数据库连接mysql, 一直正常的, 今天突然就报错,测试连接失败. 无从下手,请问是什么原因?

com.fr.third.alibaba.druid.pool.GetConnectionTimeoutException: wait millis 10000, active 0, maxActive 50, creating 1, createElapseMillis 343716

com.fr.third.alibaba.druid.pool.DruidDataSource.getConnectionInternal(DruidDataSource.java.1839)

com.fr.third.alibaba.druid.pool.DruidDataSource.getConnectionDirect(DruidDataSource.java.1483)

com.fr.third.alibaba.druid.pool.DruidDataSource.getConnection(DruidDataSource.java.1463)

com.fr.third.alibaba.druid.pool.DruidDataSource.getConnection(DruidDataSource.java.1452)

com.fr.third.alibaba.druid.pool.DruidDataSource.getConnection(DruidDataSource.java.100)

com.fr.stable.pool.DataSourceAdapter.getConnection(DataSourceAdapter.java.60)

com.fr.stable.pool.DataSourceAdapterInvertWrapper.getConnection(DataSourceAdapterInvertWrapper.java.153)

com.fr.cbb.dialect.datasource.pool.DataSourceWrapper.getConnection(DataSourceWrapper.java.263)

com.fr.cbb.dialect.datasource.pool.MemoryConnection.create(MemoryConnection.java.187)

com.fr.cbb.dialect.datasource.DataSourceFactory.getConnection(DataSourceFactory.java.71)

com.fr.data.pool.MemoryConnection.create(MemoryConnection.java.125)

com.fr.data.auth.Authentication.authenticate(Authentication.java.50)

com.fr.data.auth.normal.NormalAuthentication.authenticate(NormalAuthentication.java.50)

com.fr.data.impl.JDBCDatabaseConnection.createConnection(JDBCDatabaseConnection.java.343)

com.fr.data.impl.JDBCDatabaseConnection.testConnection(JDBCDatabaseConnection.java.322)

com.fr.data.operator.DataOperator$8.call(DataOperator.java.-1)

com.fr.data.operator.DataOperator$8.call(DataOperator.java.-1)

java.util.concurrent.FutureTask.run(FutureTask.java.266)

java.util.concurrent.Executors$RunnableAdapter.call(Executors.java.511)

java.util.concurrent.FutureTask.run(FutureTask.java.266)

java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java.1149)

java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java.624)

java.lang.Thread.run(Thread.java.748)