MySQL connector error (Communications link failure)

KNIME Analytics Platform
1

Hi all,

After updating to the newest version of Knime MySQL connector stopped working and I receive this error everytime I try to join:

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image1211×57 2.51 KB

Some info:

  • I am using Knime in virtual machine to connect to this database. I recently updated Knime from a version that was 2 years old

  • Connection to the database worked fine before and I am able to connect to it through HeidiSQL - seems that the problem is coming from Knime side

  • I have tried all the different drivers for MySQL connector

  • Also looked at similar errors, however was not able to find a solution

  • Other MySQL connections work fine

Any solutions? Thanks in advance!

2

Hey Wytux10,

The typical issue is that the MySQL server is not accessible from the machine where KNIME is operating.

Some questions to consider include: is HeidiSQL operating on the same machine as KNIME AP? If so, does it utilize the same driver version? Could you please provide the complete error message from the KNIME log?

1 Like
3

Yes, HeidiSQL and Knime are run on the same virtual machine.

Regarding the drivers - I am less experienced and I am not fully sure. In HeidiSQL I am using these:
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Here is detailed log:

2023-02-23 11:31:59,685 : ERROR : KNIME-Worker-21-MySQL Connector 3:288 :  : Node : MySQL Connector : 3:288 : Execute failed: 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.
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:828)
	at com.mysql.cj.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:448)
	at com.mysql.cj.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:241)
	at com.mysql.cj.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:198)
	at org.knime.database.connection.UrlDBConnectionController$ControlledDriver.connect(UrlDBConnectionController.java:103)
	at org.knime.database.connection.UrlDBConnectionController.connect(UrlDBConnectionController.java:368)
	at org.knime.database.connection.UserDBConnectionController.connect(UserDBConnectionController.java:294)
	at org.knime.database.connection.UrlDBConnectionController.createConnection(UrlDBConnectionController.java:348)
	at org.knime.database.connection.AbstractConnectionProvider.createConnection(AbstractConnectionProvider.java:103)
	at org.knime.database.connection.impl.DBConnectionManager.lambda$2(DBConnectionManager.java:501)
	at java.base/java.util.concurrent.FutureTask.run(Unknown Source)
	at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
	at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
	at java.base/java.lang.Thread.run(Unknown Source)
Caused by: com.mysql.cj.exceptions.CJCommunicationsException: 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 java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
	at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
	at java.base/jdk.internal.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
	at java.base/java.lang.reflect.Constructor.newInstanceWithCaller(Unknown Source)
	at java.base/java.lang.reflect.Constructor.newInstance(Unknown Source)
	at com.mysql.cj.exceptions.ExceptionFactory.createException(ExceptionFactory.java:61)
	at com.mysql.cj.exceptions.ExceptionFactory.createException(ExceptionFactory.java:105)
	at com.mysql.cj.exceptions.ExceptionFactory.createException(ExceptionFactory.java:151)
	at com.mysql.cj.exceptions.ExceptionFactory.createCommunicationsException(ExceptionFactory.java:167)
	at com.mysql.cj.protocol.a.NativeProtocol.negotiateSSLConnection(NativeProtocol.java:378)
	at com.mysql.cj.protocol.a.NativeAuthenticationProvider.connect(NativeAuthenticationProvider.java:205)
	at com.mysql.cj.protocol.a.NativeProtocol.connect(NativeProtocol.java:1433)
	at com.mysql.cj.NativeSession.connect(NativeSession.java:133)
	at com.mysql.cj.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:948)
	at com.mysql.cj.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:818)
	... 13 more
Caused by: javax.net.ssl.SSLHandshakeException: Remote host terminated the handshake
	at java.base/sun.security.ssl.SSLSocketImpl.handleEOF(Unknown Source)
	at java.base/sun.security.ssl.SSLSocketImpl.decode(Unknown Source)
	at java.base/sun.security.ssl.SSLSocketImpl.readHandshakeRecord(Unknown Source)
	at java.base/sun.security.ssl.SSLSocketImpl.startHandshake(Unknown Source)
	at java.base/sun.security.ssl.SSLSocketImpl.startHandshake(Unknown Source)
	at com.mysql.cj.protocol.ExportControlled.performTlsHandshake(ExportControlled.java:347)
	at com.mysql.cj.protocol.StandardSocketFactory.performTlsHandshake(StandardSocketFactory.java:191)
	at com.mysql.cj.protocol.a.NativeSocketConnection.performTlsHandshake(NativeSocketConnection.java:101)
	at com.mysql.cj.protocol.a.NativeProtocol.negotiateSSLConnection(NativeProtocol.java:369)
	... 18 more
	Suppressed: java.net.SocketException: An established connection was aborted by the software in your host machine
		at java.base/sun.nio.ch.NioSocketImpl.implWrite(Unknown Source)
		at java.base/sun.nio.ch.NioSocketImpl.write(Unknown Source)
		at java.base/sun.nio.ch.NioSocketImpl$2.write(Unknown Source)
		at java.base/java.net.Socket$SocketOutputStream.write(Unknown Source)
		at java.base/sun.security.ssl.SSLSocketOutputRecord.encodeAlert(Unknown Source)
		at java.base/sun.security.ssl.TransportContext.fatal(Unknown Source)
		at java.base/sun.security.ssl.TransportContext.fatal(Unknown Source)
		... 24 more
Caused by: java.io.EOFException: SSL peer shut down incorrectly
	at java.base/sun.security.ssl.SSLSocketInputRecord.read(Unknown Source)
	at java.base/sun.security.ssl.SSLSocketInputRecord.readFully(Unknown Source)
	at java.base/sun.security.ssl.SSLSocketInputRecord.decodeInputRecord(Unknown Source)
	at java.base/sun.security.ssl.SSLSocketInputRecord.decode(Unknown Source)
	at java.base/sun.security.ssl.SSLTransport.decode(Unknown Source)
	... 26 more
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