title: DB connection is getting lost after some time in spring boot
body: <p>We are facing this problem when the application starts DB connection gets created and after some time connection gets closed by the server. We are using Postgres in Amazon RDS.</p>
  
  <pre><code>2019-12-13 14:02:33.385  WARN 1 --- [io-8080-exec-41] o.h.engine.jdbc.spi.SqlExceptionHelper   : SQL Error: 0, SQLState: null
  2019-12-13 14:02:33.386 ERROR 1 --- [io-8080-exec-41] o.h.engine.jdbc.spi.SqlExceptionHelper   : HikariPool-1 - Connection is not available, request timed out after 30000ms.
  2019-12-13 14:02:33.391 ERROR 1 --- [io-8080-exec-41] 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.dao.DataAccessResourceFailureException: Unable to acquire JDBC Connection; 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 30000ms.
      at com.zaxxer.hikari.pool.HikariPool.createTimeoutException(HikariPool.java:669) ~[HikariCP-2.7.9.jar!/:na]
      at com.zaxxer.hikari.pool.HikariPool.getConnection(HikariPool.java:183) ~[HikariCP-2.7.9.jar!/:na]
      at com.zaxxer.hikari.pool.HikariPool.getConnection(HikariPool.java:148) ~[HikariCP-2.7.9.jar!/:na]
      at com.zaxxer.hikari.HikariDataSource.getConnection(HikariDataSource.java:128) ~[HikariCP-2.7.9.jar!/:na]
      at org.hibernate.engine.jdbc.connections.internal.DatasourceConnectionProviderImpl.getConnection(DatasourceConnectionProviderImpl.java:122) ~[hibernate-core-5.2.17.Final.jar!/:5.2.17.Final]
      at org.hibernate.internal.NonContextualJdbcConnectionAccess.obtainConnection(NonContextualJdbcConnectionAccess.java:35) ~[hibernate-core-5.2.17.Final.jar!/:5.2.17.Final]
      at org.hibernate.resource.jdbc.internal.LogicalConnectionManagedImpl.acquireConnectionIfNeeded(LogicalConnectionManagedImpl.java:106) ~[hibernate-core-5.2.17.Final.jar!/:5.2.17.Final]
      at org.hibernate.resource.jdbc.internal.LogicalConnectionManagedImpl.getPhysicalConnection(LogicalConnectionManagedImpl.java:136) ~[hibernate-core-5.2.17.Final.jar!/:5.2.17.Final]
      at org.hibernate.engine.jdbc.internal.StatementPreparerImpl.connection(StatementPreparerImpl.java:47) ~[hibernate-core-5.2.17.Final.jar!/:5.2.17.Final]
      at org.hibernate.engine.jdbc.internal.StatementPreparerImpl$5.doPrepare(StatementPreparerImpl.java:145) ~[hibernate-core-5.2.17.Final.jar!/:5.2.17.Final]
      at org.hibernate.engine.jdbc.internal.StatementPreparerImpl$StatementPreparationTemplate.prepareStatement(StatementPreparerImpl.java:171) ~[hibernate-core-5.2.17.Final.jar!/:5.2.17.Final]
      at org.hibernate.engine.jdbc.internal.StatementPreparerImpl.prepareQueryStatement(StatementPreparerImpl.java:147) ~[hibernate-core-5.2.17.Final.jar!/:5.2.17.Final]
      at org.hibernate.loader.Loader.prepareQueryStatement(Loader.java:1985) ~[hibernate-core-5.2.17.Final.jar!/:5.2.17.Final]
      at org.hibernate.loader.Loader.executeQueryStatement(Loader.java:1915) ~[hibernate-core-5.2.17.Final.jar!/:5.2.17.Final]
      at org.hibernate.loader.Loader.executeQueryStatement(Loader.java:1893) ~[hibernate-core-5.2.17.Final.jar!/:5.2.17.Final]
      at org.hibernate.loader.Loader.doQuery(Loader.java:938) ~[hibernate-core-5.2.17.Final.jar!/:5.2.17.Final]
      at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:341) ~[hibernate-core-5.2.17.Final.jar!/:5.2.17.Final]
      at org.hibernate.loader.Loader.doList(Loader.java:2692) ~[hibernate-core-5.2.17.Final.jar!/:5.2.17.Final]
      at org.hibernate.loader.Loader.doList(Loader.java:2675) ~[hibernate-core-5.2.17.Final.jar!/:5.2.17.Final]
      at org.hibernate.loader.Loader.listIgnoreQueryCache(Loader.java:2507) ~[hibernate-core-5.2.17.Final.jar!/:5.2.17.Final]
      at org.hibernate.loader.Loader.list(Loader.java:2502) ~[hibernate-core-5.2.17.Final.jar!/:5.2.17.Final]
      at org.hibernate.loader.hql.QueryLoader.list(QueryLoader.java:502) ~[hibernate-core-5.2.17.Final.jar!/:5.2.17.Final]
      at org.hibernate.hql.internal.ast.QueryTranslatorImpl.list(QueryTranslatorImpl.java:392) ~[hibernate-core-5.2.17.Final.jar!/:5.2.17.Final]
      at org.hibernate.engine.query.spi.HQLQueryPlan.performList(HQLQueryPlan.java:216) ~[hibernate-core-5.2.17.Final.jar!/:5.2.17.Final]
      at org.hibernate.internal.SessionImpl.list(SessionImpl.java:1490) ~[hibernate-core-5.2.17.Final.jar!/:5.2.17.Final]
      at org.hibernate.query.internal.AbstractProducedQuery.doList(AbstractProducedQuery.java:1445) ~[hibernate-core-5.2.17.Final.jar!/:5.2.17.Final]
      at org.hibernate.query.internal.AbstractProducedQuery.list(AbstractProducedQuery.java:1414) ~[hibernate-core-5.2.17.Final.jar!/:5.2.17.Final]
      at org.hibernate.query.internal.AbstractProducedQuery.getSingleResult(AbstractProducedQuery.java:1463) ~[hibernate-core-5.2.17.Final.jar!/:5.2.17.Final]
      at org.hibernate.query.criteria.internal.compile.CriteriaQueryTypeQueryAdapter.getSingleResult(CriteriaQueryTypeQueryAdapter.java:107) ~[hibernate-core-5.2.17.Final.jar!/:5.2.17.Final]
      at org.springframework.data.jpa.repository.query.JpaQueryExecution$SingleEntityExecution.doExecute(JpaQueryExecution.java:214) ~[spring-data-jpa-2.0.10.RELEASE.jar!/:2.0.10.RELEASE]
      at org.springframework.data.jpa.repository.query.JpaQueryExecution.execute(JpaQueryExecution.java:91) ~[spring-data-jpa-2.0.10.RELEASE.jar!/:2.0.10.RELEASE]
      at org.springframework.data.jpa.repository.query.AbstractJpaQuery.doExecute(AbstractJpaQuery.java:136) ~[spring-data-jpa-2.0.10.RELEASE.jar!/:2.0.10.RELEASE]
      at org.springframework.data.jpa.repository.query.AbstractJpaQuery.execute(AbstractJpaQuery.java:125) ~[spring-data-jpa-2.0.10.RELEASE.jar!/:2.0.10.RELEASE]
      at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.doInvoke(RepositoryFactorySupport.java:602) ~[spring-data-commons-2.0.10.RELEASE.jar!/:2.0.10.RELEASE]
      at 
  
  </code></pre>