java 47 lines · 7 steps

Backing HTTP sessions with Redis in Spring

A Spring config class that stores servlet sessions in Redis, tuning the connection, serialization, and cookie behavior.

Explained by highlit
Spring Intermediate session-management redis distributed-state configuration cookies
1@Configuration
2@EnableRedisHttpSession(namespace = "myapp:sessions", maxInactiveIntervalInSeconds = 1800, flushMode = FlushMode.IMMEDIATE)
3public class SessionConfig {
4 
5 @Bean
6 public LettuceConnectionFactory redisConnectionFactory(
7 @Value("${spring.redis.host}") String host,
8 @Value("${spring.redis.port}") int port,
9 @Value("${spring.redis.password:}") String password) {
10 
11 RedisStandaloneConfiguration standalone = new RedisStandaloneConfiguration(host, port);
12 if (!password.isBlank()) {
13 standalone.setPassword(RedisPassword.of(password));
14 }
15 
16 LettuceClientConfiguration clientConfig = LettuceClientConfiguration.builder()
17 .commandTimeout(Duration.ofSeconds(2))
18 .clientOptions(ClientOptions.builder()
19 .autoReconnect(true)
20 .disconnectedBehavior(ClientOptions.DisconnectedBehavior.REJECT_COMMANDS)
21 .build())
22 .build();
23 
24 return new LettuceConnectionFactory(standalone, clientConfig);
25 }
26 
27 @Bean
28 public RedisSerializer<Object> springSessionDefaultRedisSerializer() {
29 return new GenericJackson2JsonRedisSerializer();
30 }
31 
32 @Bean
33 public CookieSerializer cookieSerializer() {
34 DefaultCookieSerializer serializer = new DefaultCookieSerializer();
35 serializer.setCookieName("MYAPPSESSION");
36 serializer.setCookiePath("/");
37 serializer.setUseHttpOnlyCookie(true);
38 serializer.setSameSite("Lax");
39 serializer.setUseSecureCookie(true);
40 return serializer;
41 }
42 
43 @Bean
44 public ConfigureRedisAction configureRedisAction() {
45 return ConfigureRedisAction.NO_OP;
46 }
47}
01 / 01
STEP 01

Walkthrough

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Three takeaways
  1. 1Externalizing HTTP sessions to Redis lets multiple app instances share login state without sticky sessions.
  2. 2Explicit serializer and cookie beans give you control over on-disk format and browser security attributes.
  3. 3Connection options like command timeouts and disconnected behavior decide how the app fails when Redis is unreachable.

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