go.adoc

Go Client

Overview

This section provides information about the Go client for Hazelcast, and explains how to install and get started with the client.

Tip	To learn how to get started quickly with the Hazelcast Go client, follow our simple Get started with Go tutorial.

The official Hazelcast Go client allows Go applications to connect to and interact with Hazelcast clusters. The key features and benefits include:

• Distributed data structures: supports Hazelcast distributed data structures like Map, Queue, Set, List, MultiMap, and Replicated Map.

• SQL support: allows running SQL queries on Hazelcast 5.x clusters using our proprietary API or via the database/sql compatible driver. See: Driver documentation.

• High performance: offers high-performance aggregation functions such as sum, average, max, and min, for Hazelcast Map entries. See: Aggregation functions.

• Near cache: client-side cache that improves read performance for frequently accessed data. See: Using the Near Cache.

• External client public address discovery: enables using public addresses instead of private ones in Kubernetes clusters. See: External Client Public Address Discovery.

The Hazelcast Go client provides a robust, efficient, and Go-friendly way to work with Hazelcast clusters, enabling you to build scalable and distributed applications with ease.

Tip	For the latest Go API documentation, see Hazelcast Go Client documentation.

Install the Go client

This section explains how to install the Hazelcast Go client.

Requirements:

• The Hazelcast Go client is compatible with Hazelcast 4.x, and upwards.

• Hazelcast supports the two most recent versions of the Go programming language at the time each new Go client is released.

In your Go module-enabled project, add a dependency to github.com/hazelcast/hazelcast-go-client:

go get github.com/hazelcast/hazelcast-go-client@latest

Quick start

The Hazelcast Go client requires a working Hazelcast cluster to run. The cluster handles storage and manipulation of the user data. Clients are a way to connect to the Hazelcast cluster and access the data.

To start a free trial of Hazelcast {enterprise-product-name}, see Get started.

Start the default client

Start the client with the default Hazelcast host and port using hazelcast.StartNewClient, when Hazelcast is running locally with the default options:

ctx := context.TODO()
client, err := hazelcast.StartNewClient(ctx)

Tip	For more information, see: Unboxing Hazelcast Go Client.

Start the client with given options

If you want to change the default configuration, you can specify options at runtime.

Note that Config structs are not thread-safe. Complete creation of the configuration in a single goroutine.

In the following example, you create the default configuration, optionally set member addresses manually, create and start the client with the given configuration, and handle a client start error:

config := hazelcast.Config{}
config.Cluster.Network.SetAddresses("member1.example.com:5701", "member2.example.com:5701")
client, err := hazelcast.StartNewClientWithConfig(ctx, config)

Sample code

The following example creates a Go client instance, connects to a cluster, gets and populates a map and prints the data.

package main

import (
	"context"
	"fmt"
	"log"

	"github.com/hazelcast/hazelcast-go-client"
)

func main() {
	ctx := context.TODO()
	// create the client and connect to the cluster on localhost
	client, err := hazelcast.StartNewClient(ctx)
	if err != nil {
		log.Fatal(err)
	}
	// get a map
	people, err := client.GetMap(ctx, "people")
	if err != nil {
		log.Fatal(err)
	}
	personName := "Jane Doe"
	// set a value in the map
	if err = people.Set(ctx, personName, 30); err != nil {
		log.Fatal(err)
	}
	// get a value from the map
	age, err := people.Get(ctx, personName)
	if err != nil {
		log.Fatal(err)
	}
	fmt.Printf("%s is %d years old.\n", personName, age)
	// stop the client to release resources
	client.Shutdown(ctx)
}

Get support

Join us in the Go Client channel.

Next steps

Hazelcast Go Client documentation is hosted at pkg.go.dev.

Use godoc to view the documentation locally:

godoc -http=localhost:5500

Note that godoc is not installed by default with the base Go distribution. You can install it using:

go get -u golang.org/x/tools/...`

See also the Hazelcast Go client GitHub repo and code samples.