CommunicationsException: Communications link failure

[ALin202305]

可以通过java接口写代码访问数据库，dolphin创建数据源成功，同版本的其他数据源访问成功，但是最近新加入的这一批数据源全部出现了下面的问题。
[ERROR] 2023-05-30 02:18:14.436 +0000 - sql task error
com.google.common.util.concurrent.UncheckedExecutionException: java.lang.RuntimeException: JDBC connect failed
at com.google.common.cache.LocalCache$Segment.get(LocalCache.java:2055)
at com.google.common.cache.LocalCache.get(LocalCache.java:3966)
at com.google.common.cache.LocalCache$LocalManualCache.get(LocalCache.java:4863)
at org.apache.dolphinscheduler.plugin.datasource.api.plugin.DataSourceClientProvider.getConnection(DataSourceClientProvider.java:73)
at org.apache.dolphinscheduler.plugin.task.sql.SqlTask.executeFuncAndSql(SqlTask.java:193)
at org.apache.dolphinscheduler.plugin.task.sql.SqlTask.handle(SqlTask.java:161)
at org.apache.dolphinscheduler.server.worker.runner.DefaultWorkerDelayTaskExecuteRunnable.executeTask(DefaultWorkerDelayTaskExecuteRunnable.java:49)
at org.apache.dolphinscheduler.server.worker.runner.WorkerTaskExecuteRunnable.run(WorkerTaskExecuteRunnable.java:174)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
at com.google.common.util.concurrent.TrustedListenableFutureTask$TrustedFutureInterruptibleTask.runInterruptibly(TrustedListenableFutureTask.java:131)
at com.google.common.util.concurrent.InterruptibleTask.run(InterruptibleTask.java:74)
at com.google.common.util.concurrent.TrustedListenableFutureTask.run(TrustedListenableFutureTask.java:82)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
at java.lang.Thread.run(Thread.java:748)
Caused by: java.lang.RuntimeException: JDBC connect failed
at org.apache.dolphinscheduler.plugin.datasource.api.client.CommonDataSourceClient.checkClient(CommonDataSourceClient.java:98)
at org.apache.dolphinscheduler.plugin.datasource.api.client.CommonDataSourceClient.(CommonDataSourceClient.java:54)
at org.apache.dolphinscheduler.plugin.datasource.mysql.MySQLDataSourceClient.(MySQLDataSourceClient.java:27)
at org.apache.dolphinscheduler.plugin.datasource.mysql.MySQLDataSourceChannel.createDataSourceClient(MySQLDataSourceChannel.java:29)
at org.apache.dolphinscheduler.plugin.datasource.api.plugin.DataSourceClientProvider.lambda$getConnection$1(DataSourceClientProvider.java:79)
at com.google.common.cache.LocalCache$LocalManualCache$1.load(LocalCache.java:4868)
at com.google.common.cache.LocalCache$LoadingValueReference.loadFuture(LocalCache.java:3533)
at com.google.common.cache.LocalCache$Segment.loadSync(LocalCache.java:2282)
at com.google.common.cache.LocalCache$Segment.lockedGetOrLoad(LocalCache.java:2159)
at com.google.common.cache.LocalCache$Segment.get(LocalCache.java:2049)
... 14 common frames omitted
Caused by: org.springframework.jdbc.CannotGetJdbcConnectionException: Failed to obtain JDBC Connection; nested exception is 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 org.springframework.jdbc.datasource.DataSourceUtils.getConnection(DataSourceUtils.java:83)
at org.springframework.jdbc.core.JdbcTemplate.execute(JdbcTemplate.java:376)
at org.springframework.jdbc.core.JdbcTemplate.execute(JdbcTemplate.java:431)
at org.apache.dolphinscheduler.plugin.datasource.api.client.CommonDataSourceClient.checkClient(CommonDataSourceClient.java:96)
... 23 common frames omitted
Caused by: 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.

[ALin202305]

因为连接的是阿里云服务器，端口什么的DBA也说有正常开启，但还是出现了上面的问题