问题 Tomcat向Mysql发送请求时发生Socket异常。
一整天都会发生10次左右。由于它很少发生，这似乎是一个角落问题。关于如何进一步调试/修复它的任何输入？
设置详情 Linux上的Tomcat; MySQL的
堆栈跟踪
java.sql.SQLException: Communication link failure: java.net.SocketException, underlying cause: Connection timed out
开始嵌入异常
java.net.SocketException
消息：连接超时
堆栈跟踪：
java.net.SocketException: Connection timed out
at java.net.SocketInputStream.socketRead0(Native Method)
at java.net.SocketInputStream.read(SocketInputStream.java:146)
at com.mysql.jdbc.MysqlIO.readFully(MysqlIO.java:1392)
at com.mysql.jdbc.MysqlIO.reuseAndReadPacket(MysqlIO.java:1539)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:1930)
at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:1168)
at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:1279)
at com.mysql.jdbc.MysqlIO.sqlQuery(MysqlIO.java:1225)
at com.mysql.jdbc.Connection.execSQL(Connection.java:2278)
at com.mysql.jdbc.Connection.execSQL(Connection.java:2225)
at com.mysql.jdbc.Statement.executeQuery(Statement.java:1163)
at sun.reflect.GeneratedMethodAccessor47.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:622)
at org.apache.tomcat.jdbc.pool.interceptor.AbstractQueryReport$StatementProxy.invoke(AbstractQueryReport.ja
va:235)
at com.sun.proxy.$Proxy16.executeQuery(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1146)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at java.lang.Thread.run(Thread.java:701)
END NESTED EXCEPTION
at com.mysql.jdbc.MysqlIO.reuseAndReadPacket(MysqlIO.java:1714)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:1930)
at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:1168)
at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:1279)
at com.mysql.jdbc.MysqlIO.sqlQuery(MysqlIO.java:1225)
at com.mysql.jdbc.Connection.execSQL(Connection.java:2278)
at com.mysql.jdbc.Connection.execSQL(Connection.java:2225)
at com.mysql.jdbc.Statement.executeQuery(Statement.java:1163)
at sun.reflect.GeneratedMethodAccessor47.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:622)
at org.apache.tomcat.jdbc.pool.interceptor.AbstractQueryReport$StatementProxy.invoke(AbstractQueryReport.ja
va:235)
at com.sun.proxy.$Proxy16.executeQuery(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1146)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at java.lang.Thread.run(Thread.java:701)
答案 0 :(得分：0)
请确保您的应用程序在使用后关闭连接。如果您没有关闭连接，那么在一段时间后它将达到最大连接数。之后你就无法创建连接。只有在达到超时后，mysql才会关闭该连接（实际应该关闭）。之后，您可以使用该连接。所以请检查您的连接关闭代码。
答案 1 :(得分：0)