关于Caused by: java.net.SocketException: Permission denied: connect问题的处理

 今日处理一个Permission denied的问题，现象：此应用为一采集器，项目经理反馈说是经常性的自己就挂掉了，让协助排查下；环境为：windows2008+jdk1.8，网上参考了很多解决办法，很多基本都不符合我这里情况，最后找到一些关于java通讯网络偏好的一些参考建议，觉得这个应该是符合我这里环境，先做了配置，然后观察段时间。

[SPIDER] 2018-10-10 00:00:00,080 [WARN ] resourcepool.BasicResourcePool - com.mchange.v2.resourcepool.BasicResourcePool$ScatteredAcquireTask@2d133ed7 -- Acquisition Attempt Failed!!! Clearing pending acquires. While trying to acquire a needed new resource, we failed to succeed more than the maximum number of allowed acquisition attempts (30). Last acquisition attempt exception: 
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 received any packets from the server.
	at sun.reflect.GeneratedConstructorAccessor112.newInstance(Unknown Source)
	at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
	at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
	at com.mysql.jdbc.Util.handleNewInstance(Util.java:411)
	at com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:1116)
	at com.mysql.jdbc.MysqlIO.(MysqlIO.java:344)
	at com.mysql.jdbc.ConnectionImpl.coreConnect(ConnectionImpl.java:2332)
	at com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2369)
	at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2153)
	at com.mysql.jdbc.ConnectionImpl.(ConnectionImpl.java:792)
	at com.mysql.jdbc.JDBC4Connection.(JDBC4Connection.java:47)
	at sun.reflect.GeneratedConstructorAccessor108.newInstance(Unknown Source)
	at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
	at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
	at com.mysql.jdbc.Util.handleNewInstance(Util.java:411)
	at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:381)
	at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:305)
	at com.mchange.v2.c3p0.DriverManagerDataSource.getConnection(DriverManagerDataSource.java:146)
	at com.mchange.v2.c3p0.WrapperConnectionPoolDataSource.getPooledConnection(WrapperConnectionPoolDataSource.java:195)
	at com.mchange.v2.c3p0.WrapperConnectionPoolDataSource.getPooledConnection(WrapperConnectionPoolDataSource.java:184)
	at com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool$1PooledConnectionResourcePoolManager.acquireResource(C3P0PooledConnectionPool.java:200)
	at com.mchange.v2.resourcepool.BasicResourcePool.doAcquire(BasicResourcePool.java:1086)
	at com.mchange.v2.resourcepool.BasicResourcePool.doAcquireAndDecrementPendingAcquiresWithinLockOnSuccess(BasicResourcePool.java:1073)
	at com.mchange.v2.resourcepool.BasicResourcePool.access$800(BasicResourcePool.java:44)
	at com.mchange.v2.resourcepool.BasicResourcePool$ScatteredAcquireTask.run(BasicResourcePool.java:1810)
	at com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread.run(ThreadPoolAsynchronousRunner.java:648)
Caused by: java.net.SocketException: Permission denied: connect
	at java.net.DualStackPlainSocketImpl.connect0(Native Method)
	at java.net.DualStackPlainSocketImpl.socketConnect(DualStackPlainSocketImpl.java:79)
	at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:350)
	at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:206)
	at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:188)
	at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:172)
	at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392)
	at java.net.Socket.connect(Socket.java:589)
	at java.net.Socket.connect(Socket.java:538)
	at java.net.Socket.(Socket.java:434)
	at java.net.Socket.(Socket.java:244)
	at com.mysql.jdbc.StandardSocketFactory.connect(StandardSocketFactory.java:257)
	at com.mysql.jdbc.MysqlIO.(MysqlIO.java:294)
	... 20 more

调整办法：修改JVM的运行参数增加如下内容在catalina.sh中

JAVA_OPTS=" -Djava.net.preferIPv4Stack=true"