sporadic database reader failures

Since upgrading to 3.7, I get sporadic database reader errors. An older workflow, with no problems before, suddenly stops reading and throws this error:
Execute failed: com/microsoft/sqlserver/jdbc/StreamError
If I close knime and re-open, the same workflow runs without errors. It seems to happen mostly when I let knime sit open for a while.

Hi,
can you please attache or send me the log file via PM which contains the error message. Maybe SQL Server is closing a connection if it is idle for a longer time.
Bye
Tobias

Actually the problem is happening with the Oracle readers too. What is PM?

Hi there!

I would say PM is Personal Message but maybe mistaken :slight_smile:

Br,
Ivan

Personal Message sounds right. How would one go about discovering a PA? (personal address)

Hi,
sorry about not telling you how to write a personal message. Just click on my forum name and you will see a Message button. Thanks for sending the log files.
Bye
Tobias

removed (3.2 MB)
I finally see the upload button here. Does that work for you?

Hi,
Yes, I have downloaded the log file and removed it from your post. I will have a look at it right away.
Tobias

Hi,
I couldn’t find any StreamError in the attached log files. I only could find the following error related to MS SQL Server:

2019-01-25 14:01:03,896 : DEBUG : KNIME-Worker-3 : SQLServerUtility : Database Reader : 0:1411 : Microsoft JDBC Driver For SQL Server seems not to be installed
java.lang.ClassNotFoundException: com.microsoft.sqlserver.jdbc.SQLServerDriver cannot be found by org.knime.database.connectors_3.7.0.v201808081048

Have you installed the extension with the Microsoft JDBC driver (as shown in the attached picture)?


To install it simply open KNIME and go to File->Install KNIME Extensions…
If you want to send me another log file please use the personal message button when you click on my account name since the log file contains database urls. In the personal message window you can also upload file by using the upload button (see below).

Bye
Tobias

Yes. That extension is already installed. Actually, I’m not sure it’s a real error. That’s the reason that it’s so frustrating. If I let knime sit there a while, an hour or so, the database readers stop working. I have to close down and restart. Then, as long as I’m running or working on something, there are no interruptions.

Log files deleted by admin.

the problem persits. Please take a look at the console and log I am sending. I close and re open knime and the problem is gone for a while. Thanks for reviewing!