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Weblogic datasource using Denodo driver connection issues

hi All, we are trying to use the weblogic datasource to connect to denodo with the help of the denodo drivers. However only the first connection using datasource fetches the values from queries and all subsequent connections after closing the first call are resulting in "Internal server error No records returned" message. Request any suggestions or solutions if such things were already encountered previously.
user
14-07-2023 10:09:03 -0400
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4 Answers

Hi, I’ve found a similar question linked [here](https://community.denodo.com/answers/question/details?questionId=906Du00000000tXIAQ&title=java.sql.SQLException%3A+Internal+error+executing+query.+No+results+returned). The answer says that it seems like there’s a connection issue between your Denodo Virtual DataPort Server and your client application Weblogic. The “No results error” is usually a secondary error thrown as a result of a primary error like connection issue or credentials issue. I recommend taking note of the primary error first. First, you can go to **Denodo Designer Studio** or **Virtual DataPort Administration Tool**, and try to query the table if it’s returning any result or if it is throwing an exception. This will eliminate the underlying data source and the Denodo server as the issue. Second, if you’re using the JDBC driver for **Denodo 8.0 update 20220815**, check if your Denodo Virtual DataPort server is the same version or higher. It is recommended to use the version of Denodo JDBC driver that is the same as your Denodo server. Lastly, you can change the parameter **connectTimeout**, which by default, waits 120 seconds to establish a connection, to something higher. This can resolve the closed connection issue you’re getting. I recommend checking out this [User Guide](https://community.denodo.com/docs/html/browse/8.0/en/vdp/developer/access_through_jdbc/parameters_of_the_jdbc_connection_url/parameters_of_the_jdbc_connection_url) about the different JDBC connection parameters to know more. Hope this helps!
Denodo Team
17-07-2023 04:02:31 -0400
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thanks for your response , i have verified the denodo driver used at weblogic and found it to be fine. Also i would like to clarify that after weblogic server start, first request to denodo works however subsequent queies fail with the internal server error. We are using a client application which utilizes the weblogic datasource to connect to denodo and execute the query. If we utilize a direct jndi connection from client then we are not facing this issue, however the client requires the weblogic datasource way of communicating with denodo. If any sample client program or any settings to take care at weblogic level or client level would be appreciated.
user
 Edited on: 17-07-2023 13:01:30 -0400
Hi, I’d check the [How to access to VDP from OBIEE via JDBC](https://community.denodo.com/kb/en/view/document/How%20to%20access%20to%20VDP%20from%20OBIEE%20via%20JDBC) Denodo article and the [Access Through JDBC](https://community.denodo.com/docs/html/browse/latest/en/vdp/developer/access_through_jdbc/access_through_jdbc) section of the Virtual DataPort Developer Guide. Hope this helps!
Denodo Team
19-07-2023 05:32:16 -0400
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hi team, thanks for the info. We are able to establish the connection via jdbc datasource to denodo from weblogic. However the issue which we are facing is something different . After setup of jdbc connection if we try to create a connection using the jdbc from the java program then only the first program run works. The next re-run of same program after a while is resulting in Internal server error. after this error if we reboot the datasource and perform the program execution then it works again. this cycle continous and only once the execution works.
user
19-07-2023 08:51:09 -0400
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