Java tutorial
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See the License for the * specific language governing permissions and limitations * under the License. * */ package org.apache.airavata.common.utils; import org.apache.airavata.common.exception.ApplicationSettingsException; import org.apache.curator.framework.CuratorFramework; import org.apache.zookeeper.WatchedEvent; import org.apache.zookeeper.Watcher; import org.apache.zookeeper.data.Stat; import org.apache.zookeeper.server.ServerCnxnFactory; import org.apache.zookeeper.server.ServerConfig; import org.apache.zookeeper.server.ZooKeeperServer; import org.apache.zookeeper.server.persistence.FileTxnSnapLog; import org.apache.zookeeper.server.quorum.QuorumPeerConfig; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import java.io.File; import java.io.IOException; import java.net.URL; import java.nio.ByteBuffer; public class AiravataZKUtils implements Watcher { private final static Logger logger = LoggerFactory.getLogger(AiravataZKUtils.class); public static final String ZK_EXPERIMENT_STATE_NODE = "state"; public static final String DELIVERY_TAG_POSTFIX = "-deliveryTag"; public static final String CANCEL_DELIVERY_TAG_POSTFIX = "-cancel-deliveryTag"; @Override public void process(WatchedEvent event) { } public static String getExpZnodePath(String experimentId) throws ApplicationSettingsException { return "/experiments" + File.separator + ServerSettings.getGFacServerName() + File.separator + experimentId; } public static String getExpZnodeHandlerPath(String experimentId, String className) throws ApplicationSettingsException { return "/experiments" + File.separator + ServerSettings.getGFacServerName() + File.separator + experimentId + File.separator + className; } public static String getZKhostPort() throws ApplicationSettingsException { return ServerSettings.getZookeeperConnection(); } public static int getZKTimeout() throws ApplicationSettingsException { return ServerSettings.getZookeeperTimeout(); } public static String getExpStatePath(String experimentId) throws ApplicationSettingsException { return AiravataZKUtils.getExpZnodePath(experimentId) + File.separator + "state"; } public static String getExpState(CuratorFramework curatorClient, String expId) throws Exception { Stat exists = curatorClient.checkExists().forPath(getExpStatePath(expId)); if (exists != null) { return new String(curatorClient.getData().storingStatIn(exists).forPath(getExpStatePath(expId))); } return null; } public static void runZKFromConfig(ServerConfig config, ServerCnxnFactory cnxnFactory) throws IOException { AiravataZKUtils.logger.info("Starting Zookeeper server..."); FileTxnSnapLog txnLog = null; try { // Note that this thread isn't going to be doing anything else, // so rather than spawning another thread, we will just call // run() in this thread. // create a file logger url from the command line args ZooKeeperServer zkServer = new ZooKeeperServer(); txnLog = new FileTxnSnapLog(new File(config.getDataDir()), new File(config.getDataDir())); zkServer.setTxnLogFactory(txnLog); zkServer.setTickTime(config.getTickTime()); zkServer.setMinSessionTimeout(config.getMinSessionTimeout()); zkServer.setMaxSessionTimeout(config.getMaxSessionTimeout()); cnxnFactory = ServerCnxnFactory.createFactory(); cnxnFactory.configure(config.getClientPortAddress(), config.getMaxClientCnxns()); cnxnFactory.startup(zkServer); cnxnFactory.join(); if (zkServer.isRunning()) { zkServer.shutdown(); } } catch (InterruptedException e) { // warn, but generally this is ok AiravataZKUtils.logger.warn("Server interrupted", e); System.exit(1); } finally { if (txnLog != null) { txnLog.close(); } } } public static void startEmbeddedZK(ServerCnxnFactory cnxnFactory) { if (ServerSettings.isEmbeddedZK()) { ServerConfig serverConfig = new ServerConfig(); URL resource = AiravataZKUtils.class.getClassLoader().getResource("zoo.cfg"); if (resource == null) { logger.error("There is no zoo.cfg file in the classpath... Failed to start Zookeeper Server"); System.exit(1); } try { serverConfig.parse(resource.getPath()); } catch (QuorumPeerConfig.ConfigException e) { logger.error("Error while starting embedded Zookeeper", e); System.exit(2); } final ServerConfig fServerConfig = serverConfig; final ServerCnxnFactory fserverCnxnFactory = cnxnFactory; (new Thread() { public void run() { try { AiravataZKUtils.runZKFromConfig(fServerConfig, fserverCnxnFactory); } catch (IOException e) { logger.error("Error while starting embedded Zookeeper", e); System.exit(3); } } }).start(); } else { logger.info("Skipping Zookeeper embedded startup ..."); } } public static byte[] toByteArray(double value) { byte[] bytes = new byte[8]; ByteBuffer.wrap(bytes).putDouble(value); return bytes; } public static long getDeliveryTag(String experimentID, CuratorFramework curatorClient, String experimentNode, String pickedChild) throws Exception { String deliveryTagPath = experimentNode + File.separator + pickedChild + File.separator + experimentID + DELIVERY_TAG_POSTFIX; Stat exists = curatorClient.checkExists().forPath(deliveryTagPath); if (exists == null) { logger.error("Cannot find delivery Tag in path:" + deliveryTagPath + " for this experiment"); return -1; } return bytesToLong(curatorClient.getData().storingStatIn(exists).forPath(deliveryTagPath)); } public static byte[] longToBytes(long x) { ByteBuffer buffer = ByteBuffer.allocate(Long.BYTES); buffer.putLong(x); return buffer.array(); } public static long bytesToLong(byte[] bytes) { ByteBuffer buffer = ByteBuffer.allocate(Long.BYTES); buffer.put(bytes); buffer.flip();//need flip return buffer.getLong(); } public static double toDouble(byte[] bytes) { return ByteBuffer.wrap(bytes).getDouble(); } public static long getCancelDeliveryTagIfExist(String experimentId, CuratorFramework curatorClient, String experimentNode, String pickedChild) throws Exception { String cancelDeliveryTagPath = experimentNode + File.separator + pickedChild + File.separator + experimentId + AiravataZKUtils.CANCEL_DELIVERY_TAG_POSTFIX; Stat exists = curatorClient.checkExists().forPath(cancelDeliveryTagPath); if (exists == null) { return -1; // no cancel deliverytag found } else { return bytesToLong(curatorClient.getData().storingStatIn(exists).forPath(cancelDeliveryTagPath)); } } }