Tair (Redis® OSS-Compatible):Use direct connection mode to connect to a cluster instance

Custom connection pool (recommended)

A custom connection pool gives control over connection limits. In direct connection mode, each client connects directly to individual shards. Set pool sizes so that the total connections across all clients do not exceed the maximum connections per shard: Number of clients x MaxTotal < Maximum connections to a single shard.

import redis.clients.jedis.*;
import java.util.HashSet;
import java.util.Set;

public class DirectTest {
    private static final int DEFAULT_TIMEOUT = 2000;
    private static final int DEFAULT_REDIRECTIONS = 5;
    private static final ConnectionPoolConfig config = new ConnectionPoolConfig();

    public static void main(String args[]) {
        // Number of clients x MaxTotal < Maximum connections to a single shard.
        config.setMaxTotal(30);
        config.setMaxIdle(20);
        config.setMinIdle(15);

        // Private endpoint of the cluster instance.
        String host = "r-bp1xxxxxxxxxxxx.redis.rds.aliyuncs.com";
        int port = 6379;
        // Password for the cluster instance.
        String password = "xxxxx";

        Set<HostAndPort> jedisClusterNode = new HashSet<HostAndPort>();
        jedisClusterNode.add(new HostAndPort(host, port));
        JedisCluster jc = new JedisCluster(jedisClusterNode, DEFAULT_TIMEOUT, DEFAULT_TIMEOUT, DEFAULT_REDIRECTIONS,
            password, "clientName", config);

        jc.set("key", "value");
        jc.get("key");

        jc.close();     // Close the connection and release resources when the application exits.
    }
}

Default connection pool

import redis.clients.jedis.ConnectionPoolConfig;
import redis.clients.jedis.HostAndPort;
import redis.clients.jedis.JedisCluster;
import java.util.HashSet;
import java.util.Set;

public class DirectTest{
    private static final int DEFAULT_TIMEOUT = 2000;
    private static final int DEFAULT_REDIRECTIONS = 5;
    private static final ConnectionPoolConfig DEFAULT_CONFIG = new ConnectionPoolConfig();

    public static void main(String args[]){

        // Private endpoint of the cluster instance.
        String host = "r-bp1xxxxxxxxxxxx.redis.rds.aliyuncs.com";
        int port = 6379;
        String password = "xxxx";

        Set<HostAndPort>  jedisClusterNode = new HashSet<HostAndPort>();
        jedisClusterNode.add(new HostAndPort(host, port));

        JedisCluster jc = new JedisCluster(jedisClusterNode, DEFAULT_TIMEOUT, DEFAULT_TIMEOUT,
            DEFAULT_REDIRECTIONS,password, "clientName", DEFAULT_CONFIG);

        jc.set("key","value");
        jc.get("key");

        jc.close();     // Close the connection and release resources when the application exits.
    }
}

Step 1: Add Maven dependencies

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.4.2</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.aliyun.tair</groupId>
    <artifactId>spring-boot-example</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>spring-boot-example</name>
    <description>Demo project for Spring Boot</description>
    <properties>
        <java.version>1.8</java.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-redis</artifactId>
        </dependency>
        <dependency>
            <groupId>redis.clients</groupId>
            <artifactId>jedis</artifactId>
        </dependency>
        <dependency>
            <groupId>io.lettuce</groupId>
            <artifactId>lettuce-core</artifactId>
            <version>6.3.0.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>io.netty</groupId>
            <artifactId>netty-transport-native-epoll</artifactId>
            <version>4.1.100.Final</version>
            <classifier>linux-x86_64</classifier>
        </dependency>
    </dependencies>
    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>
</project>

Step 2: Configure the connection

Choose either Jedis (recommended) or Lettuce as the underlying client.

@Bean
    JedisConnectionFactory redisConnectionFactory() {
        List<String> clusterNodes = Arrays.asList("r-bp10noxlhcoim2****.redis.rds.aliyuncs.com:6379");
        RedisClusterConfiguration redisClusterConfiguration = new RedisClusterConfiguration(clusterNodes);
        redisClusterConfiguration.setUsername("user");
        redisClusterConfiguration.setPassword("password");


        JedisPoolConfig jedisPoolConfig = new JedisPoolConfig();
        // Number of clients x MaxTotal < Maximum connections to a single shard.
        jedisPoolConfig.setMaxTotal(30);
        jedisPoolConfig.setMaxIdle(20);
        // Disable testOn[Borrow|Return] to avoid extra ping commands.
        jedisPoolConfig.setTestOnBorrow(false);
        jedisPoolConfig.setTestOnReturn(false);

        return new JedisConnectionFactory(redisClusterConfiguration, jedisPoolConfig);
    }

/**
     * Enable TCP keepalive and configure the following three parameters:
     *  TCP_KEEPIDLE = 30
     *  TCP_KEEPINTVL = 10
     *  TCP_KEEPCNT = 3
     */
    private static final int TCP_KEEPALIVE_IDLE = 30;

    /**
     * TCP_USER_TIMEOUT avoids scenarios where Lettuce remains stuck in a
     * continuous timeout loop during a failure or crash event.
     * refer: https://github.com/lettuce-io/lettuce-core/issues/2082
     */
    private static final int TCP_USER_TIMEOUT = 30;

    @Bean
    public LettuceConnectionFactory redisConnectionFactory() {
        List<String> clusterNodes = Arrays.asList("r-bp10noxlhcoim2****.redis.rds.aliyuncs.com:6379");
        RedisClusterConfiguration redisClusterConfiguration = new RedisClusterConfiguration(clusterNodes);
        redisClusterConfiguration.setUsername("user");
        redisClusterConfiguration.setPassword("password");

        // Config TCP KeepAlive
        SocketOptions socketOptions = SocketOptions.builder()
            .keepAlive(KeepAliveOptions.builder()
                .enable()
                .idle(Duration.ofSeconds(TCP_KEEPALIVE_IDLE))
                .interval(Duration.ofSeconds(TCP_KEEPALIVE_IDLE / 3))
                .count(3)
                .build())
            .tcpUserTimeout(TcpUserTimeoutOptions.builder()
                .enable()
                .tcpUserTimeout(Duration.ofSeconds(TCP_USER_TIMEOUT))
                .build())
            .build();

        ClusterTopologyRefreshOptions topologyRefreshOptions = ClusterTopologyRefreshOptions.builder()
            .enablePeriodicRefresh(Duration.ofSeconds(60))
            .dynamicRefreshSources(false)
            .enableAllAdaptiveRefreshTriggers()
            .adaptiveRefreshTriggersTimeout(Duration.ofSeconds(15)).build();

        LettuceClientConfiguration lettuceClientConfiguration = LettuceClientConfiguration.builder().
            clientOptions(ClusterClientOptions.builder()
                .socketOptions(socketOptions)
                .validateClusterNodeMembership(false)
                .topologyRefreshOptions(topologyRefreshOptions).build()).build();

        return new LettuceConnectionFactory(redisClusterConfiguration, lettuceClientConfiguration);
    }

Step 1: Add Maven dependencies

<dependency>
            <groupId>io.lettuce</groupId>
            <artifactId>lettuce-core</artifactId>
            <version>6.3.0.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>io.netty</groupId>
            <artifactId>netty-transport-native-epoll</artifactId>
            <version>4.1.65.Final</version>
            <classifier>linux-x86_64</classifier>
        </dependency>

Step 2: Add the connection code

Replace the values of host, port, and password with the actual instance information.

import io.lettuce.core.RedisURI;
import io.lettuce.core.SocketOptions;
import io.lettuce.core.cluster.ClusterClientOptions;
import io.lettuce.core.cluster.ClusterTopologyRefreshOptions;
import io.lettuce.core.cluster.RedisClusterClient;
import io.lettuce.core.cluster.api.StatefulRedisClusterConnection;

import java.time.Duration;

public class ClusterDemo {
    /**
     * Enable TCP keepalive and configure the following three parameters:
     *  TCP_KEEPIDLE = 30
     *  TCP_KEEPINTVL = 10
     *  TCP_KEEPCNT = 3
     */
    private static final int TCP_KEEPALIVE_IDLE = 30;

    /**
     * TCP_USER_TIMEOUT avoids situations where Lettuce remains stuck in a
     * continuous timeout loop during a failure or crash event.
     * refer: https://github.com/lettuce-io/lettuce-core/issues/2082
     */
    private static final int TCP_USER_TIMEOUT = 30;

    public static void main(String[] args) throws Exception {
        // Replace with the actual instance information.
        String host = "r-bp1ln3c4kopj3l****.redis.rds.aliyuncs.com";
        int port = 6379;
        String password = "Da****3";

        RedisURI redisURI = RedisURI.Builder.redis(host)
                .withPort(port)
                .withPassword(password)
                .build();

        ClusterTopologyRefreshOptions refreshOptions = ClusterTopologyRefreshOptions.builder()
                .enablePeriodicRefresh(Duration.ofSeconds(60))
                .dynamicRefreshSources(false)
                .enableAllAdaptiveRefreshTriggers()
                .adaptiveRefreshTriggersTimeout(Duration.ofSeconds(15)).build();

        // Config TCP KeepAlive
        SocketOptions socketOptions = SocketOptions.builder()
                .keepAlive(SocketOptions.KeepAliveOptions.builder()
                        .enable()
                        .idle(Duration.ofSeconds(TCP_KEEPALIVE_IDLE))
                        .interval(Duration.ofSeconds(TCP_KEEPALIVE_IDLE/3))
                        .count(3)
                        .build())
                .tcpUserTimeout(SocketOptions.TcpUserTimeoutOptions.builder()
                        .enable()
                        .tcpUserTimeout(Duration.ofSeconds(TCP_USER_TIMEOUT))
                        .build())
                .build();

        RedisClusterClient redisClient = RedisClusterClient.create(redisURI);
        redisClient.setOptions(ClusterClientOptions.builder()
                .socketOptions(socketOptions)
                .validateClusterNodeMembership(false)
                .topologyRefreshOptions(refreshOptions).build());

        StatefulRedisClusterConnection<String, String> connection = redisClient.connect();
        connection.sync().set("key", "value");
        System.out.println(connection.sync().get("key"));
    }
}

Expected output on success:

value

Why does the MOVED 4578 172.18.xx.xxx:6379 error occur?

The MOVED <slot> <IP:Port> error means the requested key is on a different node. This typically happens when the client does not support the Redis Cluster protocol. Common scenarios include:

• Connecting with redis-cli without the -c option.

• Using the standard redis-py client in Python, which does not handle automatic redirection. Use the redis.cluster.RedisCluster class instead.

For information about other errors, see Common errors and troubleshooting.