How to use

getRack

method

in

com.datastax.driver.core.Host

/**
 * {@inheritDoc}
 */
@Override
public synchronized Session connect() throws NoHostAvailableException {
  if (isDisconnected()) {
    LOG.info("Connected to cluster: {}", cluster.getClusterName());
    for (Host host : getAllHosts())
      LOG.info("Datacenter: {}; Host: {}; Rack: {}", host.getDatacenter(), host.getAddress(), host.getRack());
    LOG.info("Connect to cluster using keyspace %s", keyspace);
    session = cluster.connect(keyspace);
  } else {
    LOG.warn("{} - Already connected to cluster: {}", getExecutorName(), cluster.getClusterName());
  }
  if (session.isClosed()) {
    LOG.warn("Session has been closed - create new one!");
    this.session = cluster.newSession();
  }
  return session;
}

  @Override
  public Cluster get() {
    String host = configuration.getHostAddress();
    int port = configuration.getPort();

    LOGGER.info("Connecting to cassandra cluster with host:{}, port:{}", host, port);

    Cluster cluster = Cluster.builder()
        .addContactPoint(host)
        .withPort(port)
        .build();

    Metadata metadata = cluster.getMetadata();
    LOGGER.info("Connected to cluster: {}", metadata.getClusterName());
    metadata.getAllHosts().forEach(h -> {
      LOGGER.info("Datacenter:{}, host:{}, rack: {}", h.getDatacenter(), h.getAddress(), h.getRack());
    });
    return cluster;
  }
}

logger.info("Datacenter: {}; Host: {}; Rack: {}\n",
  discoveredHost.getDatacenter(), discoveredHost.getAddress(),
  discoveredHost.getRack());

private Map<String, Set<String>> getRacksInDcs(Iterable<Host> hosts) {
 Map<String, Set<String>> result = new HashMap<String, Set<String>>();
 for (Host host : hosts) {
  Set<String> racks = result.get(host.getDatacenter());
  if (racks == null) {
   racks = new HashSet<String>();
   result.put(host.getDatacenter(), racks);
  }
  racks.add(host.getRack());
 }
 return result;
}

if (rf == null || dcReplicas.size() >= rf) continue;
String rack = h.getRack();

private static void updateLocationInfo(
  Host host,
  String datacenter,
  String rack,
  boolean isInitialConnection,
  Cluster.Manager cluster) {
 if (MoreObjects.equal(host.getDatacenter(), datacenter)
   && MoreObjects.equal(host.getRack(), rack)) return;
 // If the dc/rack information changes for an existing node, we need to update the load balancing
 // policy.
 // For that, we remove and re-add the node against the policy. Not the most elegant, and assumes
 // that the policy will update correctly, but in practice this should work.
 if (!isInitialConnection) cluster.loadBalancingPolicy().onDown(host);
 host.setLocationInfo(datacenter, rack);
 if (!isInitialConnection) cluster.loadBalancingPolicy().onAdd(host);
}

private Map<String, Set<String>> getRacksInDcs(Iterable<Host> hosts) {
  Map<String, Set<String>> result = new HashMap<String, Set<String>>();
  for (Host host : hosts) {
    Set<String> racks = result.get(host.getDatacenter());
    if (racks == null) {
      racks = new HashSet<String>();
      result.put(host.getDatacenter(), racks);
    }
    racks.add(host.getRack());
  }
  return result;
}

private Map<String, Set<String>> getRacksInDcs(Iterable<Host> hosts) {
  Map<String, Set<String>> result = new HashMap<String, Set<String>>();
  for (Host host : hosts) {
    Set<String> racks = result.get(host.getDatacenter());
    if (racks == null) {
      racks = new HashSet<String>();
      result.put(host.getDatacenter(), racks);
    }
    racks.add(host.getRack());
  }
  return result;
}

private Map<String, Set<String>> getRacksInDcs(Iterable<Host> hosts) {
  Map<String, Set<String>> result = new HashMap<String, Set<String>>();
  for (Host host : hosts) {
    Set<String> racks = result.get(host.getDatacenter());
    if (racks == null) {
      racks = new HashSet<String>();
      result.put(host.getDatacenter(), racks);
    }
    racks.add(host.getRack());
  }
  return result;
}

private RingMember(Host host) {
  Assert.notNull(host, "Host must not be null");
  this.hostName = host.getAddress().getHostName();
  this.address = host.getAddress().getHostAddress();
  this.dc = host.getDatacenter();
  this.rack = host.getRack();
}

public RingMember(Host h) {
  this.hostName = h.getAddress().getHostName();
  this.address = h.getAddress().getHostAddress();
  this.DC = h.getDatacenter();
  this.rack = h.getRack();
}

host.getDatacenter(),
host.getAddress(),
host.getRack());

private void displayClusterInfo() {
  Metadata metadata = m_cluster.getMetadata();
  m_logger.info("Connected to cluster with topography:");
  RoundRobinPolicy policy = new RoundRobinPolicy();
  for (Host host : metadata.getAllHosts()) {
    m_logger.info("   Host {}: datacenter: {}, rack: {}, distance: {}",
           new Object[]{host.getAddress(), host.getDatacenter(), 
      host.getRack(), policy.distance(host)});
  }
  m_logger.info("Database contains {} keyspaces", metadata.getKeyspaces().size());
}   // displayClusterInfo

private void displayClusterInfo() {
  Metadata metadata = m_cluster.getMetadata();
  m_logger.info("Connected to cluster with topography:");
  RoundRobinPolicy policy = new RoundRobinPolicy();
  for (Host host : metadata.getAllHosts()) {
    m_logger.info("   Host {}: datacenter: {}, rack: {}, distance: {}",
           new Object[]{host.getAddress(), host.getDatacenter(), 
      host.getRack(), policy.distance(host)});
  }
  m_logger.info("Database contains {} keyspaces", metadata.getKeyspaces().size());
}   // displayClusterInfo

private static void updateLocationInfo(Host host, String datacenter, String rack, Cluster.Manager cluster) {
  if (Objects.equal(host.getDatacenter(), datacenter) && Objects.equal(host.getRack(), rack))
    return;
  // If the dc/rack information changes, we need to update the load balancing policy.
  // For that, we remove and re-add the node against the policy. Not the most elegant, and assumes
  // that the policy will update correctly, but in practice this should work.
  cluster.loadBalancingPolicy().onDown(host);
  host.setLocationInfo(datacenter, rack);
  cluster.loadBalancingPolicy().onAdd(host);
}

private Host parseHostInfo(ResultSet rs) {
  
  if (rs == null) {
    return null;
  }
  
  com.datastax.driver.core.Host fromHost = rs.getExecutionInfo().getQueriedHost();
  InetAddress add = fromHost.getAddress();
  
  Host toHost = new Host(add.getHostAddress(), -1);
  toHost.setRack(fromHost.getRack());
  return toHost;
}

public void connect(String node) {
  cluster = Cluster.builder().addContactPoint(node).build();
  Metadata metadata = cluster.getMetadata();
  System.out.printf("Connected to cluster: %s\n", metadata.getClusterName());
  for (Host host : metadata.getAllHosts()) {
    System.out.printf("Datatacenter: %s; Host: %s; Rack: %s\n", host.getDatacenter(), host.getAddress(), host.getRack());
  }
  session = cluster.connect("karaf_demo");
}

private static void updateLocationInfo(Host host, String datacenter, String rack, boolean isInitialConnection, Cluster.Manager cluster) {
  if (Objects.equal(host.getDatacenter(), datacenter) && Objects.equal(host.getRack(), rack))
    return;
  // If the dc/rack information changes for an existing node, we need to update the load balancing policy.
  // For that, we remove and re-add the node against the policy. Not the most elegant, and assumes
  // that the policy will update correctly, but in practice this should work.
  if (!isInitialConnection)
    cluster.loadBalancingPolicy().onDown(host);
  host.setLocationInfo(datacenter, rack);
  if (!isInitialConnection)
    cluster.loadBalancingPolicy().onAdd(host);
}

private static void updateLocationInfo(Host host, String datacenter, String rack, boolean isInitialConnection, Cluster.Manager cluster) {
  if (MoreObjects.equal(host.getDatacenter(), datacenter) && MoreObjects.equal(host.getRack(), rack))
    return;
  // If the dc/rack information changes for an existing node, we need to update the load balancing policy.
  // For that, we remove and re-add the node against the policy. Not the most elegant, and assumes
  // that the policy will update correctly, but in practice this should work.
  if (!isInitialConnection)
    cluster.loadBalancingPolicy().onDown(host);
  host.setLocationInfo(datacenter, rack);
  if (!isInitialConnection)
    cluster.loadBalancingPolicy().onAdd(host);
}

private static void updateLocationInfo(Host host, String datacenter, String rack, boolean isInitialConnection, Cluster.Manager cluster) {
  if (Objects.equal(host.getDatacenter(), datacenter) && Objects.equal(host.getRack(), rack))
    return;
  // If the dc/rack information changes for an existing node, we need to update the load balancing policy.
  // For that, we remove and re-add the node against the policy. Not the most elegant, and assumes
  // that the policy will update correctly, but in practice this should work.
  if (!isInitialConnection)
    cluster.loadBalancingPolicy().onDown(host);
  host.setLocationInfo(datacenter, rack);
  if (!isInitialConnection)
    cluster.loadBalancingPolicy().onAdd(host);
}