Connecting to Redis on Jedis (Java)

Prerequisites

• A Redis instance is created, and is in the Running state. To create a Redis instance, see Buying a DCS Redis Instance.
• View the IP address/domain name and port number of the DCS Redis instance to be accessed. For details, see Viewing and Modifying Basic Settings of a DCS Instance.
• The client and the Redis instance must be interconnected before connecting to the instance. For details, see Network Conditions for Accessing DCS Redis.

Pom Configuration

<!-- import spring-data-redis -->
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-data-redis</artifactId>
<!--In Spring Boot 2.0, Lettuce is used by default. To use Jedis, solve dependency conflicts.-->
    <exclusions>
        <exclusion>
            <groupId>io.lettuce</groupId>
            <artifactId>lettuce-core</artifactId>
        </exclusion>
    </exclusions>
</dependency>
<!--Jedis dependency>
<dependency>
    <groupId>redis.clients</groupId>
    <artifactId>jedis</artifactId>
    <version>${jedis.version}<version>
</dependency>

application.properties Configuration

• Single-node, master/standby, read/write splitting, and Proxy Cluster

  #Redis host
  spring.redis.host=<host>
  #Redis port
  spring.redis.port=<port>
  #Redis database number
  spring.redis.database=0
  #Redis password
  spring.redis.password=<password>
  #Redis read/write timeout
  spring.redis.timeout=2000
  #Whether to enable connection pooling
  spring.redis.jedis.pool.enabled=true
  #Minimum connections in the pool
  spring.redis.jedis.pool.min-idle=50
  #Maximum idle connections in the pool
  spring.redis.jedis.pool.max-idle=200
  #Maximum connections in the pool
  spring.redis.jedis.pool.max-active=200
  #Maximum amount of time a connection allocation should block before throwing an exception when the pool is exhausted. The default value -1 indicates to wait indefinitely.
  spring.redis.jedis.pool.max-wait=3000
  #Interval for checking and evicting idle connection. Default: 60s.
  spring.redis.jedis.pool.time-between-eviction-runs=60S

• Redis Cluster

  #Redis Cluster node connection information
  spring.redis.cluster.nodes=<ip:port>,<ip:port>,<ip:port>
  #Redis Cluster password
  spring.redis.password=<password>
  #Redis Cluster max. redirecting times
  spring.redis.cluster.max-redirects=3
  #Redis read/write timeout
  spring.redis.timeout=2000
  #Whether to enable connection pooling
  spring.redis.jedis.pool.enabled=true
  #Minimum connections in the pool
  spring.redis.jedis.pool.min-idle=50
  #Maximum idle connections in the pool
  spring.redis.jedis.pool.max-idle=200
  #Maximum connections in the pool
  spring.redis.jedis.pool.max-active=200
  #Maximum amount of time a connection allocation should block before throwing an exception when the pool is exhausted. The default value -1 indicates to wait indefinitely.
  spring.redis.jedis.pool.max-wait=3000
  #Interval for checking and evicting idle connections. Default: 60s.
  spring.redis.jedis.pool.time-between-eviction-runs=60S

Bean Configuration

• Single-node, master/standby, read/write splitting, and Proxy Cluster

  import java.time.Duration;
  
  import org.springframework.beans.factory.annotation.Value;
  import org.springframework.context.annotation.Bean;
  import org.springframework.context.annotation.Configuration;
  import org.springframework.data.redis.connection.RedisConnectionFactory;
  import org.springframework.data.redis.connection.RedisStandaloneConfiguration;
  import org.springframework.data.redis.connection.jedis.JedisClientConfiguration;
  import org.springframework.data.redis.connection.jedis.JedisConnectionFactory;
  
  import redis.clients.jedis.JedisPoolConfig;
  
  @Configuration
  public class RedisConfiguration {
  
      @Value("${redis.host}")
      private String redisHost;
  
      @Value("${redis.port:6379}")
      private Integer redisPort = 6379;
  
      @Value("${redis.database:0}")
      private Integer redisDatabase = 0;
  
      @Value("${redis.password:}")
      private String redisPassword;
  
      @Value("${redis.connect.timeout:3000}")
      private Integer redisConnectTimeout = 3000;
  
      @Value("${redis.read.timeout:2000}")
      private Integer redisReadTimeout = 2000;
  
      @Value("${redis.pool.minSize:50}")
      private Integer redisPoolMinSize = 50;
  
      @Value("${redis.pool.maxSize:200}")
      private Integer redisPoolMaxSize = 200;
  
      @Value("${redis.pool.maxWaitMillis:3000}")
      private Integer redisPoolMaxWaitMillis = 3000;
  
      @Value("${redis.pool.softMinEvictableIdleTimeMillis:1800000}")
      private Integer redisPoolSoftMinEvictableIdleTimeMillis = 30 * 60 * 1000;
  
      @Value("${redis.pool.timeBetweenEvictionRunsMillis:60000}")
      private Integer redisPoolBetweenEvictionRunsMillis = 60 * 1000;
  
      @Bean
      public RedisConnectionFactory redisConnectionFactory(JedisClientConfiguration clientConfiguration) {
  
          RedisStandaloneConfiguration standaloneConfiguration = new RedisStandaloneConfiguration();
          standaloneConfiguration.setHostName(redisHost);
          standaloneConfiguration.setPort(redisPort);
          standaloneConfiguration.setDatabase(redisDatabase);
          standaloneConfiguration.setPassword(redisPassword);
  
          return new JedisConnectionFactory(standaloneConfiguration, clientConfiguration);
      }
  
      @Bean
      public JedisClientConfiguration clientConfiguration() {
  
          JedisClientConfiguration clientConfiguration = JedisClientConfiguration.builder()
                  .connectTimeout(Duration.ofMillis(redisConnectTimeout))
                  .readTimeout(Duration.ofMillis(redisReadTimeout))
                  .usePooling().poolConfig(redisPoolConfig())
                  .build();
  
          return clientConfiguration;
      }
  
      private JedisPoolConfig redisPoolConfig() {
  
          JedisPoolConfig poolConfig = new JedisPoolConfig();
          //Minimum connections in the pool
          poolConfig.setMinIdle(redisPoolMinSize);
          //Maximum idle connections in the pool
          poolConfig.setMaxIdle(redisPoolMaxSize);
          //Maximum total connections in the pool
          poolConfig.setMaxTotal(redisPoolMaxSize);
          //Wait when pool is exhausted? Set to true to wait. To validate setMaxWait, it has to be true.
          poolConfig.setBlockWhenExhausted(true);
          //Longest time to wait for connection after pool is exhausted. The default value -1 indicates to wait indefinitely.
          poolConfig.setMaxWaitMillis(redisPoolMaxWaitMillis);
          //Set to true to enable connectivity test on creating connections. Default: false.
          poolConfig.setTestOnCreate(false);
          //Set to true to enable connectivity test on borrowing connections. Default: false. Set to false for heavy-traffic services to reduce overhead.
          poolConfig.setTestOnBorrow(true);
          //Set to true to enable connectivity test on returning connections. Default: false. Set to false for heavy-traffic services to reduce overhead.
          poolConfig.setTestOnReturn(false);
          //Indicates whether to check for idle connections. If this is set to false, idle connections are not evicted.
          poolConfig.setTestWhileIdle(true);
          //Duration after which idle connections are evicted. If the idle duration is greater than this value and the maximum number of idle connections is reached, idle connections are directly evicted.
          poolConfig.setSoftMinEvictableIdleTimeMillis(redisPoolSoftMinEvictableIdleTimeMillis);
          //Disable MinEvictableIdleTimeMillis().
          poolConfig.setMinEvictableIdleTimeMillis(-1);
          //Interval for checking and evicting idle connections. Default: 60s.
          poolConfig.setTimeBetweenEvictionRunsMillis(redisPoolBetweenEvictionRunsMillis);
          return poolConfig;
      }
  }

• Redis Cluster

  import java.time.Duration;
  import java.util.ArrayList;
  import java.util.List;
  
  import org.springframework.beans.factory.annotation.Value;
  import org.springframework.context.annotation.Bean;
  import org.springframework.context.annotation.Configuration;
  import org.springframework.data.redis.connection.RedisClusterConfiguration;
  import org.springframework.data.redis.connection.RedisConnectionFactory;
  import org.springframework.data.redis.connection.RedisNode;
  import org.springframework.data.redis.connection.jedis.JedisClientConfiguration;
  import org.springframework.data.redis.connection.jedis.JedisConnectionFactory;
  
  import redis.clients.jedis.JedisPoolConfig;
  
  @Configuration
  public class RedisConfiguration {
  
      @Value("${redis.cluster.nodes}")
      private String redisClusterNodes;
  
      @Value("${redis.password:}")
      private String redisPassword;
  
      @Value("${redis.connect.timeout:3000}")
      private Integer redisConnectTimeout = 3000;
  
      @Value("${redis.read.timeout:2000}")
      private Integer redisReadTimeout = 2000;
  
      @Value("${redis.pool.minSize:50}")
      private Integer redisPoolMinSize = 50;
  
      @Value("${redis.pool.maxSize:200}")
      private Integer redisPoolMaxSize = 200;
  
      @Value("${redis.pool.maxWaitMillis:3000}")
      private Integer redisPoolMaxWaitMillis = 3000;
  
      @Value("${redis.pool.softMinEvictableIdleTimeMillis:1800000}")
      private Integer redisPoolSoftMinEvictableIdleTimeMillis = 30 * 60 * 1000;
  
      @Value("${redis.pool.timeBetweenEvictionRunsMillis:60000}")
      private Integer redisPoolBetweenEvictionRunsMillis = 60 * 1000;
  
      @Bean
      public RedisConnectionFactory redisConnectionFactory(JedisClientConfiguration clientConfiguration) {
  
          RedisClusterConfiguration clusterConfiguration = new RedisClusterConfiguration();
  
          List<RedisNode> clusterNodes = new ArrayList<>();
          for (String clusterNodeStr : redisClusterNodes.split(",")) {
              String[] nodeInfo = clusterNodeStr.split(":");
              clusterNodes.add(new RedisNode(nodeInfo[0], Integer.valueOf(nodeInfo[1])));
          }
          clusterConfiguration.setClusterNodes(clusterNodes);
  
          clusterConfiguration.setPassword(redisPassword);
          clusterConfiguration.setMaxRedirects(3);
  
          return new JedisConnectionFactory(clusterConfiguration, clientConfiguration);
      }
  
      @Bean
      public JedisClientConfiguration clientConfiguration() {
  
          JedisClientConfiguration clientConfiguration = JedisClientConfiguration.builder()
                  .connectTimeout(Duration.ofMillis(redisConnectTimeout))
                  .readTimeout(Duration.ofMillis(redisReadTimeout))
                  .usePooling().poolConfig(redisPoolConfig())
                  .build();
  
          return clientConfiguration;
      }
  
      private JedisPoolConfig redisPoolConfig() {
  
          JedisPoolConfig poolConfig = new JedisPoolConfig();
          //Minimum connections in the pool
          poolConfig.setMinIdle(redisPoolMinSize);
          //Maximum idle connections in the pool
          poolConfig.setMaxIdle(redisPoolMaxSize);
          //Maximum total connections in the pool
          poolConfig.setMaxTotal(redisPoolMaxSize);
          //Wait when pool is exhausted? Set to true to wait. To validate setMaxWait, it has to be true.
          poolConfig.setBlockWhenExhausted(true);
          //Longest time to wait for connection after pool is exhausted. The default value -1 indicates to wait indefinitely.
          poolConfig.setMaxWaitMillis(redisPoolMaxWaitMillis);
          //Set to true to enable connectivity test on creating connections. Default: false.
          poolConfig.setTestOnCreate(false);
          //Set to true to enable connectivity test on borrowing connections. Default: false. Set to false for heavy-traffic services to reduce overhead.
          poolConfig.setTestOnBorrow(true);
          //Set to true to enable connectivity test on returning connections. Default: false. Set to false for heavy-traffic services to reduce overhead.
          poolConfig.setTestOnReturn(false);
          //Indicates whether to check for idle connections. If this is set to false, idle connections are not evicted.
          poolConfig.setTestWhileIdle(true);
          //Duration after which idle connections are evicted. If the idle duration is greater than this value and the maximum number of idle connections is reached, idle connections are directly evicted.
          poolConfig.setSoftMinEvictableIdleTimeMillis(redisPoolSoftMinEvictableIdleTimeMillis);
          //Disable MinEvictableIdleTimeMillis().
          poolConfig.setMinEvictableIdleTimeMillis(-1);
          //Interval for checking and evicting idle connections. Default: 60s.
          poolConfig.setTimeBetweenEvictionRunsMillis(redisPoolBetweenEvictionRunsMillis);
          return poolConfig;
      }
  }

(Optional) Configuring SSL Connections

If SSL is enabled for the instance, use the following content to replace the JedisClientConfiguration construction method clientConfiguration() in Bean Configuration for connecting to the instance with SSL. For details about whether your DCS Redis instances support SSL, see Transmitting DCS Redis Data with Encryption Using SSL.

@Bean
public JedisClientConfiguration clientConfiguration() throws Exception {
    JedisClientConfiguration.JedisClientConfigurationBuilder configurationBuilder
        = JedisClientConfiguration.builder()
        .connectTimeout(Duration.ofMillis(redisConnectTimeout))
        .readTimeout(Duration.ofMillis(redisReadTimeout));

    configurationBuilder.usePooling().poolConfig(redisPoolConfig());
    configurationBuilder.useSsl().sslSocketFactory(getTrustStoreSslSocketFactory());
    return configurationBuilder.build();
}

private SSLSocketFactory getTrustStoreSslSocketFactory() throws Exception{
    //Load the CA certificate in the user-defined path based on service requirements.
    CertificateFactory cf = CertificateFactory.getInstance("X.509");
    Certificate ca;
    try (InputStream is = new FileInputStream("./ca.crt")) {
        ca = cf.generateCertificate(is);
    }

    //Create keystore.
    String keyStoreType = KeyStore.getDefaultType();
    KeyStore keyStore = KeyStore.getInstance(keyStoreType);
    keyStore.load(null, null);
    keyStore.setCertificateEntry("ca", ca);

    //Create TrustManager.
    TrustManagerFactory trustManagerFactory = TrustManagerFactory.getInstance(
        TrustManagerFactory.getDefaultAlgorithm());
    trustManagerFactory.init(keyStore);

    //Create SSLContext.
    SSLContext context = SSLContext.getInstance("TLS");
    context.init(null, trustManagerFactory.getTrustManagers(), new SecureRandom());
    return context.getSocketFactory();
}

Parameter Description

Suggestion for Configuring DCS Instances

• Connection pool configuration
  

  The following calculation is applicable only to common service scenarios. You can customize it based on your service requirements.

  There is no standard connection pool size. You can configure one based on your service traffic. The following formulas are for reference:

  • Minimum number of connections = (QPS of a single node accessing Redis)/(1000 ms/Average time spent on a single command)
  • Maximum number of connections = (QPS of a single node accessing Redis)/(1000 ms/Average time spent on a single command) x 150%

  For example, if the QPS of a service application is about 10,000, each request needs to access Redis 10 times (that is, 100,000 accesses to Redis every second), and the service application has 10 hosts, the calculation is as follows:

  QPS of a single node accessing Redis = 100,000/10 = 10,000

  Average time spent on a single command = 20 ms (Redis takes 5 ms to 10 ms to process a single command under normal conditions. If network jitter occurs, it takes 15 ms to 20 ms.)

  Minimum number of connections = 10,000/(1000 ms/20 ms) = 200

  Maximum number of connections = 10,000/(1000 ms/20 ms) x 150% = 300