Java tutorial
/** * Copyright 2016 Netflix, Inc. * <p/> * 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 * <p/> * http://www.apache.org/licenses/LICENSE-2.0 * <p/> * 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.contrib.sample.stream; import com.fasterxml.jackson.core.JsonFactory; import com.fasterxml.jackson.core.JsonGenerator; import com.netflix.hystrix.HystrixCollapserKey; import com.netflix.hystrix.HystrixCommandKey; import com.netflix.hystrix.HystrixThreadPoolKey; import com.netflix.hystrix.config.HystrixCollapserConfiguration; import com.netflix.hystrix.config.HystrixCommandConfiguration; import com.netflix.hystrix.config.HystrixConfiguration; import com.netflix.hystrix.config.HystrixConfigurationStream; import com.netflix.hystrix.config.HystrixThreadPoolConfiguration; import com.netflix.hystrix.metric.HystrixRequestEventsStream; import rx.Observable; import rx.functions.Func1; import java.io.IOException; import java.io.StringWriter; import java.util.Map; /** * Links HystrixConfigurationStream and JSON encoding. This may be consumed in a variety of ways: * -such as- * <ul> * <li> {@link HystrixConfigSseServlet} for mapping a specific URL to this data as an SSE stream * <li> Consumer of your choice that wants control over where to embed this stream * </ul> * * @deprecated Instead, prefer mapping your preferred serialization on top of {@link HystrixConfigurationStream#observe()}. */ @Deprecated //since 1.5.4 public class HystrixConfigurationJsonStream { private static final JsonFactory jsonFactory = new JsonFactory(); private final Func1<Integer, Observable<HystrixConfiguration>> streamGenerator; @Deprecated //since 1.5.4 public HystrixConfigurationJsonStream() { this.streamGenerator = new Func1<Integer, Observable<HystrixConfiguration>>() { @Override public Observable<HystrixConfiguration> call(Integer delay) { return HystrixConfigurationStream.getInstance().observe(); } }; } @Deprecated //since 1.5.4 public HystrixConfigurationJsonStream(Func1<Integer, Observable<HystrixConfiguration>> streamGenerator) { this.streamGenerator = streamGenerator; } private static final Func1<HystrixConfiguration, String> convertToJson = new Func1<HystrixConfiguration, String>() { @Override public String call(HystrixConfiguration hystrixConfiguration) { try { return convertToString(hystrixConfiguration); } catch (IOException ioe) { throw new RuntimeException(ioe); } } }; private static void writeCommandConfigJson(JsonGenerator json, HystrixCommandKey key, HystrixCommandConfiguration commandConfig) throws IOException { json.writeObjectFieldStart(key.name()); json.writeStringField("threadPoolKey", commandConfig.getThreadPoolKey().name()); json.writeStringField("groupKey", commandConfig.getGroupKey().name()); json.writeObjectFieldStart("execution"); HystrixCommandConfiguration.HystrixCommandExecutionConfig executionConfig = commandConfig .getExecutionConfig(); json.writeStringField("isolationStrategy", executionConfig.getIsolationStrategy().name()); json.writeStringField("threadPoolKeyOverride", executionConfig.getThreadPoolKeyOverride()); json.writeBooleanField("requestCacheEnabled", executionConfig.isRequestCacheEnabled()); json.writeBooleanField("requestLogEnabled", executionConfig.isRequestLogEnabled()); json.writeBooleanField("timeoutEnabled", executionConfig.isTimeoutEnabled()); json.writeBooleanField("fallbackEnabled", executionConfig.isFallbackEnabled()); json.writeNumberField("timeoutInMilliseconds", executionConfig.getTimeoutInMilliseconds()); json.writeNumberField("semaphoreSize", executionConfig.getSemaphoreMaxConcurrentRequests()); json.writeNumberField("fallbackSemaphoreSize", executionConfig.getFallbackMaxConcurrentRequest()); json.writeBooleanField("threadInterruptOnTimeout", executionConfig.isThreadInterruptOnTimeout()); json.writeEndObject(); json.writeObjectFieldStart("metrics"); HystrixCommandConfiguration.HystrixCommandMetricsConfig metricsConfig = commandConfig.getMetricsConfig(); json.writeNumberField("healthBucketSizeInMs", metricsConfig.getHealthIntervalInMilliseconds()); json.writeNumberField("percentileBucketSizeInMilliseconds", metricsConfig.getRollingPercentileBucketSizeInMilliseconds()); json.writeNumberField("percentileBucketCount", metricsConfig.getRollingCounterNumberOfBuckets()); json.writeBooleanField("percentileEnabled", metricsConfig.isRollingPercentileEnabled()); json.writeNumberField("counterBucketSizeInMilliseconds", metricsConfig.getRollingCounterBucketSizeInMilliseconds()); json.writeNumberField("counterBucketCount", metricsConfig.getRollingCounterNumberOfBuckets()); json.writeEndObject(); json.writeObjectFieldStart("circuitBreaker"); HystrixCommandConfiguration.HystrixCommandCircuitBreakerConfig circuitBreakerConfig = commandConfig .getCircuitBreakerConfig(); json.writeBooleanField("enabled", circuitBreakerConfig.isEnabled()); json.writeBooleanField("isForcedOpen", circuitBreakerConfig.isForceOpen()); json.writeBooleanField("isForcedClosed", circuitBreakerConfig.isForceOpen()); json.writeNumberField("requestVolumeThreshold", circuitBreakerConfig.getRequestVolumeThreshold()); json.writeNumberField("errorPercentageThreshold", circuitBreakerConfig.getErrorThresholdPercentage()); json.writeNumberField("sleepInMilliseconds", circuitBreakerConfig.getSleepWindowInMilliseconds()); json.writeEndObject(); json.writeEndObject(); } private static void writeThreadPoolConfigJson(JsonGenerator json, HystrixThreadPoolKey threadPoolKey, HystrixThreadPoolConfiguration threadPoolConfig) throws IOException { json.writeObjectFieldStart(threadPoolKey.name()); json.writeNumberField("coreSize", threadPoolConfig.getCoreSize()); json.writeNumberField("maximumSize", threadPoolConfig.getMaximumSize()); json.writeNumberField("actualMaximumSize", threadPoolConfig.getActualMaximumSize()); json.writeNumberField("maxQueueSize", threadPoolConfig.getMaxQueueSize()); json.writeNumberField("queueRejectionThreshold", threadPoolConfig.getQueueRejectionThreshold()); json.writeNumberField("keepAliveTimeInMinutes", threadPoolConfig.getKeepAliveTimeInMinutes()); json.writeBooleanField("allowMaximumSizeToDivergeFromCoreSize", threadPoolConfig.getAllowMaximumSizeToDivergeFromCoreSize()); json.writeNumberField("counterBucketSizeInMilliseconds", threadPoolConfig.getRollingCounterBucketSizeInMilliseconds()); json.writeNumberField("counterBucketCount", threadPoolConfig.getRollingCounterNumberOfBuckets()); json.writeEndObject(); } private static void writeCollapserConfigJson(JsonGenerator json, HystrixCollapserKey collapserKey, HystrixCollapserConfiguration collapserConfig) throws IOException { json.writeObjectFieldStart(collapserKey.name()); json.writeNumberField("maxRequestsInBatch", collapserConfig.getMaxRequestsInBatch()); json.writeNumberField("timerDelayInMilliseconds", collapserConfig.getTimerDelayInMilliseconds()); json.writeBooleanField("requestCacheEnabled", collapserConfig.isRequestCacheEnabled()); json.writeObjectFieldStart("metrics"); HystrixCollapserConfiguration.CollapserMetricsConfig metricsConfig = collapserConfig .getCollapserMetricsConfig(); json.writeNumberField("percentileBucketSizeInMilliseconds", metricsConfig.getRollingPercentileBucketSizeInMilliseconds()); json.writeNumberField("percentileBucketCount", metricsConfig.getRollingCounterNumberOfBuckets()); json.writeBooleanField("percentileEnabled", metricsConfig.isRollingPercentileEnabled()); json.writeNumberField("counterBucketSizeInMilliseconds", metricsConfig.getRollingCounterBucketSizeInMilliseconds()); json.writeNumberField("counterBucketCount", metricsConfig.getRollingCounterNumberOfBuckets()); json.writeEndObject(); json.writeEndObject(); } public static String convertToString(HystrixConfiguration config) throws IOException { StringWriter jsonString = new StringWriter(); JsonGenerator json = jsonFactory.createGenerator(jsonString); json.writeStartObject(); json.writeStringField("type", "HystrixConfig"); json.writeObjectFieldStart("commands"); for (Map.Entry<HystrixCommandKey, HystrixCommandConfiguration> entry : config.getCommandConfig() .entrySet()) { final HystrixCommandKey key = entry.getKey(); final HystrixCommandConfiguration commandConfig = entry.getValue(); writeCommandConfigJson(json, key, commandConfig); } json.writeEndObject(); json.writeObjectFieldStart("threadpools"); for (Map.Entry<HystrixThreadPoolKey, HystrixThreadPoolConfiguration> entry : config.getThreadPoolConfig() .entrySet()) { final HystrixThreadPoolKey threadPoolKey = entry.getKey(); final HystrixThreadPoolConfiguration threadPoolConfig = entry.getValue(); writeThreadPoolConfigJson(json, threadPoolKey, threadPoolConfig); } json.writeEndObject(); json.writeObjectFieldStart("collapsers"); for (Map.Entry<HystrixCollapserKey, HystrixCollapserConfiguration> entry : config.getCollapserConfig() .entrySet()) { final HystrixCollapserKey collapserKey = entry.getKey(); final HystrixCollapserConfiguration collapserConfig = entry.getValue(); writeCollapserConfigJson(json, collapserKey, collapserConfig); } json.writeEndObject(); json.writeEndObject(); json.close(); return jsonString.getBuffer().toString(); } /** * @deprecated Not for public use. Using the delay param prevents streams from being efficiently shared. * Please use {@link HystrixConfigurationStream#observe()} * @param delay interval between data emissions * @return sampled utilization as Java object, taken on a timer */ @Deprecated //deprecated in 1.5.4 public Observable<HystrixConfiguration> observe(int delay) { return streamGenerator.call(delay); } /** * @deprecated Not for public use. Using the delay param prevents streams from being efficiently shared. * Please use {@link HystrixConfigurationStream#observe()} * and you can map to JSON string via {@link HystrixConfigurationJsonStream#convertToString(HystrixConfiguration)} * @param delay interval between data emissions * @return sampled utilization as JSON string, taken on a timer */ @Deprecated //deprecated in 1.5.4 public Observable<String> observeJson(int delay) { return streamGenerator.call(delay).map(convertToJson); } }