我的服务器上有一个spring启动项目。我有时会遇到“hikari池连接不可用”错误。我想不出原因。我看起来有很多这样的问题。一些人建议关闭一些@交易。但是，在我的应用程序中，我没有使用任何@transactional注解。以下是我的hikari池配置：

# hikari settings

spring.datasource.hikari.connectionTimeout=30000
spring.datasource.hikari.idleTimeout=600000
spring.datasource.hikari.maxLifetime=1800000
spring.datasource.hikari.maximumPoolSize=10

# hikari log

logging.level.com.zaxxer.hikari.HikariConfig=DEBUG
logging.level.com.zaxxer.hikari=TRACE

当我检查catalina.out日志文件时，我注意到活动连接数有时会增加。例如，昨天没有活动的连接。所有连接都处于空闲状态。现在池中有2个活动连接。我得到这个错误是因为连接池被所有活动的连接填充了吗？
顺便说一下，我使用的是mysql数据库。我应该设置maxlifetime比mysql wait\u timeout少一秒或两秒吗？我问这个问题是因为https://github.com/brettwooldridge/hikaricp，maxlifetime应该比任何数据库或基础结构强加的连接时间限制短几秒。你认为maxlifetime和等待超时有关吗？
以下是错误跟踪：

Caused by: org.hibernate.exception.JDBCConnectionException: Unable to acquire JDBC Connection
        at org.hibernate.exception.internal.SQLExceptionTypeDelegate.convert(SQLExceptionTypeDelegate.java:48)
        at org.hibernate.exception.internal.StandardSQLExceptionConverter.convert(StandardSQLExceptionConverter.java:42)
        at org.hibernate.engine.jdbc.spi.SqlExceptionHelper.convert(SqlExceptionHelper.java:113)
        at org.hibernate.engine.jdbc.spi.SqlExceptionHelper.convert(SqlExceptionHelper.java:99)
        at org.hibernate.resource.jdbc.internal.LogicalConnectionManagedImpl.acquireConnectionIfNeeded(LogicalConnectionManagedImpl.java:109)
        at org.hibernate.resource.jdbc.internal.LogicalConnectionManagedImpl.getPhysicalConnection(LogicalConnectionManagedImpl.java:136)
        at org.hibernate.engine.jdbc.internal.StatementPreparerImpl.connection(StatementPreparerImpl.java:50)
        at org.hibernate.engine.jdbc.internal.StatementPreparerImpl$5.doPrepare(StatementPreparerImpl.java:149)
        at org.hibernate.engine.jdbc.internal.StatementPreparerImpl$StatementPreparationTemplate.prepareStatement(StatementPreparerImpl.java:176)
        at org.hibernate.engine.jdbc.internal.StatementPreparerImpl.prepareQueryStatement(StatementPreparerImpl.java:151)
        at org.hibernate.loader.Loader.prepareQueryStatement(Loader.java:2082)
        at org.hibernate.loader.Loader.executeQueryStatement(Loader.java:2012)
        at org.hibernate.loader.Loader.executeQueryStatement(Loader.java:1990)
        at org.hibernate.loader.Loader.doQuery(Loader.java:949)
        at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:351)
        at org.hibernate.loader.Loader.doList(Loader.java:2787)
        at org.hibernate.loader.Loader.doList(Loader.java:2770)
        at org.hibernate.loader.Loader.listIgnoreQueryCache(Loader.java:2604)
        at org.hibernate.loader.Loader.list(Loader.java:2599)
        at org.hibernate.loader.custom.CustomLoader.list(CustomLoader.java:338)
        at org.hibernate.internal.SessionImpl.listCustomQuery(SessionImpl.java:2254)
        at org.hibernate.internal.AbstractSharedSessionContract.list(AbstractSharedSessionContract.java:1069)
        at org.hibernate.query.internal.NativeQueryImpl.doList(NativeQueryImpl.java:170)
        at org.hibernate.query.internal.AbstractProducedQuery.list(AbstractProducedQuery.java:1506)
        ... 116 more
Caused by: java.sql.SQLTransientConnectionException: HikariPool-1 - Connection is not available, request timed out after 30001ms.
        at com.zaxxer.hikari.pool.HikariPool.createTimeoutException(HikariPool.java:676)
        at com.zaxxer.hikari.pool.HikariPool.getConnection(HikariPool.java:190)
        at com.zaxxer.hikari.pool.HikariPool.getConnection(HikariPool.java:155)
        at com.zaxxer.hikari.HikariDataSource.getConnection(HikariDataSource.java:128)