0.12.0版本，java原生接口使用完的连接似乎没有归还连接池

^{Originally posted by **lordtang** December 1, 2021}
**版本信息：**
服务器版本：0.12.0
maven iotdb-session依赖版本：0.12.0

步骤：
1.导入maven依赖：
```

org.apache.iotdb
iotdb-session
0.12.0

```

2.配置Session-pool
```
@Configuration
public class IotDbConfig {
@Bean
public SessionPool sessionPool() {
//连接池最大数量
int maxsize = 20;
return new SessionPool(
"127.0.0.1",
6667,
"root",
"root",
maxsize);
}
}
```

3.单线程执行20次该方法
```
public SessionDataSetWrapper executeSql(String sql) throws IoTDBConnectionException, StatementExecutionException {
return sessionPool.executeQueryStatement(sql);
}
```

现象：
```
15:35:15.194 [http-nio-8080-exec-1] WARN o.a.i.s.p.SessionPool - [getSession,244] - the SessionPool has wait for 60 seconds to get a new connection: 127.0.0.1:6667 with root, root
15:35:15.194 [http-nio-8080-exec-1] WARN o.a.i.s.p.SessionPool - [getSession,251] - current occupied size 20, queue size 0, considered size 20
org.apache.iotdb.rpc.IoTDBConnectionException: timeout to get a connection from 127.0.0.1:6667
at org.apache.iotdb.session.pool.SessionPool.getSession(SessionPool.java:258)
at org.apache.iotdb.session.pool.SessionPool.executeQueryStatement(SessionPool.java:1099)
at com.ruoyi.common.utils.IotDBUtils.getTimeseries(IotDBUtils.java:35)
at com.ruoyi.system.service.impl.IotDBServiceImpl.getDeviceData(IotDBServiceImpl.java:49)
at com.ruoyi.web.controller.device.DeviceController.deviceData(DeviceController.java:67)
at com.ruoyi.web.controller.device.DeviceController$$FastClassBySpringCGLIB$$43987eb1.invoke()
at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:218)
at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.invokeJoinpoint(CglibAopProxy.java:783)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:163)
at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.proceed(CglibAopProxy.java:753)
at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:97)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186)
at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.proceed(CglibAopProxy.java:753)
at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:698)
at com.ruoyi.web.controller.device.DeviceController$$EnhancerBySpringCGLIB$$25da8380.deviceData()
at sun.reflect.GeneratedMethodAccessor298.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:205)
at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:150)
at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:117)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:895)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:808)
at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87)
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1067)
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:963)
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1006)
at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:909)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:681)
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:883)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:764)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:227)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:113)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:113)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162)
at com.alibaba.druid.support.http.WebStatFilter.doFilter(WebStatFilter.java:124)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162)
at com.ruoyi.common.filter.RepeatableFilter.doFilter(RepeatableFilter.java:43)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:327)
at org.springframework.security.web.access.intercept.FilterSecurityInterceptor.invoke(FilterSecurityInterceptor.java:115)
at org.springframework.security.web.access.intercept.FilterSecurityInterceptor.doFilter(FilterSecurityInterceptor.java:81)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:336)
at org.springframework.security.web.access.ExceptionTranslationFilter.doFilter(ExceptionTranslationFilter.java:121)
at org.springframework.security.web.access.ExceptionTranslationFilter.doFilter(ExceptionTranslationFilter.java:115)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:336)
at org.springframework.security.web.session.SessionManagementFilter.doFilter(SessionManagementFilter.java:126)
at org.springframework.security.web.session.SessionManagementFilter.doFilter(SessionManagementFilter.java:81)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:336)
at org.springframework.security.web.authentication.AnonymousAuthenticationFilter.doFilter(AnonymousAuthenticationFilter.java:105)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:336)
at org.springframework.security.web.servletapi.SecurityContextHolderAwareRequestFilter.doFilter(SecurityContextHolderAwareRequestFilter.java:149)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:336)
at org.springframework.security.web.savedrequest.RequestCacheAwareFilter.doFilter(RequestCacheAwareFilter.java:63)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:336)
at com.ruoyi.framework.security.filter.JwtAuthenticationTokenFilter.doFilterInternal(JwtAuthenticationTokenFilter.java:42)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:336)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:113)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:336)
at org.springframework.security.web.authentication.logout.LogoutFilter.doFilter(LogoutFilter.java:103)
at org.springframework.security.web.authentication.logout.LogoutFilter.doFilter(LogoutFilter.java:89)
AbstractProtocol.java:895)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1722)
at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
at org.apache.tomcat.util.threads.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1191)
at org.apache.tomcat.util.threads.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:659)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Thread.java:748)
```

最新的版本似乎可以使用
https://github.com/apache/iotdb/blob/master/example/session/src/main/java/org/apache/iotdb/SessionPoolExample.java
中的
pool.closeResultSet(wrapper);关闭连接。可是0.12.0调用该API似乎并不起作用