最近公司买了阿里服务器，真他妈的的贵：
ECS： 4 核 8 G 50 内存 489/月 左右具体忘了,前期做外网测试。
RDS：mysql 5.5 低配置 89/月
注意点：
1:ECS 和 RDS 最好把分区分分到一块
2:本地测试一定要和开发环境的，jdk，mysql，tomcat （开发环境）保持一致。
以下是我因为以上的两个问题：遇到数据库链接错误日志
六月 19, 2015 1:26:03 下午 com.mchange.v2.resourcepool.BasicResourcePool 警告: Having failed to acquire a resource, com.mchange.v2.resourcepool.BasicResourcePool@6e55c2f is interrupting all Threads waiting on a resource to check out. Will try again in response to new client requests. 六月 19, 2015 1:26:18 下午 com.mchange.v2.resourcepool.BasicResourcePool 警告: com.mchange.v2.resourcepool.BasicResourcePool$ScatteredAcquireTask@32d06b64 -- 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.GeneratedConstructorAccessor27.newInstance(Unknown Source) at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) at java.lang.reflect.Constructor.newInstance(Constructor.java:422) at com.mysql.jdbc.Util.handleNewInstance(Util.java:389) at com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:1038) at com.mysql.jdbc.MysqlIO.readPacket(MysqlIO.java:627) at com.mysql.jdbc.MysqlIO.doHandshake(MysqlIO.java:1013) at com.mysql.jdbc.ConnectionImpl.coreConnect(ConnectionImpl.java:2239) at com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2270) at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2069) at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:794) at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:44) at sun.reflect.GeneratedConstructorAccessor24.newInstance(Unknown Source) at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) at java.lang.reflect.Constructor.newInstance(Constructor.java:422) at com.mysql.jdbc.Util.handleNewInstance(Util.java:389) at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:399) at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:325) at com.mchange.v2.c3p0.DriverManagerDataSource.getConnection(DriverManagerDataSource.java:175) at com.mchange.v2.c3p0.WrapperConnectionPoolDataSource.getPooledConnection(WrapperConnectionPoolDataSource.java:220) at com.mchange.v2.c3p0.WrapperConnectionPoolDataSource.getPooledConnection(WrapperConnectionPoolDataSource.java:206) at com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool$1PooledConnectionResourcePoolManager.acquireResource(C3P0PooledConnectionPool.java:200) at com.mchange.v2.resourcepool.BasicResourcePool.doAcquire(BasicResourcePool.java:1127) at com.mchange.v2.resourcepool.BasicResourcePool.doAcquireAndDecrementPendingAcquiresWithinLockOnSuccess(BasicResourcePool.java:1114) at com.mchange.v2.resourcepool.BasicResourcePool.access$800(BasicResourcePool.java:44) at com.mchange.v2.resourcepool.BasicResourcePool$ScatteredAcquireTask.run(BasicResourcePool.java:1855) at com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread.run(ThreadPoolAsynchronousRunner.java:696) Caused by: java.net.SocketException: Connection reset at java.net.SocketInputStream.read(SocketInputStream.java:209) at java.net.SocketInputStream.read(SocketInputStream.java:141) at com.mysql.jdbc.util.ReadAheadInputStream.fill(ReadAheadInputStream.java:100) at com.mysql.jdbc.util.ReadAheadInputStream.readFromUnderlyingStreamIfNecessary(ReadAheadInputStream.java:143) at com.mysql.jdbc.util.ReadAheadInputStream.read(ReadAheadInputStream.java:173) at com.mysql.jdbc.MysqlIO.readFully(MysqlIO.java:2911) at com.mysql.jdbc.MysqlIO.readPacket(MysqlIO.java:559) ... 21 more 六月 19, 2015 1:26:18 下午 com.mchange.v2.resourcepool.BasicResourcePool 警告: Having failed to acquire a resource, com.mchange.v2.resourcepool.BasicResourcePool@6e55c2f is interrupting all Threads waiting on a resource to check out. Will try again in response to new client requests. 六月 19, 2015 1:26:33 下午 com.mchange.v2.resourcepool.BasicResourcePool 警告: com.mchange.v2.resourcepool.BasicResourcePool$ScatteredAcquireTask@4a7a8cb4 -- 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.GeneratedConstructorAccessor27.newInstance(Unknown Source) at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) at java.lang.reflect.Constructor.newInstance(Constructor.java:422) at com.mysql.jdbc.Util.handleNewInstance(Util.java:389) at com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:1038) at com.mysql.jdbc.MysqlIO.readPacket(MysqlIO.java:627) at com.mysql.jdbc.MysqlIO.doHandshake(MysqlIO.java:1013) at com.mysql.jdbc.ConnectionImpl.coreConnect(ConnectionImpl.java:2239) at com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2270) at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2069) at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:794) at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:44) at sun.reflect.GeneratedConstructorAccessor24.newInstance(Unknown Source) at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) at java.lang.reflect.Constructor.newInstance(Constructor.java:422) at com.mysql.jdbc.Util.handleNewInstance(Util.java:389) at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:399) at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:325) at com.mchange.v2.c3p0.DriverManagerDataSource.getConnection(DriverManagerDataSource.java:175) at com.mchange.v2.c3p0.WrapperConnectionPoolDataSource.getPooledConnection(WrapperConnectionPoolDataSource.java:220) at com.mchange.v2.c3p0.WrapperConnectionPoolDataSource.getPooledConnection(WrapperConnectionPoolDataSource.java:206) at com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool$1PooledConnectionResourcePoolManager.acquireResource(C3P0PooledConnectionPool.java:200) at com.mchange.v2.resourcepool.BasicResourcePool.doAcquire(BasicResourcePool.java:1127) at com.mchange.v2.resourcepool.BasicResourcePool.doAcquireAndDecrementPendingAcquiresWithinLockOnSuccess(BasicResourcePool.java:1114) at com.mchange.v2.resourcepool.BasicResourcePool.access$800(BasicResourcePool.java:44) at com.mchange.v2.resourcepool.BasicResourcePool$ScatteredAcquireTask.run(BasicResourcePool.java:1855) at com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread.run(ThreadPoolAsynchronousRunner.java:696) Caused by: java.net.SocketException: Connection reset
前面排查了配置文件，架包很久，都找不到问题出在哪，最后在本地搭建了环境，和开发的一样，结果测试通过。后来检查了下数据库版本，fuck。开发用的是 5.6，RDS买的的是5.5。升级下通过了。
