Lettuce min-idle config does not work

Author: geminiKim

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/data/redis/LettuceConnectionConfiguration.java

@@ -146,6 +146,8 @@ private GenericObjectPoolConfig<?> getPoolConfig(Pool properties) {
 			config.setMaxTotal(properties.getMaxActive());
 			config.setMaxIdle(properties.getMaxIdle());
 			config.setMinIdle(properties.getMinIdle());
+			config.setTimeBetweenEvictionRunsMillis(
+					properties.getIdleEvictPeriod().toMillis());
 			if (properties.getMaxWait() != null) {
 				config.setMaxWaitMillis(properties.getMaxWait().toMillis());
 			}

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/data/redis/RedisProperties.java

@@ -172,6 +172,9 @@ public static class Pool {
 		/**
 		 * Target for the minimum number of idle connections to maintain in the pool. This
 		 * setting only has an effect if it is positive.
+		 *
+		 * This setting only has an effect if it is positive and `idleEvictPeriod` is
+		 * greater than zero.
 		 */
 		private int minIdle = 0;
 
@@ -188,6 +191,14 @@ public static class Pool {
 		 */
 		private Duration maxWait = Duration.ofMillis(-1);
 
+		/**
+		 * Time of milliseconds to sleep between runs of the idle object evictor thread.
+		 *
+		 * When positive, the idle object evictor thread starts. When non-positive, no
+		 * idle object evictor thread runs.
+		 */
+		private Duration idleEvictPeriod = Duration.ofMillis(-1);
+
 		public int getMaxIdle() {
 			return this.maxIdle;
 		}
@@ -220,6 +231,14 @@ public void setMaxWait(Duration maxWait) {
 			this.maxWait = maxWait;
 		}
 
+		public Duration getIdleEvictPeriod() {
+			return this.idleEvictPeriod;
+		}
+
+		public void setIdleEvictPeriod(Duration idleEvictPeriod) {
+			this.idleEvictPeriod = idleEvictPeriod;
+		}
+
 	}
 
 	/**

spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/data/redis/RedisAutoConfigurationTests.java

@@ -155,6 +155,7 @@ public void testRedisConfigurationWithPool() {
 				"spring.redis.lettuce.pool.max-idle:4",
 				"spring.redis.lettuce.pool.max-active:16",
 				"spring.redis.lettuce.pool.max-wait:2000",
+				"spring.redis.lettuce.pool.idle-evict-period:30000",
 				"spring.redis.lettuce.shutdown-timeout:1000").run((context) -> {
 					LettuceConnectionFactory cf = context
 							.getBean(LettuceConnectionFactory.class);
@@ -165,6 +166,8 @@ public void testRedisConfigurationWithPool() {
 					assertThat(poolConfig.getMaxIdle()).isEqualTo(4);
 					assertThat(poolConfig.getMaxTotal()).isEqualTo(16);
 					assertThat(poolConfig.getMaxWaitMillis()).isEqualTo(2000);
+					assertThat(poolConfig.getTimeBetweenEvictionRunsMillis())
+							.isEqualTo(30000);
 					assertThat(cf.getShutdownTimeout()).isEqualTo(1000);
 				});
 	}