昨天遇到一个问题，开发说一个jar包启动后，几分钟就出现oracle数据库用户连接超时；但是该服务器上的其他war或jar都是正常连接数据库！！！
详细错误
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:47)
at org.hibernate.engine.jdbc.internal.StatementPreparerImpl$5.doPrepare(StatementPreparerImpl.java:146)
at org.hibernate.engine.jdbc.internal.StatementPreparerImpl$StatementPreparationTemplate.prepareStatement(StatementPreparerImpl.java:172)
at org.hibernate.engine.jdbc.internal.StatementPreparerImpl.prepareQueryStatement(StatementPreparerImpl.java:148)
at org.hibernate.loader.Loader.prepareQueryStatement(Loader.java:1984)
at org.hibernate.loader.Loader.executeQueryStatement(Loader.java:1914)
at org.hibernate.loader.Loader.executeQueryStatement(Loader.java:1892)
at org.hibernate.loader.Loader.doQuery(Loader.java:937)
at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:340)
at org.hibernate.loader.Loader.doList(Loader.java:2689)
at org.hibernate.loader.Loader.doList(Loader.java:2672)
at org.hibernate.loader.Loader.listIgnoreQueryCache(Loader.java:2506)
at org.hibernate.loader.Loader.list(Loader.java:2501)
at org.hibernate.loader.custom.CustomLoader.list(CustomLoader.java:338)
at org.hibernate.internal.SessionImpl.listCustomQuery(SessionImpl.java:2223)
at org.hibernate.internal.AbstractSharedSessionContract.list(AbstractSharedSessionContract.java:1053)
at org.hibernate.query.internal.NativeQueryImpl.doList(NativeQueryImpl.java:170)
at org.hibernate.query.internal.AbstractProducedQuery.list(AbstractProducedQuery.java:1505)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.springframework.orm.jpa.SharedEntityManagerCreator$DeferredQueryInvocationHandler.invoke(SharedEntityManagerCreator.java:402)
at com.sun.proxy.$Proxy117.list(Unknown Source)
at com.ceiec.report.task.dao.impl.ReportDutyDaoImpl.getEffectiveDutyList(ReportDutyDaoImpl.java:103)
at com.ceiec.report.task.dao.impl.ReportDutyDaoImpl$$FastClassBySpringCGLIB$$b0b803b.invoke(<generated>)
at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:218)
at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.invokeJoinpoint(CglibAopProxy.java:749)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:163)
at org.springframework.dao.support.PersistenceExceptionTranslationInterceptor.invoke(PersistenceExceptionTranslationInterceptor.java:139)
... 18 common frames omitted
Caused by: java.sql.SQLTransientConnectionException: HikariPool-1 - Connection is not available, request timed out after 30003ms.
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)
at org.hibernate.engine.jdbc.connections.internal.DatasourceConnectionProviderImpl.getConnection(DatasourceConnectionProviderImpl.java:122)
at org.hibernate.internal.NonContextualJdbcConnectionAccess.obtainConnection(NonContextualJdbcConnectionAccess.java:35)
at org.hibernate.resource.jdbc.internal.LogicalConnectionManagedImpl.acquireConnectionIfNeeded(LogicalConnectionManagedImpl.java:106)
... 49 common frames omitted
检查顺序：
1 检查oracle 用户连接，登录并查看process参数，数据库等信息-----------发现用户正常连接-----排除用户，数据库等异常
2 该服务器上有启动3个war程序，多个jar包，只有这一个jar包出现了oracle用户连接问题，--------怀疑是jar包问题，将jar包拷贝到其他服务器，或本地windows，运行，还是3分钟后就出现 用户连接超时---排除服务器异常
3 检查sql语句-------------由于该jar包里面是一个10秒钟的定时程序，执行一条sql，把sql放在sqlplus中执行，结果返回2行，时间很快（100ms）----排除sql问题
4 查看服务器内存
[root@localhost upload]# free -m
total used free shared buffers cached
Mem: 15953 15670 282 0 263 2138
-/+ buffers/cache: 13267 2685
Swap: 5983 201 5782
以为是内存用完，将该服务器上所有java程序重启（该服务有多个服务器进行负载均衡，可以重启任意一个服务器的java服务）
再次查看内存
[root@localhost report]# free -m
total used free shared buffers cached
Mem: 15953 10754 5199 0 262 2394
-/+ buffers/cache: 8097 7855
Swap: 5983 67 5916
在内存正常情况下， 该jar包服务还是启动后3分钟就报错~！！！！！---------排除内存异常
5 top查看服务器，cpu，load，mem等都是正常。-------
top - 09:46:22 up 38 days, 16:05, 2 users, load average: 0.00, 0.00, 0.00
Tasks: 284 total, 2 running, 282 sleeping, 0 stopped, 0 zombie
Cpu(s): 1.2%us, 0.5%sy, 0.0%ni, 98.3%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st
Mem: 16335960k total, 12137624k used, 4198336k free, 278312k buffers
Swap: 6127608k total, 69288k used, 6058320k free, 2648196k cached
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
3974 root 20 0 9390m 2.2g 20m S 3.6 14.1 44:05.30 java
35 root 20 0 0 0 0 S 0.3 0.0 2:56.82 events/0
39 root 20 0 0 0 0 S 0.3 0.0 2:12.62 events/4
2594 rabbitmq 20 0 5331m 50m 3528 S 0.3 0.3 284:39.65 beam.smp
2807 rabbitmq 20 0 10800 436 404 S 0.3 0.0 0:04.58 inet_gethost
3453 root 20 0 7748m 1.1g 13m S 0.3 6.9 5:08.01 java
3594 root 20 0 7774m 1.0g 13m S 0.3 6.6 2:59.17 java
3674 root 20 0 5278m 672m 13m S 0.3 4.2 2:33.51 java
3812 root 20 0 6129m 613m 13m S 0.3 3.8 3:31.06 java
3878 root 20 0 4693m 528m 12m S 0.3 3.3 3:16.51 java
4665 root 20 0 4623m 439m 13m S 0.3 2.8 3:09.45 java
15295 root 20 0 15172 1392 948 R 0.3 0.0 0:00.02 top
1 root 20 0 19356 1300 1088 S 0.0 0.0 0:40.50 init
6 无赖之，进行谷歌，百度~~~
有提到什么springboot配置，
spring.datasource.hikari.read-only=false spring.datasource.hikari.connection-timeout=60000 spring.datasource.hikari.idle-timeout=60000 spring.datasource.hikari.validation-timeout=3000 spring.datasource.hikari.max-lifetime=60000 spring.datasource.hikari.login-timeout=5 spring.datasource.hikari.maximum-pool-size=60 spring.datasource.hikari.minimum-idle=10
看不懂~~~发给开发同学。。。等了一段时间。答复到，加了一个事务，自动提交。。。程序就正常了。~~~~~~~！！！！！！！
由于只执行了一条sql查询语句，不存在需要提交的情况，应该是框架的问题
总结：不懂开发，这种问题还是不好排查啊！！！！----什么狗屁总结