public abstract class DelegatingCluster extends Cluster
Cluster implementations that wrap another instance (delegate / decorator pattern).Cluster.Builder, Cluster.Initializer| Modifier | Constructor and Description |
|---|---|
protected |
DelegatingCluster()
Builds a new instance.
|
| Modifier and Type | Method and Description |
|---|---|
void |
close()
Initiates a shutdown of this cluster instance and blocks until
that shutdown completes.
|
CloseFuture |
closeAsync()
Initiates a shutdown of this cluster instance.
|
Session |
connect()
Creates a new session on this cluster and initialize it.
|
Session |
connect(String keyspace)
Creates a new session on this cluster, initialize it and sets the
keyspace to the provided one.
|
ListenableFuture<Session> |
connectAsync()
Creates a new session on this cluster and initializes it asynchronously.
|
ListenableFuture<Session> |
connectAsync(String keyspace)
Creates a new session on this cluster, and initializes it to the given
keyspace asynchronously.
|
protected abstract Cluster |
delegate()
Returns the delegate instance where all calls will be forwarded.
|
Configuration |
getConfiguration()
The cluster configuration.
|
Metadata |
getMetadata()
Returns read-only metadata on the connected cluster.
|
Metrics |
getMetrics()
The cluster metrics.
|
Cluster |
init()
Initialize this Cluster instance.
|
boolean |
isClosed()
Whether this Cluster instance has been closed.
|
Session |
newSession()
Creates a new session on this cluster but does not initialize it.
|
Cluster |
register(Host.StateListener listener)
Registers the provided listener to be notified on hosts
up/down/added/removed events.
|
Cluster |
register(LatencyTracker tracker)
Registers the provided tracker to be updated with hosts read
latencies.
|
Cluster |
unregister(Host.StateListener listener)
Unregisters the provided listener from being notified on hosts events.
|
Cluster |
unregister(LatencyTracker tracker)
Unregisters the provided latency tracking from being updated
with host read latencies.
|
builder, buildFrom, getClusterName, getDriverVersion, register, unregisterprotected abstract Cluster delegate()
public Cluster init()
ClusterCluster instance. That connection is then
used to populate the cluster Metadata.
Calling this method is optional in the sense that any call to one of the
connect methods of this object will automatically trigger a call
to this method beforehand. It is thus only useful to call this method if
for some reason you want to populate the metadata (or test that at least
one contact point can be reached) without creating a first Session.
Please note that this method only creates one control connection for
gathering cluster metadata. In particular, it doesn't create any connection pools.
Those are created when a new Session is created through
connect.
This method has no effect if the cluster is already initialized.public Session newSession()
ClusterSession.init() method is
called explicitly, or whenever the returned session object is used.
Once a session returned by this method gets initialized (see above), it
will be set to no keyspace. If you want to set such session to a
keyspace, you will have to explicitly execute a 'USE mykeyspace' query.
Note that if you do not particularly need to defer initialization, it is
simpler to use one of the connect() method of this class.newSession in class Clusterpublic Session connect()
ClusterCluster.newSession().public Session connect(String keyspace)
ClusterCluster.newSession().public ListenableFuture<Session> connectAsync()
ClusterCluster if needed; note that cluster
initialization happens synchronously on the thread that called this method.
Therefore it is recommended to initialize the cluster at application
startup, and not rely on this method to do it.connectAsync in class ClusterCluster.connect()public ListenableFuture<Session> connectAsync(String keyspace)
ClusterCluster if needed; note that cluster
initialization happens synchronously on the thread that called this method.
Therefore it is recommended to initialize the cluster at application
startup, and not rely on this method to do it.connectAsync in class Clusterkeyspace - The name of the keyspace to use for the created
Session.public Metadata getMetadata()
Clusterinit() nor connect()
has been called yet).getMetadata in class Clusterpublic Configuration getConfiguration()
ClustergetConfiguration in class Clusterpublic Metrics getMetrics()
ClustergetMetrics in class Clusternull if this cluster has not yet been initialized, or if
metrics collection has been disabled (that is if Configuration.getMetricsOptions() returns null).public Cluster register(Host.StateListener listener)
ClusterLoadBalancingPolicy implements
Host.StateListener, the configured load balancing does not
need to (and should not) be registered through this method to
received host related events.register in class Clusterlistener - the new Host.StateListener to register.Cluster object;public Cluster unregister(Host.StateListener listener)
Clusterlistener hadn't previously be
registered against this Cluster.unregister in class Clusterlistener - the Host.StateListener to unregister.Cluster object;public Cluster register(LatencyTracker tracker)
Clusterupdate method will be call
very frequently (at the end of every query to a Cassandra host) and
should thus not be costly.
The main use case for a LatencyTracker is so
LoadBalancingPolicy can implement latency awareness
Typically, LatencyAwarePolicy registers it's own internal
LatencyTracker (automatically, you don't have to call this
method directly).register in class Clustertracker - the new LatencyTracker to register.Cluster object;public Cluster unregister(LatencyTracker tracker)
Clustertracker hadn't previously be
registered against this Cluster.unregister in class Clustertracker - the LatencyTracker to unregister.Cluster object;public CloseFuture closeAsync()
ClusterCloseFuture.force() can be called on the result future.
This method has no particular effect if the cluster was already closed
(in which case the returned future will return immediately).closeAsync in class Clusterpublic void close()
ClustercloseAsync().get().public boolean isClosed()
ClusterCluster.closeAsync() or Cluster.close()) has been called, it does not guarantee
that the closing is done. If you want to guarantee that the closing is done,
you can call close() and wait until it returns (or call the get method
on closeAsync() with a very short timeout and check this doesn't timeout).