【发布时间】：2021-07-17 23:39:02
【问题描述】：
我有一个使用 Tomcat 和 MySQL 的生产服务器。今天所有网站都停止连接到各自的数据库。
重启Tomcat时，显示无法为所有网站/数据库创建连接池。这是错误日志（针对一个网站）：
23-Apr-2021 12:18:49.438 INFO [evaluaciones-grupocomidas.com-startStop-1] org.apache.catalina.startup.HostConfig.deployDescriptor Deploying configuration descriptor [/opt/tomcat/conf/Catalina/evaluaciones-grupocomidas.com/ROOT.xml]
23-Apr-2021 12:18:49.690 SEVERE [evaluaciones-grupocomidas.com-startStop-1] org.apache.tomcat.jdbc.pool.ConnectionPool.init Unable to create initial connections of pool.
com.mysql.cj.jdbc.exceptions.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 com.mysql.cj.jdbc.exceptions.SQLError.createCommunicationsException(SQLError.java:174)
at com.mysql.cj.jdbc.exceptions.SQLExceptionsMapping.translateException(SQLExceptionsMapping.java:64)
at com.mysql.cj.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:835)
at com.mysql.cj.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:455)
at com.mysql.cj.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:240)
at com.mysql.cj.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:199)
at org.apache.tomcat.jdbc.pool.PooledConnection.connectUsingDriver(PooledConnection.java:319)
at org.apache.tomcat.jdbc.pool.PooledConnection.connect(PooledConnection.java:212)
at org.apache.tomcat.jdbc.pool.ConnectionPool.createConnection(ConnectionPool.java:736)
at org.apache.tomcat.jdbc.pool.ConnectionPool.borrowConnection(ConnectionPool.java:668)
at org.apache.tomcat.jdbc.pool.ConnectionPool.init(ConnectionPool.java:483)
at org.apache.tomcat.jdbc.pool.ConnectionPool.<init>(ConnectionPool.java:154)
at org.apache.tomcat.jdbc.pool.DataSourceProxy.pCreatePool(DataSourceProxy.java:118)
at org.apache.tomcat.jdbc.pool.DataSourceProxy.createPool(DataSourceProxy.java:107)
at org.apache.tomcat.jdbc.pool.DataSourceFactory.createDataSource(DataSourceFactory.java:560)
at org.apache.tomcat.jdbc.pool.DataSourceFactory.getObjectInstance(DataSourceFactory.java:244)
at org.apache.naming.factory.FactoryBase.getObjectInstance(FactoryBase.java:94)
at javax.naming.spi.NamingManager.getObjectInstance(NamingManager.java:332)
at org.apache.naming.NamingContext.lookup(NamingContext.java:839)
at org.apache.naming.NamingContext.lookup(NamingContext.java:159)
at org.apache.naming.NamingContext.lookup(NamingContext.java:827)
at org.apache.naming.NamingContext.lookup(NamingContext.java:173)
at org.apache.catalina.core.NamingContextListener.addResource(NamingContextListener.java:1017)
at org.apache.catalina.core.NamingContextListener.createNamingContext(NamingContextListener.java:557)
at org.apache.catalina.core.NamingContextListener.lifecycleEvent(NamingContextListener.java:253)
at org.apache.catalina.util.LifecycleBase.fireLifecycleEvent(LifecycleBase.java:94)
at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5063)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:743)
at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:719)
at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:714)
at org.apache.catalina.startup.HostConfig.deployDescriptor(HostConfig.java:614)
at org.apache.catalina.startup.HostConfig$DeployDescriptor.run(HostConfig.java:1823)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
at java.lang.Thread.run(Thread.java:748)
Caused by: com.mysql.cj.exceptions.CJCommunicationsException: Communications link failure
而ROOT.xml的内容是：
<Resource
name="jdbc/rhwebDB"
auth="Container"
type="javax.sql.DataSource"
factory="org.apache.tomcat.jdbc.pool.DataSourceFactory"
testWhileIdle="true"
testOnBorrow="true"
testOnReturn="false"
validationQuery="SELECT 1"
validationInterval="30000"
timeBetweenEvictionRunsMillis="30000"
maxActive="5"
minIdle="0"
maxIdle="5"
maxWait="10000"
initialSize="2"
removeAbandonedTimeout="60"
removeAbandoned="true"
logAbandoned="true"
minEvictableIdleTimeMillis="30000"
username="grupocom_rhuser"
password="mypwd"
driverClassName="com.mysql.cj.jdbc.Driver"
url="jdbc:mysql://127.0.0.1:3306/grupocom_rhweb?serverTimezone=EST5EDT"/>
这个问题从今天开始，我已经没有办法了。也许几个月（或几年）都可以正常工作。
JDBC 驱动程序是：mysql-connector-java-8.0.16.jar（它位于 %CATALINA_HOME%/lib/ 下 MySQL版本为：5.7.34
我已经尝试从 url 参数中删除“serverTimezone”，使用服务器的 IP 而不是 127.0.0.1 和其他东西，但它仍然无法正常工作。
任何帮助将不胜感激
更新
我在另一个日志文件中发现了其余的异常，这可能是相关的：
Caused by: javax.net.ssl.SSLHandshakeException: No appropriate protocol (protocol is disabled or cipher suites are inappropriate)
at sun.security.ssl.HandshakeContext.<init>(HandshakeContext.java:171)
at sun.security.ssl.ClientHandshakeContext.<init>(ClientHandshakeContext.java:98)
at sun.security.ssl.TransportContext.kickstart(TransportContext.java:220)
at sun.security.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:428)
at com.mysql.cj.protocol.ExportControlled.performTlsHandshake(ExportControlled.java:316)
at com.mysql.cj.protocol.StandardSocketFactory.performTlsHandshake(StandardSocketFactory.java:188)
at com.mysql.cj.protocol.a.NativeSocketConnection.performTlsHandshake(NativeSocketConnection.java:99)
at com.mysql.cj.protocol.a.NativeProtocol.negotiateSSLConnection(NativeProtocol.java:352)
【问题讨论】：