![SQL Error: 0, SQLState: 08S01 Communications link failure [duplicate]](https://liberty.io/uploads/sql-error-0-sqlstate-08s01-communications-link-failure-duplicate_720.jpg)
I am getting this error (not so frequently):
2013-05-08 16:44:35,786 WARN (JDBCExceptionReporter.java:100) [org.hibernate.util.JDBCExceptionReporter, logExceptions] - SQL Error: 0, SQLState: 08S01 2013-05-08 16:44:35,786 ERROR (JDBCExceptionReporter.java:101) [org.hibernate.util.JDBCExceptionReporter, logExceptions] - Communications link failure The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server. 2013-05-08 16:44:35,833 ERROR (AdminDaoImpl.java:297) [com.myapp.admin.db.AdminDaoImpl, createFilePackage] - data-upload: Exception while adding new file package org.hibernate.exception.JDBCConnectionException: Cannot open connection at org.hibernate.exception.SQLStateConverter.convert(SQLStateConverter.java:97) [hibernate-core-3.3.2.GA.jar:3.3.2.GA] at org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:66) [hibernate-core-3.3.2.GA.jar:3.3.2.GA] at org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:52) [hibernate-core-3.3.2.GA.jar:3.3.2.GA] at org.hibernate.jdbc.ConnectionManager.openConnection(ConnectionManager.java:449) [hibernate-core-3.3.2.GA.jar:3.3.2.GA] at org.hibernate.jdbc.ConnectionManager.getConnection(ConnectionManager.java:167) [hibernate-core-3.3.2.GA.jar:3.3.2.GA] at org.hibernate.jdbc.JDBCContext.connection(JDBCContext.java:142) [hibernate-core-3.3.2.GA.jar:3.3.2.GA] at org.hibernate.transaction.JDBCTransaction.begin(JDBCTransaction.java:85) [hibernate-core-3.3.2.GA.jar:3.3.2.GA] at org.hibernate.impl.SessionImpl.beginTransaction(SessionImpl.java:1354) [hibernate-core-3.3.2.GA.jar:3.3.2.GA] at com.myapp.admin.db.AdminDaoImpl. createFilePackage(AdminDaoImpl.java:182) [AdminDaoImpl.class:na] at com.myapp.admin.ctrl.UploadController.processUploadZip(UploadController.java:217) [UploadController.class:na] at sun.reflect.GeneratedMethodAccessor106.invoke(Unknown Source) [na:na] at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) [na:1.6.0_35] at java.lang.reflect.Method.invoke(Method.java:597) [na:1.6.0_35] at org.springframework.web.method.support.InvocableHandlerMethod.invoke(InvocableHandlerMethod.java:212) [spring-web-3.1.0.RELEASE.jar:3.1.0.RELEASE] at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:126) [spring-web-3.1.0.RELEASE.jar:3.1.0.RELEASE] at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:96) [spring-webmvc-3.1.0.RELEASE.jar:3.1.0.RELEASE] at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:617) [spring-webmvc-3.1.0.RELEASE.jar:3.1.0.RELEASE] at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:578) [spring-webmvc-3.1.0.RELEASE.jar:3.1.0.RELEASE] at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:80) [spring-webmvc-3.1.0.RELEASE.jar:3.1.0.RELEASE] at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:900) [spring-webmvc-3.1.0.RELEASE.jar:3.1.0.RELEASE] at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:827) [spring-webmvc-3.1.0.RELEASE.jar:3.1.0.RELEASE] at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:882) [spring-webmvc-3.1.0.RELEASE.jar:3.1.0.RELEASE] at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:789) [spring-webmvc-3.1.0.RELEASE.jar:3.1.0.RELEASE] at javax.servlet.http.HttpServlet.service(HttpServlet.java:647) [servlet-api.jar:na] at javax.servlet.http.HttpServlet.service(HttpServlet.java:728) [servlet-api.jar:na] at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305) [catalina.jar:7.0.35] at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210) [catalina.jar:7.0.35] at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:222) [catalina.jar:7.0.35] at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:123) [catalina.jar:7.0.35] at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472) [catalina.jar:7.0.35] at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:171) [catalina.jar:7.0.35] at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:99) [catalina.jar:7.0.35] at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118) [catalina.jar:7.0.35] at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:407) [catalina.jar:7.0.35] at org.apache.coyote.ajp.AjpProcessor.process(AjpProcessor.java:200) [tomcat-coyote.jar:7.0.35] at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:589) [tomcat-coyote.jar:7.0.35] at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:310) [tomcat-coyote.jar:7.0.35] at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886) [na:1.6.0_35] at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908) [na:1.6.0_35] at java.lang.Thread.run(Thread.java:662) [na:1.6.0_35] Caused by: com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure I have two web (spring mvc + hibernate + mysql) applications hosted on shared server:
1) main app to show files for download (which is inserted through admin app)
2) admin app with CRUD operations
This error appears sometime, when I am using "admin" application to upload files for "main" app, lets say may be after successfully uploading/processing around 100-120 files/requests and on each request hitting database with 10-20 insert/update queries.
Hosting Details:
Private tomcat hosting java 1.6.0_35-b10 tomcat 7.0.35 heap size 288MB MySQL Server 5 commons-dbcp 1.2.2 mysql-connector-java 5.1.9 Database + Hibernate + DBCP properties:
<bean> <property name="driverClassName" value="com.mysql.jdbc.Driver" /> <property name="username" value="test" /> <property name="password" value="test" /> <property name="url" value="jdbc:mysql://localhost/my_database?useUnicode=yes&characterEncoding=UTF-8" /> <!-- DBCP Connection Pool Settings --> <property name="defaultAutoCommit" value="true" /> <property name="initialSize" value="10" /> <property name="maxActive" value="500" /> <property name="maxIdle" value="8" /> <property name="minIdle" value="0" /> <property name="maxWait" value="30000" /> <property name="validationQuery" value="SELECT 1" /> <property name="testOnBorrow" value="true" /> <property name="testOnReturn" value="false" /> <property name="testWhileIdle" value="false" /> <property name="timeBetweenEvictionRunsMillis" value="-1" /> <property name="numTestsPerEvictionRun" value="3" /> <property name="minEvictableIdleTimeMillis" value="180000" /> <property name="poolPreparedStatements" value="true" /> <property name="maxOpenPreparedStatements" value="25" /> <property name="accessToUnderlyingConnectionAllowed" value="false" /> <property name="removeAbandoned" value="false" /> <property name="removeAbandonedTimeout" value="300" /> <property name="logAbandoned" value="false" /> </bean> hibernate.dialect=org.hibernate.dialect.MySQLDialect hibernate.hbm2ddl.auto=none hibernate.jdbc.batch_size=100 hibernate.show_sql=false hibernate.format_sql=false hibernate.cache.use_second_level_cache=true hibernate.cache.use_query_cache=false hibernate.cache.provider_class=org.hibernate.cache.NoCacheProvider hibernate.current_session_context_class=thread Concerned Code:
public String createFilePackage(FilePackage package) { String message = ""; Session session = getSessionFactory().openSession(); Transaction tx = null; try { tx = session.beginTransaction(); // handling package, around 10-14 DB insert, 10 SELECT and 5 update queries on same session tx.commit(); } catch(Exception e) { logger.error("file-upload: Exception while adding new font package", e); if(tx != null) { tx.rollback(); } } finally { session.close(); } return message; } any advise how to solve this issue?
24 Answers
The communication link between the driver and the data source to which the driver was attempting to connect failed before the function completed processing. So usually its a network error. This could be caused by packet drops or badly configured Firewall/Switch.
2Check your server config file /etc/mysql/my.cnf - verify bind_address is not set to 127.0.0.1. Set it to 0.0.0.0 or comment it out then restart server with:
sudo service mysql restart I'm answering on specific to this error code(08s01).
usually, MySql close socket connections are some interval of time that is wait_timeout defined on MySQL server-side which by default is 8hours. so if a connection will timeout after this time and the socket will throw an exception which SQLState is "08s01".
1.use connection pool to execute Query, make sure the pool class has a function to make an inspection of the connection members before it goes time_out.
2.give a value of <wait_timeout> greater than the default, but the largest value is 24 days
3.use another parameter in your connection URL, but this method is not recommended, and maybe deprecated.
1Could be due to the TCP protocol turned off.
