Java Client

Add the GridGain 9 Java client to a project, connect to a cluster, authenticate, configure logging, and read client connection metrics.

GridGain 9 clients connect to the cluster via a standard socket connection. Unlike GridGain 8, there is no separate Thin and Thick clients in GridGain 9. All clients are 'thin'.

Clients do not become a part of the cluster topology, never hold any data, and are not used as a destination for compute calculations.

Getting Started

Prerequisites

GridGain is tested on Oracle JDK 11, 17, 21, and 25 (LTS), as well as JDK 26 (STS). Other Java vendors are supported, but may have minor discrepancies in performance or stability.

Short-term support (STS) Java versions are supported only until the next STS release, Long-term support (LTS) versions are not affected by this policy.

Installation

Java client can be added to your project by using GridGain maven repository:

• Add GridGain repository to your project:

<repositories>
    <repository>
        <id>GridGain External Repository</id>
        <url>https://www.gridgainsystems.com/nexus/content/repositories/external</url>
    </repository>
</repositories>

• Add the GridGain client dependency

<dependency>
    <groupId>org.gridgain</groupId>
    <artifactId>ignite-client</artifactId>
    <version>9.1</version>
</dependency>

Connecting to Cluster

To initialize a client, use the IgniteClient class:

Java

try (org.apache.ignite.client.IgniteClient client = org.apache.ignite.client.IgniteClient.builder()
        .addresses("127.0.0.1:10800")
        .build()
) {
    client.sql().execute(null, "CREATE SEQUENCE IF NOT EXISTS Person;");
}

Authentication

To pass authentication information, use the IgniteClientAuthenticator class and pass it to IgniteClient builder:

Java

IgniteClientAuthenticator auth = BasicAuthenticator.builder().username("myUser").password("myPassword").build();

try (IgniteClient client = IgniteClient.builder()
        .addresses("127.0.0.1:10800")
        .authenticator(auth)
        .build()
) {
    client.sql().execute(null, "CREATE SEQUENCE IF NOT EXISTS Person;");
}

Logging

To configure client logging, add loggerFactory:

try (IgniteClient client = IgniteClient.builder()
        .addresses("127.0.0.1:10800")
        .loggerFactory(System::getLogger)
        .build()
) {
    client.sql().execute(null, "CREATE SEQUENCE IF NOT EXISTS Person;");
}

The client logs connection errors, reconnects, and retries.

Limitations

There are limitations to user types that can be used for such a mapping. Some limitations are common, and others are platform-specific due to the programming language used.

• Only flat field structure is supported, meaning no nesting user objects. This is because Ignite tables, and therefore tuples have flat structure themselves;

• Fields should be mapped to Ignite types;

• All fields in user type should either be mapped to Table column or explicitly excluded;

• All columns from Table should be mapped to some field in the user type;

• Java only: Users should implement Mapper classes for user types for more flexibility;

Client Metrics

Java

When running Java client, you need to enable metrics in the client builder:

try (IgniteClient client = IgniteClient.builder()
        .addresses("127.0.0.1:10800")
        .metricsEnabled(true)
        .build()
) {
    client.sql().execute(null, "CREATE SEQUENCE IF NOT EXISTS Person;");
}

After that, client metrics will be available to any Java monitoring tool, for example JDK Mission Control.

Available Java Metrics

Metric name	Description
ConnectionsActive	The number of currently active connections.
ConnectionsEstablished	The number of established connections.
ConnectionsLost	The number of connections lost.
ConnectionsLostTimeout	The number of connections lost due to a timeout.
HandshakesFailed	The number of failed handshakes.
HandshakesFailedTimeout	The number of handshakes that failed due to a timeout.
RequestsActive	The number of currently active requests.
RequestsSent	The number of requests sent.
RequestsCompleted	The number of completed requests. Requests are completed once a response is received.
RequestsRetried	The number of request retries.
RequestsFailed	The number of failed requests.
BytesSent	The amount of bytes sent.
BytesReceived	The amount of bytes received.
StreamerBatchesSent	The number of data streamer batches sent.
StreamerItemsSent	The number of data streamer items sent.
StreamerBatchesActive	The number of existing data streamer batches.
StreamerItemsQueued	The number of queued data streamer items.

Client Connection Configuration

There is a number of configuration properties managing the connection between the client and GridGain cluster:

try (IgniteClient client = IgniteClient.builder()
        .addresses("127.0.0.1:10800")
        .connectTimeout(5000)
        .heartbeatInterval(30000)
        .heartbeatTimeout(5000)
        .operationTimeout(3000)
        .backgroundReconnectInterval(30000)
        .retryPolicy(new RetryLimitPolicy().retryLimit(8))
        .build()
) {
    client.sql().execute(null, "CREATE SEQUENCE IF NOT EXISTS Person;");
}

Configuration name	Description
connectTimeout	Client connection timeout, in milliseconds.
heartbeatInterval	Heartbeat message interval, in milliseconds.
heartbeatTimeout	Heartbeat message timeout, in milliseconds.
operationTimeout	Operation timeout, in milliseconds.
backgroundReconnectInterval	Background reconnect interval, in milliseconds.
retryPolicy	Retry policy. By default, all read operations are retried up to 16 times, and write operations are not retried.