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= Thin Clients Overview

== Overview
A thin client is a lightweight Ignite client that connects to the cluster via a standard socket connection.
It does not become a part of the cluster topology, never holds any data, and is not used as a destination for compute grid calculations.
What it does is simply establish a socket connection to a standard Ignite node and perform all operations through that node.

Thin clients are based on the link:binary-client-protocol/binary-client-protocol[binary client protocol], which makes it possible to support Ignite connectivity from any programming language.

Ignite provides the following thin clients:

* link:thin-clients/java-thin-client[Java Thin Client]
* link:thin-clients/dotnet-thin-client[.NET/C# Thin Client]
* link:thin-clients/cpp-thin-client[C++ Thin Client]
* link:thin-clients/python-thin-client[Python Thin Client]
* link:thin-clients/nodejs-thin-client[Node.js Thin Client]
* link:thin-clients/php-thin-client[PHP Thin Client]

////
*TODO: add a diagram of a thin client connecting to the cluster (multiple nodes) and how a request is rerouted to the node that hosts the data*
////

== Thin Client Features
The following table outlines features supported by each client.

:yes: pass:quotes[[.checkmark]#yes#]

[%header,format=csv,cols="2,1,1,1,1,1,1"]
|===
include::thin-client-comparison.csv[]
|===

=== Client Connection Failover

All thin clients support a connection failover mechanism, whereby the client automatically switches to an available node in case of the current node or connection failure.
For this mechanism to work, you need to provide a list of node addresses you want to use for failover purposes in the client configuration.
Refer to the specific client documentation for more details.

[#partition-awareness]
=== Partition Awareness

As explained in the link:data-modeling/data-partitioning[Data Partitioning] section, data in the cluster is distributed between the nodes in a balanced manner for scalability and performance reasons.
Each cluster node maintains a subset of the data and the partition distribution map, which is used to determine the node that keeps the primary/backup copy of requested entries.

include::includes/partition-awareness.adoc[]

Partition Awareness is available for the Java, .NET, C++, Python, and Node.js thin clients.
Refer to the documentation of the specific client for more information.

=== Authentication

All thin clients support authentication in the cluster side. Authentication is link:security/authentication[configured in the cluster] configuration, and the client simply provide user credentials.
Refer to the documentation of the specific client for more information.

== Cluster Configuration

Thin client connection parameters are controlled by the client connector configuration.
By default, Ignite accepts client connections on port 10800.
You can change the port, connection buffer size and timeout, enable SSL/TLS, etc.

=== Configuring Thin Client Connector

The following example shows how to configure thin client connection parameters:

:xmlConfigFile: code-snippets/xml/thin-client-cluster-config.xml
:javaFile: {javaCodeDir}/JavaThinClient.java
:dotnetFile: code-snippets/dotnet/ThinClient.cs

[tabs]
--
tab:XML[]
[source,xml]
----
<bean class="org.apache.ignite.configuration.IgniteConfiguration" id="ignite.cfg">
    <property name="clientConnectorConfiguration">
        <bean class="org.apache.ignite.configuration.ClientConnectorConfiguration">
            <property name="port" value="10000"/>
        </bean>
    </property>
</bean>
----
tab:Java[]
[source,java]
----
include::{javaFile}[tag=clusterConfiguration,indent=0]
----
tab:C#/.NET[]
[source,csharp]
----
include::{dotnetFile}[tag=clusterConfiguration,indent=0]
----
tab:C++[unsupported]
--

The following table describes some parameters that you may want to change.

[cols="1,3,1",opts="header",width="100%"]
|===
| Parameter | Description  | Default Value
| `thinClientEnabled`| Enables or disables thin client connectivity. | `true`
| `port` | The port for thin client connections.  | 10800
| `portRange`| This parameters sets a range of ports for thin client connections. For example, if `portRange` = 10, thin clients can connect to any port from range 10800–18010. The node tries to bind to each port from the range starting from the `port` until it finds an available one. If all ports are unavailable, the node won't start. | 100
| `sslEnabled` | Set this property to `true` to enable SSL for thin client connections.  | `false`
|===

See the complete list of parameters in the link:{javadoc_base_url}/org/apache/ignite/configuration/ClientConnectorConfiguration.html[ClientConnectorConfiguration,window=_blank] javadoc.


=== Enabling SSL/TLS for Thin Clients

Refer to the  link:security/ssl-tls#ssl-for-clients[SSL for Thin Clients and JDBC/ODBC] section.