Java tutorial
/******************************************************************************* * * Copyright 2015 Walmart, 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.oneops.inductor; import static com.oneops.cms.util.CmsConstants.QUEUE_TIME; import static com.oneops.cms.util.CmsConstants.REQUEST_DEQUE_TS; import static com.oneops.cms.util.CmsConstants.REQUEST_ENQUE_TS; import static com.oneops.cms.util.CmsConstants.SEARCH_TS_PATTERN; import static com.oneops.inductor.InductorConstants.ACTION_ORDER_TYPE; import static com.oneops.inductor.InductorConstants.SEARCH_TS_FORMATS; import static com.oneops.inductor.InductorConstants.WORK_ORDER_TYPE; import static org.apache.commons.httpclient.util.DateUtil.formatDate; import static org.apache.commons.httpclient.util.DateUtil.parseDate; import com.codahale.metrics.MetricRegistry; import com.google.gson.Gson; import com.google.gson.stream.JsonReader; import com.oneops.cms.domain.CmsWorkOrderSimpleBase; import com.oneops.cms.execution.Response; import com.oneops.cms.execution.Result; import com.oneops.cms.simple.domain.CmsActionOrderSimple; import com.oneops.cms.simple.domain.CmsWorkOrderSimple; import com.oneops.cms.util.CmsConstants; import java.io.BufferedWriter; import java.io.File; import java.io.IOException; import java.io.StringReader; import java.nio.file.Files; import java.nio.file.Paths; import java.util.Date; import java.util.Map; import java.util.concurrent.Semaphore; import java.util.concurrent.atomic.AtomicInteger; import javax.jms.JMSException; import javax.jms.Message; import javax.jms.MessageListener; import javax.jms.TextMessage; import org.apache.commons.httpclient.util.DateParseException; import org.apache.commons.httpclient.util.DateUtil; import org.apache.log4j.Logger; import org.springframework.beans.BeansException; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.context.ApplicationContext; import org.springframework.context.ApplicationContextAware; import org.springframework.context.support.ClassPathXmlApplicationContext; import org.springframework.jms.listener.DefaultMessageListenerContainer; import org.springframework.stereotype.Component; /** * Listener - consumes from queue by cloud to execute local or remote puppet modules or chef recipes * for work or action orders <p> onMessage is mapped to a Spring ListenerContainer.messageListener */ @Component public class Listener implements MessageListener, ApplicationContextAware { private static final Logger logger = Logger.getLogger(Listener.class); final private Gson gson = new Gson(); private ApplicationContext applicationContext = null; // Number active work orders being processed private AtomicInteger activeThreads = new AtomicInteger(0); private Semaphore semaphore = null; private MessagePublisher messagePublisher = null; private Config config = null; private File dataDir = null; private WorkOrderExecutor workOrderExecutor; private ActionOrderExecutor actionOrderExecutor; private MetricRegistry registry; @Autowired ClassMatchingWoExecutor classMatchingWoExecutor; /** * allow it to run via cmdline */ public static void main(String[] args) { ApplicationContext context = new ClassPathXmlApplicationContext("application-context.xml"); } /** * init - configuration / defaults */ public void init() { dataDir = new File(config.getDataDir()); checkFreeSpace(); logger.info(this); Runtime.getRuntime().addShutdownHook(new Thread(() -> { DefaultMessageListenerContainer listenerContainer = (DefaultMessageListenerContainer) applicationContext .getBean("listenerContainer"); logger.info("Stopping listener container..."); listenerContainer.stop(); while (activeThreads.get() > 0) { logger.info("Shutdown in progress. sleeping for 10sec. activeThreads: " + activeThreads); try { Thread.sleep(10000); } catch (InterruptedException e) { logger.info("Got InterruptedException, but will still let the activeThreads complete."); } } logger.info("Shutdown done."); })); File testDir = new File(dataDir, "../test"); logger.info("Verification test directory created: " + testDir.mkdirs()); } /** * check for free space - shutdownshutdown listener and gracefully exit if full */ @SuppressWarnings("static-access") private void checkFreeSpace() { long freeMB = dataDir.getFreeSpace() / 1024 / 1024; if (freeMB < config.getMinFreeSpaceMB()) { DefaultMessageListenerContainer listenerContainer = (DefaultMessageListenerContainer) applicationContext .getBean("listenerContainer"); logger.info("Stopping listener container due to " + config.getDataDir() + " free space mb: " + freeMB + " ... min_free_space_mb: " + config.getMinFreeSpaceMB()); listenerContainer.stop(); while (activeThreads.get() > 0) { logger.error("Shutdown in progress due " + config.getDataDir() + " free space mb: " + freeMB + " ... min_free_space_mb: " + config.getMinFreeSpaceMB() + ". sleeping for 10sec. activeThreads: " + activeThreads); try { Thread.currentThread().sleep(10000); } catch (InterruptedException e) { logger.info("Got InterruptedException, but will still let the activeThreads complete."); } } Runtime.getRuntime().exit(1); } else { logger.info(config.getDataDir() + " free space mb: " + freeMB); } } /** * for unit test setup */ public void setConfig(Config config) { this.config = config; } /** * MessageListener mapped in application-context.xml - will deserialize to a WorkOrder * (iaas/swdist) or ActionOrder (procedure) * * @param msg Message * @see javax.jms.MessageListener#onMessage(javax.jms.Message) */ public void onMessage(Message msg) { try { checkFreeSpace(); activeThreads.getAndIncrement(); if (msg instanceof TextMessage) { String msgText = ((TextMessage) msg).getText(); final String correlationID = msg.getJMSCorrelationID(); Map<String, String> responseMsgMap; String type = msg.getStringProperty("type"); CmsWorkOrderSimpleBase wo; switch (type) { // WorkOrder case WORK_ORDER_TYPE: { long t = System.currentTimeMillis(); wo = getWorkOrderOf(msgText, CmsWorkOrderSimple.class); wo.putSearchTag("iWoCrtTime", Long.toString(System.currentTimeMillis() - t)); String logKey = workOrderExecutor.getLogKey(wo); logger.info(logKey + " Inductor: " + config.getIpAddr()); preProcess(wo); wo.putSearchTag("rfcAction", wo.getAction()); Response response = runWithMatchingExecutor(wo); if (response == null || response.getResult() == Result.NOT_MATCHED) { responseMsgMap = workOrderExecutor.processAndVerify(wo, correlationID); } else { responseMsgMap = response.getResponseMap(); responseMsgMap.put("correlationID", correlationID); postExecTags(wo); } break; } // ActionOrder case ACTION_ORDER_TYPE: { long t = System.currentTimeMillis(); wo = getWorkOrderOf(msgText, CmsActionOrderSimple.class); wo.putSearchTag("iAoCrtTime", Long.toString(System.currentTimeMillis() - t)); preProcess(wo); responseMsgMap = actionOrderExecutor.processAndVerify(wo, correlationID); break; } default: logger.error(new IllegalArgumentException("Unknown msg type - " + type)); msg.acknowledge(); return; } // Controller will process this message responseMsgMap.put("correlationID", correlationID); responseMsgMap.put("type", type); long startTime = System.currentTimeMillis(); if (!correlationID.equals("test")) { messagePublisher.publishMessage(responseMsgMap); } long endTime = System.currentTimeMillis(); long duration = endTime - startTime; // ack message logger.debug("Send message took:" + duration + "ms"); msg.acknowledge(); } } catch (JMSException | SecurityException | IOException | IllegalArgumentException e) { logger.error("Error occurred in processing message", e); } finally { // Decrement the total number of active threads consumed by 1 activeThreads.getAndDecrement(); clearStateFile(); } } private Response runWithMatchingExecutor(CmsWorkOrderSimpleBase wo) { preExecTags(wo); Response response; if (config.isVerifyMode()) { response = classMatchingWoExecutor.executeAndVerify((CmsWorkOrderSimple) wo, config.getDataDir()); } else { response = classMatchingWoExecutor.execute((CmsWorkOrderSimple) wo, config.getDataDir()); } return response; } private void preProcess(CmsWorkOrderSimpleBase wo) { setStateFile(wo); setQueueTime(wo); } private void preExecTags(CmsWorkOrderSimpleBase wo) { wo.putSearchTag("inductor", config.getIpAddr()); } private void postExecTags(CmsWorkOrderSimpleBase wo) { wo.putSearchTag(CmsConstants.RESPONSE_ENQUE_TS, DateUtil.formatDate(new Date(), SEARCH_TS_PATTERN)); } private CmsWorkOrderSimpleBase getWorkOrderOf(String msgText, Class c) { CmsWorkOrderSimpleBase wo; JsonReader reader = new JsonReader(new StringReader(msgText)); reader.setLenient(true); wo = gson.fromJson(reader, c); return wo; } /** * set state file by thread id */ private void setStateFile(CmsWorkOrderSimpleBase wo) { String filename = getStateFileName(); String content = System.currentTimeMillis() + " " + wo.getClassName() + "::" + wo.getAction() + " " + wo.getNsPath() + System.lineSeparator(); writeStateFile(filename, content); } private String getStateFileName() { return config.getDataDir() + "/state-" + Thread.currentThread().getId(); } /** * clear state file by thread id */ private void clearStateFile() { String filename = getStateFileName(); String content = "idle" + System.lineSeparator(); content += System.currentTimeMillis(); writeStateFile(filename, content); } private void writeStateFile(String filename, String content) { try (BufferedWriter bw = Files.newBufferedWriter(Paths.get(filename))) { bw.write(content); bw.close(); logger.debug("clear state file: " + filename); } catch (IOException e) { logger.error("could not write file: " + filename + " msg:" + e.getMessage()); } } /** * Set the queue time in the wo/ao for search/analytics */ private <T> void setQueueTime(CmsWorkOrderSimpleBase<T> wo) { String totalTime, requestDequeTs; try { requestDequeTs = formatDate(new Date(), SEARCH_TS_PATTERN); wo.putSearchTag(REQUEST_DEQUE_TS, requestDequeTs); totalTime = String.valueOf(getTimeDiff(wo) / 1000.0); wo.getSearchTags().put(QUEUE_TIME, totalTime); } catch (Exception e) { logger.error("Exception occurred while setting queue time " + e); } } private <T> long getTimeDiff(CmsWorkOrderSimpleBase<T> wo) throws DateParseException { String currentDate = formatDate(new Date(), SEARCH_TS_PATTERN); long currentTime = parseDate(currentDate, SEARCH_TS_FORMATS).getTime(); long requestEnqueTime = parseDate(wo.getSearchTags().get(REQUEST_ENQUE_TS), SEARCH_TS_FORMATS).getTime(); return currentTime - requestEnqueTime; } /** * setter for spring to wire the MessagePublisher */ public void setMessagePublisher(MessagePublisher mp) { this.messagePublisher = mp; } public InductorStatus getStatus() { InductorStatus stat = new InductorStatus(); stat.setQueueBacklog(0); stat.setQueueName(config.getInQueue()); return stat; } @Override public void setApplicationContext(ApplicationContext ac) throws BeansException { this.applicationContext = ac; } @Override public String toString() { final StringBuilder sb = new StringBuilder("Inductor{ "); sb.append(config); sb.append(", semaphore=").append(semaphore); sb.append('}'); return sb.toString(); } public void setWorkOrderExecutor(WorkOrderExecutor workOrderExecutor) { this.workOrderExecutor = workOrderExecutor; } public void setActionOrderExecutor(ActionOrderExecutor actionOrderExecutor) { this.actionOrderExecutor = actionOrderExecutor; } public void setRegistry(MetricRegistry registry) { this.registry = registry; } public MetricRegistry getRegistry() { return registry; } }