProperty(builder.getCircuitBreakerForceClosed());
            }

            @Override
            public HystrixProperty<Boolean> circuitBreakerForceOpen() {
                return HystrixProperty.Factory.asProperty(builder.getCircuitBreakerForceOpen());
            }

            @Override
            public HystrixProperty<Integer> circuitBreakerRequestVolumeThreshold() {
                return HystrixProperty.Factory.asProperty(builder.getCircuitBreakerRequestVolumeThreshold());
            }

            @Override
            public HystrixProperty<Integer> circuitBreakerSleepWindowInMilliseconds() {
                return HystrixProperty.Factory.asProperty(builder.getCircuitBreakerSleepWindowInMilliseconds());
            }

            @Override
            public HystrixProperty<Integer> executionIsolationSemaphoreMaxConcurrentRequests() {
                return HystrixProperty.Factory.asProperty(builder.getExecutionIsolationSemaphoreMaxConcurrentRequests());
            }

            @Override
            public HystrixProperty<ExecutionIsolationStrategy> executionIsolationStrategy() {
                return HystrixProperty.Factory.asProperty(builder.getExecutionIsolationStrategy());
            }

            @Override
            public HystrixProperty<Boolean> executionIsolationThreadInterruptOnTimeout() {
                return HystrixProperty.Factory.asProperty(builder.getExecutionIsolationThreadInterruptOnTimeout());
            }

            @Override
            public HystrixProperty<Boolean> executionIsolationThreadInterruptOnFutureCancel() {
                return HystrixProperty.Factory.asProperty(builder.getExecutionIsolationThreadInterruptOnFutureCancel());
            }

            @Override
            public HystrixProperty<String> executionIsolationThreadPoolKeyOverride() {
                return HystrixProperty.Factory.nullProperty();
            }

            @Override
            public HystrixProperty<Integer> executionTimeoutInMilliseconds() {
                return HystrixProperty.Factory.asProperty(builder.getExecutionTimeoutInMilliseconds());
            }

            @Override
            public HystrixProperty<Boolean> executionTimeoutEnabled() {
                return HystrixProperty.Factory.asProperty(builder.getExecutionTimeoutEnabled());
            }

            @Override
            public HystrixProperty<Integer> fallbackIsolationSemaphoreMaxConcurrentRequests() {
                return HystrixProperty.Factory.asProperty(builder.getFallbackIsolationSemaphoreMaxConcurrentRequests());
            }

            @Override
            public HystrixProperty<Boolean> fallbackEnabled() {
                return HystrixProperty.Factory.asProperty(builder.getFallbackEnabled());
            }

            @Override
            public HystrixProperty<Integer> metricsHealthSnapshotIntervalInMilliseconds() {
                return HystrixProperty.Factory.asProperty(builder.getMetricsHealthSnapshotIntervalInMilliseconds());
            }

            @Override
            public HystrixProperty<Integer> metricsRollingPercentileBucketSize() {
                return HystrixProperty.Factory.asProperty(builder.getMetricsRollingPercentileBucketSize());
            }

            @Override
            public HystrixProperty<Boolean> metricsRollingPercentileEnabled() {
                return HystrixProperty.Factory.asProperty(builder.getMetricsRollingPercentileEnabled());
            }

            @Override
            public HystrixProperty<Integer> metricsRollingPercentileWindow() {
                return HystrixProperty.Factory.asProperty(builder.getMetricsRollingPercentileWindowInMilliseconds());
            }

            @Override
            public HystrixProperty<Integer> metricsRollingPercentileWindowBuckets() {
                return HystrixProperty.Factory.asProperty(builder.getMetricsRollingPercentileWindowBuckets());
            }

            @Override
            public HystrixProperty<Integer> metricsRollingStatisticalWindowInMilliseconds() {
                return HystrixProperty.Factory.asProperty(builder.getMetricsRollingStatisticalWindowInMilliseconds());
            }

            @Override
            public HystrixProperty<Integer> metricsRollingStatisticalWindowBuckets() {
                return HystrixProperty.Factory.asProperty(builder.getMetricsRollingStatisticalWindowBuckets());
            }

            @Override
            public HystrixProperty<Boolean> requestCacheEnabled() {
                return HystrixProperty.Factory.asProperty(builder.getRequestCacheEnabled());
            }

            @Override
            public HystrixProperty<Boolean> requestLogEnabled() {
                return HystrixProperty.Factory.asProperty(builder.getRequestLogEnabled());
            }

        };
    }

    // NOTE: We use "unitTestPrefix" as a prefix so we can't end up pulling in external properties that change unit test behavior

    public enum TestKey implements HystrixCommandKey {
        TEST
    }

    private static class TestPropertiesCommand extends HystrixCommandProperties {

        protected TestPropertiesCommand(HystrixCommandKey key, Setter builder, String propertyPrefix) {
            super(key, builder, propertyPrefix);
        }

    }

    @After
    public void cleanup() {
        ConfigurationManager.getConfigInstance().clear();
    }

    @Test
    public void testBooleanBuilderOverride1() {
        HystrixCommandProperties properties = new TestPropertiesCommand(TestKey.TEST,
                new HystrixCommandProperties.Setter().withCircuitBreakerForceClosed(true), "unitTestPrefix");

        // the builder override should take precedence over the default
        assertEquals(true, properties.circuitBreakerForceClosed().get());
    }

    @Test
    public void testBooleanBuilderOverride2() {
        HystrixCommandProperties properties = new TestPropertiesCommand(TestKey.TEST,
                new HystrixCommandProperties.Setter().withCircuitBreakerForceClosed(false), "unitTestPrefix");

        // the builder override should take precedence over the default
        assertEquals(false, properties.circuitBreakerForceClosed().get());
    }

    @Test
    public void testBooleanCodeDefault() {
        HystrixCommandProperties properties = new TestPropertiesCommand(TestKey.TEST, new HystrixCommandProperties.Setter(), "unitTestPrefix");
        assertEquals(HystrixCommandProperties.default_circuitBreakerForceClosed, properties.circuitBreakerForceClosed().get());
    }

    @Test
    public void testBooleanGlobalDynamicOverrideOfCodeDefault() throws Exception {
        HystrixCommandProperties properties = new TestPropertiesCommand(TestKey.TEST, new HystrixCommandProperties.Setter(), "unitTestPrefix");
        ConfigurationManager.getConfigInstance().setProperty("unitTestPrefix.command.default.circuitBreaker.forceClosed", true);

        // the global dynamic property should take precedence over the default
        assertEquals(true, properties.circuitBreakerForceClosed().get());

        // cleanup 
        ConfigurationManager.getConfigInstance().clearProperty("unitTestPrefix.command.default.circuitBreaker.forceClosed");
    }

    @Test
    public void testBooleanInstanceBuilderOverrideOfGlobalDynamicOverride1() throws Exception {
        HystrixCommandProperties properties = new TestPropertiesCommand(TestKey.TEST,
                new HystrixCommandProperties.Setter().withCircuitBreakerForceClosed(true), "unitTestPrefix");
        ConfigurationManager.getConfigInstance().setProperty("unitTestPrefix.command.default.circuitBreaker.forceClosed", false);

        // the builder injected should take precedence over the global dynamic property
        assertEquals(true, properties.circuitBreakerForceClosed().get());

        // cleanup 
        ConfigurationManager.getConfigInstance().clearProperty("unitTestPrefix.command.default.circuitBreaker.forceClosed");
    }

    @Test
    public void testBooleanInstanceBuilderOverrideOfGlobalDynamicOverride2() throws Exception {
        HystrixCommandProperties properties = new TestPropertiesCommand(TestKey.TEST,
                new HystrixCommandProperties.Setter().withCircuitBreakerForceClosed(false), "unitTestPrefix");
        ConfigurationManager.getConfigInstance().setProperty("unitTestPrefix.command.default.circuitBreaker.forceClosed", true);

        // the builder injected should take precedence over the global dynamic property
        assertEquals(false, properties.circuitBreakerForceClosed().get());

        // cleanup 
        ConfigurationManager.getConfigInstance().clearProperty("unitTestPrefix.command.default.circuitBreaker.forceClosed");
    }

    @Test
    public void testBooleanInstanceDynamicOverrideOfEverything() throws Exception {
        HystrixCommandProperties properties = new TestPropertiesCommand(TestKey.TEST,
                new HystrixCommandProperties.Setter().withCircuitBreakerForceClosed(false), "unitTestPrefix");
        ConfigurationManager.getConfigInstance().setProperty("unitTestPrefix.command.default.circuitBreaker.forceClosed", false);
        ConfigurationManager.getConfigInstance().setProperty("unitTestPrefix.command.TEST.circuitBreaker.forceClosed", true);

        // the instance specific dynamic property should take precedence over everything
        assertEquals(true, properties.circuitBreakerForceClosed().get());

        // cleanup 
        ConfigurationManager.getConfigInstance().clearProperty("unitTestPrefix.command.default.circuitBreaker.forceClosed");
        ConfigurationManager.getConfigInstance().clearProperty("unitTestPrefix.command.TEST.circuitBreaker.forceClosed");
    }

    @Test
    public void testIntegerBuilderOverride() {
        HystrixCommandProperties properties = new TestPropertiesCommand(TestKey.TEST,
                new HystrixCommandProperties.Setter().withMetricsRollingStatisticalWindowInMilliseconds(5000), "unitTestPrefix");

        // the builder override should take precedence over the default
        assertEquals(5000, properties.metricsRollingStatisticalWindowInMilliseconds().get().intValue());
    }

    @Test
    public void testIntegerCodeDefault() {
        HystrixCommandProperties properties = new TestPropertiesCommand(TestKey.TEST, new HystrixCommandProperties.Setter(), "unitTestPrefix");
        assertEquals(HystrixCommandProperties.default_metricsRollingStatisticalWindow, properties.metricsRollingStatisticalWindowInMilliseconds().get());
    }

    @Test
    public void testIntegerGlobalDynamicOverrideOfCodeDefault() throws Exception {
        HystrixCommandProperties properties = new TestPropertiesCommand(TestKey.TEST, new HystrixCommandProperties.Setter(), "unitTestPrefix");
        ConfigurationManager.getConfigInstance().setProperty("unitTestPrefix.command.default.metrics.rollingStats.timeInMilliseconds", 1234);

        // the global dynamic property should take precedence over the default
        assertEquals(1234, properties.metricsRollingStatisticalWindowInMilliseconds().get().intValue());

        // cleanup 
        ConfigurationManager.getConfigInstance().clearProperty("unitTestPrefix.command.default.metrics.rollingStats.timeInMilliseconds");
    }

    @Test
    public void testIntegerInstanceBuilderOverrideOfGlobalDynamicOverride() throws Exception {
        HystrixCommandProperties properties = new TestPropertiesCommand(TestKey.TEST,
                new HystrixCommandProperties.Setter().withMetricsRollingStatisticalWindowInMilliseconds(5000), "unitTestPrefix");
        ConfigurationManager.getConfigInstance().setProperty("unitTestPrefix.command.default.rollingStats.timeInMilliseconds", 3456);

        // the builder injected should take precedence over the global dynamic property
        assertEquals(5000, properties.metricsRollingStatisticalWindowInMilliseconds().get().intValue());

        // cleanup 
        ConfigurationManager.getConfigInstance().clearProperty("unitTestPrefix.command.default.rollingStats.timeInMilliseconds");
    }

    @Test
    public void testIntegerInstanceDynamicOverrideOfEverything() throws Exception {
        HystrixCommandProperties properties = new TestPropertiesCommand(TestKey.TEST,
                new HystrixCommandProperties.Setter().withMetricsRollingStatisticalWindowInMilliseconds(5000), "unitTestPrefix");
        ConfigurationManager.getConfigInstance().setProperty("unitTestPrefix.command.default.metrics.rollingStats.timeInMilliseconds", 1234);
        ConfigurationManager.getConfigInstance().setProperty("unitTestPrefix.command.TEST.metrics.rollingStats.timeInMilliseconds", 3456);

        // the instance specific dynamic property should take precedence over everything
        assertEquals(3456, properties.metricsRollingStatisticalWindowInMilliseconds().get().intValue());

        // cleanup 
        ConfigurationManager.getConfigInstance().clearProperty("unitTestPrefix.command.default.metrics.rollingStats.timeInMilliseconds");
        ConfigurationManager.getConfigInstance().clearProperty("unitTestPrefix.command.TEST.metrics.rollingStats.timeInMilliseconds");
    }

    @Test
    public void testThreadPoolOnlyHasInstanceOverride() throws Exception {
        HystrixCommandProperties properties = new TestPropertiesCommand(TestKey.TEST, new HystrixCommandProperties.Setter(), "unitTestPrefix");
        ConfigurationManager.getConfigInstance().setProperty("unitTestPrefix.command.default.threadPoolKeyOverride", 1234);
        // it should be null
        assertEquals(null, properties.executionIsolationThreadPoolKeyOverride().get());
        ConfigurationManager.getConfigInstance().setProperty("unitTestPrefix.command.TEST.threadPoolKeyOverride", "testPool");
        // now it should have a value
        assertEquals("testPool", properties.executionIsolationThreadPoolKeyOverride().get());

        // cleanup 
        ConfigurationManager.getConfigInstance().clearProperty("unitTestPrefix.command.default.threadPoolKeyOverride");
        ConfigurationManager.getConfigInstance().clearProperty("unitTestPrefix.command.TEST.threadPoolKeyOverride");
    }

}