You can use the Java client in multiple ways:
Obtaining an elasticsearch
Client is simple. The most common way to
get a client is by:
Creating an embedded
Nodethat acts as a node within a cluster.
Clientfrom your embedded
Another manner is by creating a
that connects to a cluster.
Please note that you are encouraged to use the same version on client and cluster sides. You may hit some incompatibility issues when mixing major versions.
Instantiating a node based client is the simplest way to get a
that can execute operations against elasticsearch.
import static org.elasticsearch.node.NodeBuilder.*; // on startup Node node = nodeBuilder().node(); Client client = node.client(); // on shutdown node.close();
When you start a
Node, it joins an elasticsearch cluster. You can have
different clusters by simply setting the
cluster.name setting, or
explicitly using the
clusterName method on the builder.
You can define
cluster.name in the
file in your project. As long as
elasticsearch.yml is present in the
classpath, it will be used when you start your node.
Or in Java:
Node node = nodeBuilder().clusterName("yourclustername").node(); Client client = node.client();
The benefit of using the
Client is the fact that operations are
automatically routed to the node(s) the operations need to be executed
on, without performing a "double hop". For example, the index operation
will automatically be executed on the shard that it will end up existing
When you start a
Node, the most important decision is whether it
should hold data or not. In other words, should indices and shards be
allocated to it. Many times we would like to have the clients just be
clients, without shards being allocated to them. This is simple to
configure by setting either
node.data setting to
NodeBuilder respective helper methods on
import static org.elasticsearch.node.NodeBuilder.*; // on startup Node node = nodeBuilder().client(true).node(); Client client = node.client(); // on shutdown node.close();
Another common usage is to start the
Node and use the
unit/integration tests. In such a case, we would like to start a "local"
Node (with a "local" discovery and transport). Again, this is just a
matter of a simple setting when starting the
Node. Note, "local" here
means local on the JVM (well, actually class loader) level, meaning that
two local servers started within the same JVM will discover themselves
and form a cluster.
import static org.elasticsearch.node.NodeBuilder.*; // on startup Node node = nodeBuilder().local(true).node(); Client client = node.client(); // on shutdown node.close();
TransportClient connects remotely to an elasticsearch cluster
using the transport module. It does not join the cluster, but simply
gets one or more initial transport addresses and communicates with them
in round robin fashion on each action (though most actions will probably
be "two hop" operations).
// on startup Client client = new TransportClient() .addTransportAddress(new InetSocketTransportAddress("host1", 9300)) .addTransportAddress(new InetSocketTransportAddress("host2", 9300)); // on shutdown client.close();
Note that you have to set the cluster name if you use one different than "elasticsearch":
Settings settings = ImmutableSettings.settingsBuilder() .put("cluster.name", "myClusterName").build(); Client client = new TransportClient(settings); //Add transport addresses and do something with the client...
elasticsearch.yml file as shown in the Node
The client allows to sniff the rest of the cluster, and add those into
its list of machines to use. In this case, note that the IP addresses
used will be the ones that the other nodes were started with (the
"publish" address). In order to enable it, set the
Settings settings = ImmutableSettings.settingsBuilder() .put("client.transport.sniff", true).build(); TransportClient client = new TransportClient(settings);
Other transport client level settings include:
The time to wait for a ping response
from a node. Defaults to
How often to sample / ping
the nodes listed and connected. Defaults to