MyBatis closed db connection

[aitor]

Hello!!!

Every morning I see a DB connection error trace in my logs before doing any operation.
After doing some operation the error disappears (MyBatis reestablishes the connection).
Everything works fine, but there are many traces of error in my logs.

How I can avoid this?

This is my ProcessEngine configuration:

String jdbcUrl = "jdbc:oracle:thin:@192.168.2.1:1521:MYDATABASE";
String jdbcDriver = "oracle.jdbc.OracleDriver";
String jdbcUsr = "myuser";
String jdbcPwd = "mypwd";

ProcessEngineConfiguration processEngineConfig = ProcessEngineConfiguration
   .createStandaloneProcessEngineConfiguration()
   .setJdbcUrl(jdbcUrl)
   .setJdbcDriver(jdbcDriver)
   .setJdbcUsername(jdbcUsr)
   .setJdbcPassword(jdbcPwd)
   .setJobExecutorActivate(true)
   .setHistory(HistoryLevel.FULL.getKey());
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And this is the exception I see every morning:

04:52:00,608 ERROR [org.activiti.engine.impl.jobexecutor.AcquireJobsRunnable] (Thread-73) exception during job acquisition: 
### Error querying database.  Cause: java.sql.SQLException: Excepción de E/S: The Network Adapter could not establish the connection
### The error may exist in org/activiti/db/mapping/entity/Job.xml
### The error may involve org.activiti.engine.impl.persistence.entity.JobEntity.selectNextJobsToExecute
### The error occurred while executing a query
### Cause: java.sql.SQLException: Excepción de E/S: The Network Adapter could not establish the connection
04:53:01,619 ERROR [org.activiti.engine.impl.interceptor.CommandContext] (Thread-73) Error while closing command context: org.apache.ibatis.exceptions.PersistenceException: 
### Error querying database.  Cause: java.sql.SQLException: Excepción de E/S: The Network Adapter could not establish the connection
### The error may exist in org/activiti/db/mapping/entity/Job.xml
### The error may involve org.activiti.engine.impl.persistence.entity.JobEntity.selectNextJobsToExecute
### The error occurred while executing a query
### Cause: java.sql.SQLException: Excepción de E/S: The Network Adapter could not establish the connection
   at org.apache.ibatis.exceptions.ExceptionFactory.wrapException(ExceptionFactory.java:23) [mybatis-3.2.2.jar:3.2.2]
   at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:107) [mybatis-3.2.2.jar:3.2.2]
   at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:98) [mybatis-3.2.2.jar:3.2.2]
   at org.activiti.engine.impl.db.DbSqlSession.selectListWithRawParameter(DbSqlSession.java:286) [activiti-engine-5.14.jar:5.14]
   at org.activiti.engine.impl.db.DbSqlSession.selectList(DbSqlSession.java:277) [activiti-engine-5.14.jar:5.14]
   at org.activiti.engine.impl.db.DbSqlSession.selectList(DbSqlSession.java:272) [activiti-engine-5.14.jar:5.14]
   at org.activiti.engine.impl.db.DbSqlSession.selectList(DbSqlSession.java:259) [activiti-engine-5.14.jar:5.14]
   at org.activiti.engine.impl.persistence.entity.JobEntityManager.findNextJobsToExecute(JobEntityManager.java:105) [activiti-engine-5.14.jar:5.14]
   at org.activiti.engine.impl.cmd.AcquireJobsCmd.execute(AcquireJobsCmd.java:48) [activiti-engine-5.14.jar:5.14]
   at org.activiti.engine.impl.cmd.AcquireJobsCmd.execute(AcquireJobsCmd.java:33) [activiti-engine-5.14.jar:5.14]
   at org.activiti.engine.impl.interceptor.CommandInvoker.execute(CommandInvoker.java:24) [activiti-engine-5.14.jar:5.14]
   at org.activiti.engine.impl.interceptor.CommandContextInterceptor.execute(CommandContextInterceptor.java:57) [activiti-engine-5.14.jar:5.14]
   at org.activiti.engine.impl.interceptor.LogInterceptor.execute(LogInterceptor.java:31) [activiti-engine-5.14.jar:5.14]
   at org.activiti.engine.impl.cfg.CommandExecutorImpl.execute(CommandExecutorImpl.java:40) [activiti-engine-5.14.jar:5.14]
   at org.activiti.engine.impl.cfg.CommandExecutorImpl.execute(CommandExecutorImpl.java:35) [activiti-engine-5.14.jar:5.14]
   at org.activiti.engine.impl.jobexecutor.AcquireJobsRunnable.run(AcquireJobsRunnable.java:59) [activiti-engine-5.14.jar:5.14]
   at java.lang.Thread.run(Thread.java:722) [rt.jar:1.7.0_17]
Caused by: java.sql.SQLException: Excepción de E/S: The Network Adapter could not establish the connection
   at oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java:112) [ojdbc14.jar:Oracle JDBC Driver version - "10.2.0.2.0"]
   at oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java:146) [ojdbc14.jar:Oracle JDBC Driver version - "10.2.0.2.0"]
   at oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java:255) [ojdbc14.jar:Oracle JDBC Driver version - "10.2.0.2.0"]
   at oracle.jdbc.driver.T4CConnection.logon(T4CConnection.java:387) [ojdbc14.jar:Oracle JDBC Driver version - "10.2.0.2.0"]
   at oracle.jdbc.driver.PhysicalConnection.<init>(PhysicalConnection.java:420) [ojdbc14.jar:Oracle JDBC Driver version - "10.2.0.2.0"]
   at oracle.jdbc.driver.T4CConnection.<init>(T4CConnection.java:165) [ojdbc14.jar:Oracle JDBC Driver version - "10.2.0.2.0"]
   at oracle.jdbc.driver.T4CDriverExtension.getConnection(T4CDriverExtension.java:35) [ojdbc14.jar:Oracle JDBC Driver version - "10.2.0.2.0"]
   at oracle.jdbc.driver.OracleDriver.connect(OracleDriver.java:801) [ojdbc14.jar:Oracle JDBC Driver version - "10.2.0.2.0"]
   at java.sql.DriverManager.getConnection(DriverManager.java:579) [rt.jar:1.7.0_17]
   at java.sql.DriverManager.getConnection(DriverManager.java:190) [rt.jar:1.7.0_17]
   at org.apache.ibatis.datasource.unpooled.UnpooledDataSource.doGetConnection(UnpooledDataSource.java:180) [mybatis-3.2.2.jar:3.2.2]
   at org.apache.ibatis.datasource.unpooled.UnpooledDataSource.doGetConnection(UnpooledDataSource.java:175) [mybatis-3.2.2.jar:3.2.2]
   at org.apache.ibatis.datasource.unpooled.UnpooledDataSource.getConnection(UnpooledDataSource.java:79) [mybatis-3.2.2.jar:3.2.2]
   at org.apache.ibatis.datasource.pooled.PooledDataSource.popConnection(PooledDataSource.java:373) [mybatis-3.2.2.jar:3.2.2]
   at org.apache.ibatis.datasource.pooled.PooledDataSource.getConnection(PooledDataSource.java:82) [mybatis-3.2.2.jar:3.2.2]
   at org.apache.ibatis.transaction.jdbc.JdbcTransaction.openConnection(JdbcTransaction.java:131) [mybatis-3.2.2.jar:3.2.2]
   at org.apache.ibatis.transaction.jdbc.JdbcTransaction.getConnection(JdbcTransaction.java:58) [mybatis-3.2.2.jar:3.2.2]
   at org.apache.ibatis.executor.BaseExecutor.getConnection(BaseExecutor.java:271) [mybatis-3.2.2.jar:3.2.2]
   at org.apache.ibatis.executor.SimpleExecutor.prepareStatement(SimpleExecutor.java:69) [mybatis-3.2.2.jar:3.2.2]
   at org.apache.ibatis.executor.SimpleExecutor.doQuery(SimpleExecutor.java:56) [mybatis-3.2.2.jar:3.2.2]
   at org.apache.ibatis.executor.BaseExecutor.queryFromDatabase(BaseExecutor.java:259) [mybatis-3.2.2.jar:3.2.2]
   at org.apache.ibatis.executor.BaseExecutor.query(BaseExecutor.java:132) [mybatis-3.2.2.jar:3.2.2]
   at org.apache.ibatis.executor.CachingExecutor.query(CachingExecutor.java:105) [mybatis-3.2.2.jar:3.2.2]
   at org.apache.ibatis.executor.CachingExecutor.query(CachingExecutor.java:81) [mybatis-3.2.2.jar:3.2.2]
   at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:104) [mybatis-3.2.2.jar:3.2.2]
   … 15 more
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Thanks for the help,
Aitor.

[jbarrez]

Seems like you would need a keepalive/ping on the connections.

Following settings are available on the ProcessEngineConfiguration:

protected int jdbcMaxActiveConnections;
  protected int jdbcMaxIdleConnections;
  protected int jdbcMaxCheckoutTime;
  protected int jdbcMaxWaitTime;
  protected boolean jdbcPingEnabled = false;
  protected String jdbcPingQuery = null;
  protected int jdbcPingConnectionNotUsedFor;
  protected int jdbcDefaultTransactionIsolationLevel;