Examples with Transition org.apache.helix.participant.statemachine.Transition used on opensource projects

Example 1 with Transition

use of org.apache.helix.participant.statemachine.Transition in project helix by apache.

the class TaskStateModel method onBecomeOnlineFromOffline.

@Transition(to = "ONLINE", from = "OFFLINE")
public void onBecomeOnlineFromOffline(Message message, NotificationContext context) throws Exception {
    LOG.debug(_workerId + " becomes ONLINE from OFFLINE for " + _partition);
    ConfigAccessor clusterConfig = context.getManager().getConfigAccessor();
    HelixManager manager = context.getManager();
    HelixConfigScope clusterScope = new HelixConfigScopeBuilder(ConfigScopeProperty.CLUSTER).forCluster(manager.getClusterName()).build();
    String json = clusterConfig.get(clusterScope, message.getResourceName());
    Dag.Node node = Dag.Node.fromJson(json);
    Set<String> parentIds = node.getParentIds();
    String resourceName = message.getResourceName();
    int numPartitions = node.getNumPartitions();
    Task task = _taskFactory.createTask(resourceName, parentIds, manager, _taskResultStore);
    manager.addExternalViewChangeListener(task);
    LOG.debug("Starting task for " + _partition + "...");
    int partitionNum = Integer.parseInt(_partition.split("_")[1]);
    task.execute(resourceName, numPartitions, partitionNum);
    LOG.debug("Task for " + _partition + " done");
}

Example 2 with Transition

use of org.apache.helix.participant.statemachine.Transition in project helix by apache.

the class FileStoreStateModel method onBecomeMasterFromSlave.

/**
 * When the node becomes master, it will start accepting writes and increments
 * the epoch and starts logging the changes in a file
 * @param message
 * @param context
 * @throws Exception
 */
@Transition(from = "SLAVE", to = "MASTER")
public void onBecomeMasterFromSlave(final Message message, NotificationContext context) throws Exception {
    replicator.stop();
    System.out.println(_serverId + " transitioning from " + message.getFromState() + " to " + message.getToState() + " for " + _partition);
    ZkHelixPropertyStore<ZNRecord> helixPropertyStore = context.getManager().getHelixPropertyStore();
    String checkpointDirPath = instanceConfig.getRecord().getSimpleField("check_point_dir");
    CheckpointFile checkpointFile = new CheckpointFile(checkpointDirPath);
    final ChangeRecord lastRecordProcessed = checkpointFile.findLastRecordProcessed();
    DataUpdater<ZNRecord> updater = new HighWaterMarkUpdater(message, lastRecordProcessed);
    helixPropertyStore.update("/TRANSACTION_ID_METADATA" + "/" + message.getResourceName(), updater, AccessOption.PERSISTENT);
    Stat stat = new Stat();
    ;
    ZNRecord znRecord = helixPropertyStore.get("/TRANSACTION_ID_METADATA" + "/" + message.getResourceName(), stat, AccessOption.PERSISTENT);
    int startGen = Integer.parseInt(znRecord.getSimpleField("currentGen"));
    int startSeq = Integer.parseInt(znRecord.getSimpleField("currentGenStartSeq"));
    String fileStoreDir = instanceConfig.getRecord().getSimpleField("file_store_dir");
    String changeLogDir = instanceConfig.getRecord().getSimpleField("change_log_dir");
    generator = new ChangeLogGenerator(changeLogDir, startGen, startSeq);
    // To indicate that we need callbacks for changes that happen starting now
    long now = System.currentTimeMillis();
    service = new FileSystemWatchService(fileStoreDir, now, generator);
    service.start();
    System.out.println(_serverId + " transitioned from " + message.getFromState() + " to " + message.getToState() + " for " + _partition);
}

Example 3 with Transition

use of org.apache.helix.participant.statemachine.Transition in project helix by apache.

the class GenericLeaderStandbyModel method onBecomeLeaderFromStandby.

@Transition(to = "LEADER", from = "STANDBY")
public void onBecomeLeaderFromStandby(Message message, NotificationContext context) throws Exception {
    LOG.info("Become LEADER from STANDBY");
    HelixManager manager = context.getManager();
    if (manager == null) {
        throw new IllegalArgumentException("Require HelixManager in notification conext");
    }
    for (ChangeType notificationType : _notificationTypes) {
        if (notificationType == ChangeType.LIVE_INSTANCE) {
            manager.addLiveInstanceChangeListener(_particHolder);
        } else if (notificationType == ChangeType.CONFIG) {
            manager.addConfigChangeListener(_particHolder);
        } else if (notificationType == ChangeType.EXTERNAL_VIEW) {
            manager.addExternalViewChangeListener(_particHolder);
        } else {
            LOG.error("Unsupport notificationType:" + notificationType.toString());
        }
    }
}

Example 4 with Transition

use of org.apache.helix.participant.statemachine.Transition in project helix by apache.

the class GenericLeaderStandbyModel method onBecomeStandbyFromLeader.

@Transition(to = "STANDBY", from = "LEADER")
public void onBecomeStandbyFromLeader(Message message, NotificationContext context) {
    LOG.info("Become STANDBY from LEADER");
    HelixManager manager = context.getManager();
    if (manager == null) {
        throw new IllegalArgumentException("Require HelixManager in notification conext");
    }
    Builder keyBuilder = new Builder(manager.getClusterName());
    for (ChangeType notificationType : _notificationTypes) {
        if (notificationType == ChangeType.LIVE_INSTANCE) {
            manager.removeListener(keyBuilder.liveInstances(), _particHolder);
        } else if (notificationType == ChangeType.CONFIG) {
            manager.removeListener(keyBuilder.instanceConfigs(), _particHolder);
        } else if (notificationType == ChangeType.EXTERNAL_VIEW) {
            manager.removeListener(keyBuilder.externalViews(), _particHolder);
        } else {
            LOG.error("Unsupport notificationType:" + notificationType.toString());
        }
    }
}

Example 5 with Transition

use of org.apache.helix.participant.statemachine.Transition in project helix by apache.

the class AgentStateModel method genericStateTransitionHandler.

@Transition(to = "*", from = "*")
public void genericStateTransitionHandler(Message message, NotificationContext context) throws Exception {
    // first try get command from message
    String cmd = message.getRecord().getSimpleField(CommandAttribute.COMMAND.getName());
    String workingDir = message.getRecord().getSimpleField(CommandAttribute.WORKING_DIR.getName());
    String timeout = message.getRecord().getSimpleField(CommandAttribute.TIMEOUT.getName());
    String pidFile = message.getRecord().getSimpleField(CommandAttribute.PID_FILE.getName());
    HelixManager manager = context.getManager();
    String clusterName = manager.getClusterName();
    String fromState = message.getFromState();
    String toState = message.getToState();
    // construct keys for command-config
    String cmdKey = buildKey(fromState, toState, CommandAttribute.COMMAND);
    String workingDirKey = buildKey(fromState, toState, CommandAttribute.WORKING_DIR);
    String timeoutKey = buildKey(fromState, toState, CommandAttribute.TIMEOUT);
    String pidFileKey = buildKey(fromState, toState, CommandAttribute.PID_FILE);
    List<String> cmdConfigKeys = Arrays.asList(cmdKey, workingDirKey, timeoutKey, pidFileKey);
    // read command from resource-scope configures
    if (cmd == null) {
        HelixConfigScope resourceScope = new HelixConfigScopeBuilder(ConfigScopeProperty.RESOURCE).forCluster(clusterName).forResource(message.getResourceName()).build();
        Map<String, String> cmdKeyValueMap = manager.getConfigAccessor().get(resourceScope, cmdConfigKeys);
        if (cmdKeyValueMap != null) {
            cmd = cmdKeyValueMap.get(cmdKey);
            workingDir = cmdKeyValueMap.get(workingDirKey);
            timeout = cmdKeyValueMap.get(timeoutKey);
            pidFile = cmdKeyValueMap.get(pidFileKey);
        }
    }
    // if resource-scope doesn't contain command, fall back to cluster-scope configures
    if (cmd == null) {
        HelixConfigScope clusterScope = new HelixConfigScopeBuilder(ConfigScopeProperty.CLUSTER).forCluster(clusterName).build();
        Map<String, String> cmdKeyValueMap = manager.getConfigAccessor().get(clusterScope, cmdConfigKeys);
        if (cmdKeyValueMap != null) {
            cmd = cmdKeyValueMap.get(cmdKey);
            workingDir = cmdKeyValueMap.get(workingDirKey);
            timeout = cmdKeyValueMap.get(timeoutKey);
            pidFile = cmdKeyValueMap.get(pidFileKey);
        }
    }
    if (cmd == null) {
        throw new Exception("Unable to find command for transition from:" + message.getFromState() + " to:" + message.getToState());
    }
    _logger.info("Executing command: " + cmd + ", using workingDir: " + workingDir + ", timeout: " + timeout + ", on " + manager.getInstanceName());
    // skip nop command
    if (cmd.equals(CommandAttribute.NOP.getName())) {
        return;
    }
    // split the cmd to actual cmd and args[]
    String[] cmdSplits = cmd.trim().split("\\s+");
    String cmdValue = cmdSplits[0];
    String[] args = Arrays.copyOfRange(cmdSplits, 1, cmdSplits.length);
    // get the command-execution timeout
    // 0 means wait for ever
    long timeoutValue = 0;
    if (timeout != null) {
        try {
            timeoutValue = Long.parseLong(timeout);
        } catch (NumberFormatException e) {
        // OK to use 0
        }
    }
    ExternalCommand externalCmd = ExternalCommand.executeWithTimeout(new File(workingDir), cmdValue, timeoutValue, args);
    int exitValue = externalCmd.exitValue();
    if (_logger.isDebugEnabled()) {
        _logger.debug("command: " + cmd + ", exitValue: " + exitValue + " output:\n" + externalCmd.getStringOutput());
    }
    // monitor pid if pidFile exists
    if (pidFile == null) {
        // no pid to monitor
        return;
    }
    String pidFileValue = instantiateByMessage(pidFile, message);
    String pid = SystemUtil.getPidFromFile(new File(pidFileValue));
    if (pid != null) {
        new ProcessMonitorThread(pid).start();
    }
}