MySql connection exception solved

MySql connection exception solved

In the past two days, I encountered a problem connecting to mysql. I haven't completed the problem after finding someone for several days. Let's take a look at the error message first:

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Org. springframework. transaction. CannotCreateTransactionException: cocould not open Hibernate Session for transaction; nested exception is org. hibernate. exception. JDBCConnectionException: Cannot open connection

At org. springframework. orm. hibernate3.HibernateTransactionManager. doBegin (HibernateTransactionManager. java: 596)

At org. springframework. transaction. support. AbstractPlatformTransactionManager. getTransaction (AbstractPlatformTransactionManager. java: 371)

At org. springframework. transaction. interceptor. TransactionAspectSupport. createTransactionIfNecessary (TransactionAspectSupport. java: 334)

At org. springframework. transaction. interceptor. TransactionInterceptor. invoke (TransactionInterceptor. java: 105)

At org. springframework. aop. framework. ReflectiveMethodInvocation. proceed (ReflectiveMethodInvocation. java: 172)

At org. springframework. aop. framework. Cglib2AopProxy $ DynamicAdvisedInterceptor. intercept (Cglib2AopProxy. java: 622)

At hitec. dms. element. service. biz. impl. DmsMonitorThreadServiceImpl $ EnhancerByCGLIB $ a293fc8f. findList (<generated>)

At hitec. influence. platform. quartz. ThreadListener. monitorThread (ThreadListener. java: 117)

At hitec. influence. platform. quartz. job. GatherJob. process (GatherJob. java: 12)

At hitec.influence.platform.quartz.quartzdispatcher$zjob.exe cute (QuartzDispatcher. java: 377)

At org. quartz. core. JobRunShell. run (JobRunShell. java: 202)

At org. quartz. simpl. SimpleThreadPool $ WorkerThread. run (SimpleThreadPool. java: 525) Caused by: org. hibernate. exception. JDBCConnectionException: Cannot open connection

At org. hibernate. exception. SQLStateConverter. convert (SQLStateConverter. java: 97)

At org. hibernate. exception. JDBCExceptionHelper. convert (JDBCExceptionHelper. java: 66)

At org. hibernate. exception. JDBCExceptionHelper. convert (JDBCExceptionHelper. java: 52)

At org. hibernate. jdbc. ConnectionManager. openConnection (ConnectionManager. java: 449)

At org. hibernate. jdbc. ConnectionManager. getConnection (ConnectionManager. java: 167)

At org. hibernate. jdbc. JDBCContext. connection (JDBCContext. java: 142)

At org. hibernate. transaction. JDBCTransaction. begin (JDBCTransaction. java: 85)

At org. hibernate. impl. SessionImpl. beginTransaction (SessionImpl. java: 1354)

At org. springframework. orm. hibernate3.HibernateTransactionManager. doBegin (HibernateTransactionManager. java: 555)

... 11 more Caused by: com. mysql. jdbc. exceptions. jdbc4.CommunicationsException: Communications link failure

The last packet sent successfully to the server was 0 milliseconds ago. The driver has not supported Ed any packets from the server.

At sun. reflect. GeneratedConstructorAccessor248.newInstance (Unknown Source)

At sun. reflect. delegatingconstruct%cessorimpl. newInstance (delegatingconstruct%cessorimpl. java: 45)

At java. lang. reflect. Constructor. newInstance (Constructor. java: 526)

At com. mysql. jdbc. Util. handleNewInstance (Util. java: 411)

At com. mysql. jdbc. SQLError. createCommunicationsException (SQLError. java: 1117)

At com. mysql. jdbc. MysqlIO. <init> (MysqlIO. java: 350)

At com. mysql. jdbc. ConnectionImpl. coreConnect (ConnectionImpl. java: 2393)

At com. mysql. jdbc. ConnectionImpl. connectOneTryOnly (ConnectionImpl. java: 2430)

At com. mysql. jdbc. ConnectionImpl. createNewIO (ConnectionImpl. java: 2215)

At com. mysql. jdbc. ConnectionImpl. <init> (ConnectionImpl. java: 813)

At com. mysql. jdbc. JDBC4Connection. <init> (JDBC4Connection. java: 47)

At sun. reflect. GeneratedConstructorAccessor43.newInstance (Unknown Source)

At sun. reflect. delegatingconstruct%cessorimpl. newInstance (delegatingconstruct%cessorimpl. java: 45)

At java. lang. reflect. Constructor. newInstance (Constructor. java: 526)

At com. mysql. jdbc. Util. handleNewInstance (Util. java: 411)

At com. mysql. jdbc. ConnectionImpl. getInstance (ConnectionImpl. java: 399)

At com. mysql. jdbc. NonRegisteringDriver. connect (NonRegisteringDriver. java: 334)

At org. apache. commons. dbcp. DriverConnectionFactory. createConnection (DriverConnectionFactory. java: 38)

At org. apache. commons. dbcp. PoolableConnectionFactory. makeObject (PoolableConnectionFactory. java: 582)

At org. apache. commons. pool. impl. GenericObjectPool. borrowObject (GenericObjectPool. java: 1148)

At org. apache. commons. dbcp. PoolingDataSource. getConnection (PoolingDataSource. java: 106)

At org. apache. commons. dbcp. BasicDataSource. getConnection (BasicDataSource. java: 1044)

At org. springframework. orm. hibernate3.LocalDataSourceConnectionProvider. getConnection (LocalDataSourceConnectionProvider. java: 81)

At org. hibernate. jdbc. ConnectionManager. openConnection (ConnectionManager. java: 446)

... 16 more Caused by: java.net. SocketException: too many open files

At java.net. Socket. createImpl (Socket. java: 447)

At java.net. Socket. <init> (Socket. java: 421)

At java.net. Socket. <init> (Socket. java: 241)

At com. mysql. jdbc. StandardSocketFactory. connect (StandardSocketFactory. java: 257)

At com. mysql. jdbc. MysqlIO. <init> (MysqlIO. java: 300)

... 34 more

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After seeing the error message, I always thought that the connection was not closed after hibernate in the code was established, until the connection was idle for 8 hours and mysql was disconnected, later, a colleague has encountered such a problem before, but has never noticed an exception below: "more Caused by: java.net. socketException: Too Many opened files ", because my program is deployed on linux, because linux has a ulimit maximum number of opened files, the default value is 1024 (ulimit-a to view the relevant information). Later, it was found that there was an InputStream in the jar package encapsulated by others. Only the newly opened and opened files were not closed, and the open files were continuously created in a loop, when an error is reported when the value exceeds 1024 is enabled, add inputstream and disable it!