Почему происходит утечка соединений в HikariPool?

Question

EgorSvinarev @EgorSvinarev

Java
Spring

Почему происходит утечка соединений в HikariPool?

Здравствуйте. Имеются следующие

Зависимости

<dependencies>
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-data-jpa</artifactId>
			<version>2.5.5</version>
		</dependency>

		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-web</artifactId>
		</dependency>
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-devtools</artifactId>
			<scope>runtime</scope>
			<optional>true</optional>
		</dependency>
		<dependency>
			<groupId>org.postgresql</groupId>
			<artifactId>postgresql</artifactId>
			<version>42.3.0</version>
			<scope>runtime</scope>
		</dependency>
		<dependency>
			<groupId>org.projectlombok</groupId>
			<artifactId>lombok</artifactId>
			<optional>true</optional>
		</dependency>
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-test</artifactId>
			<scope>test</scope>
		</dependency>
		<dependency>
			<groupId>io.swagger.core.v3</groupId>
			<artifactId>swagger-annotations</artifactId>
			<version>2.1.10</version>
		</dependency>
		<dependency>
			<groupId>org.springdoc</groupId>
			<artifactId>springdoc-openapi-ui</artifactId>
			<version>1.5.11</version>
		</dependency>
		<dependency>
		    <groupId>javax.validation</groupId>
		    <artifactId>validation-api</artifactId>
		    <version>2.0.1.Final</version>
		</dependency>
		<dependency>
			<groupId>org.apache.commons</groupId>
			<artifactId>commons-io</artifactId>
			<version>1.3.2</version>
		</dependency>
		<dependency>
		    <groupId>com.fasterxml.jackson.core</groupId>
		    <artifactId>jackson-databind</artifactId>
		    <version>2.13.3</version>
		</dependency>
	</dependencies>

Конфигурация подключения к бд

spring.datasource.hikari.connection-timeout = 60000
spring.datasource.hikari.minimum-idle = 10
spring.datasource.hikari.maximum-pool-size = 30
spring.datasource.hikari.idle-timeout = 10000
spring.datasource.hikari.max-lifetime = 1000
spring.datasource.hikari.auto-commit = true

Код репозитория

@Repository
public interface ExerciseRepository extends JpaRepository <Exercise, Long> {
	
	@Transactional
	Optional<Exercise> findById(Long id);
	
}

При большой нагрузке начинает вылетать

exception

2022-11-14 17:57:29.390 DEBUG 1 --- [http-nio-8080-exec-110] com.zaxxer.hikari.pool.HikariPool : HikariPool-1 - Timeout failure stats (total=30, active=30, idle=0, waiting=55)
2022-11-14 17:57:29.390 WARN 1 --- [http-nio-8080-exec-110] o.h.engine.jdbc.spi.SqlExceptionHelper : SQL Error: 0, SQLState: null
2022-11-14 17:57:29.390 ERROR 1 --- [http-nio-8080-exec-110] o.h.engine.jdbc.spi.SqlExceptionHelper : HikariPool-1 - Connection is not available, request timed out after 60000ms.
2022-11-14 17:57:29.392 ERROR 1 --- [http-nio-8080-exec-110] o.a.c.c.C.[.[.[/].[dispatcherServlet] : Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed; nested exception is org.springframework.transaction.CannotCreateTransactionException: Could not open JPA EntityManager for transaction; nested exception is org.hibernate.exception.JDBCConnectionException: Unable to acquire JDBC Connection] with root cause

java.sql.SQLTransientConnectionException: HikariPool-1 - Connection is not available, request timed out after 60000ms.
at com.zaxxer.hikari.pool.HikariPool.createTimeoutException(HikariPool.java:696) ~[HikariCP-4.0.3.jar!/:na]
at com.zaxxer.hikari.pool.HikariPool.getConnection(HikariPool.java:197) ~[HikariCP-4.0.3.jar!/:na]
at com.zaxxer.hikari.pool.HikariPool.getConnection(HikariPool.java:162) ~[HikariCP-4.0.3.jar!/:na]
at com.zaxxer.hikari.HikariDataSource.getConnection(HikariDataSource.java:128) ~[HikariCP-4.0.3.jar!/:na]
at org.hibernate.engine.jdbc.connections.internal.DatasourceConnectionProviderImpl.getConnection(DatasourceConnectionProviderImpl.java:122) ~[hibernate-core-5.6.8.Final.jar!/:5.6.8.Final]
at org.hibernate.internal.NonContextualJdbcConnectionAccess.obtainConnection(NonContextualJdbcConnectionAccess.java:38) ~[hibernate-core-5.6.8.Final.jar!/:5.6.8.Final]
at org.hibernate.resource.jdbc.internal.LogicalConnectionManagedImpl.acquireConnectionIfNeeded(LogicalConnectionManagedImpl.java:108) ~[hibernate-core-5.6.8.Final.jar!/:5.6.8.Final]
at org.hibernate.resource.jdbc.internal.LogicalConnectionManagedImpl.getPhysicalConnection(LogicalConnectionManagedImpl.java:138) ~[hibernate-core-5.6.8.Final.jar!/:5.6.8.Final]
at org.hibernate.resource.jdbc.internal.LogicalConnectionManagedImpl.getConnectionForTransactionManagement(LogicalConnectionManagedImpl.java:276) ~[hibernate-core-5.6.8.Final.jar!/:5.6.8.Final]
at org.hibernate.resource.jdbc.internal.LogicalConnectionManagedImpl.begin(LogicalConnectionManagedImpl.java:284)

В каком месте происходит утечка?