[MXS-4458] Many Unknown prepared statement handler (7) given to MaxScale for COM_STMT_EXECUTE warnings after upgrade to 6.4 and 22.08 Created: 2022-12-19  Updated: 2023-03-10  Resolved: 2022-12-19

Status: Closed
Project: MariaDB MaxScale
Component/s: N/A
Affects Version/s: 22.08.3
Fix Version/s: N/A

Type: Bug Priority: Major
Reporter: Naresh Chandra Assignee: Unassigned
Resolution: Not a Bug Votes: 0
Labels: None


 Description   

We are getting a lot of alerts in the maxscale log with the below warnings after we upgrade to 6.1 and 22.08 versions.

But the warning is started from Maxscale 6 version. But we don't see these errors in the previous versions like 2.5 and before 2.5 versions.

2022-12-19 02:01:24 warning: (3375914) (server1); Unknown prepared statement handler (7) given to MaxScale for COM_STMT_EXECUTE by 'test_app_usr'@'192.168.101.1'
2022-12-19 02:01:25 warning: (3375717) (server1); Unknown prepared statement handler (7) given to MaxScale for COM_STMT_EXECUTE by 'test_app_usr'@'192.168.101.2'
2022-12-19 02:01:25 warning: (3375717) (server1); Unknown prepared statement handler (7) given to MaxScale for COM_STMT_EXECUTE by 'test_app_usr'@'192.168.101.2'
2022-12-19 02:01:26 warning: (3375914) (server1); Unknown prepared statement handler (7) given to MaxScale for COM_STMT_EXECUTE by 'test_app_usr'@'192.168.101.1'
2022-12-19 02:02:17 warning: (3375914) (server1); Unknown prepared statement handler (7) given to MaxScale for COM_STMT_EXECUTE by 'test_app_usr'@'192.168.101.1'
2022-12-19 02:02:18 warning: (3375716) (server1); Unknown prepared statement handler (12) given to MaxScale for COM_STMT_EXECUTE by 'test_app_usr'@'192.168.101.2'
2022-12-19 02:02:19 warning: (3375914) (server1); Unknown prepared statement handler (7) given to MaxScale for COM_STMT_EXECUTE by 'test_app_usr'@'192.168.101.1'
2022-12-19 02:02:20 warning: (3375716) (server1); Unknown prepared statement handler (12) given to MaxScale for COM_STMT_EXECUTE by 'test_app_usr'@'192.168.101.2'
2022-12-19 02:02:20 warning: (3375914) (server1); Unknown prepared statement handler (7) given to MaxScale for COM_STMT_EXECUTE by 'test_app_usr'@'192.168.101.1'
2022-12-19 02:02:20 warning: (3375716) (server1); Unknown prepared statement handler (12) given to MaxScale for COM_STMT_EXECUTE by 'test_app_usr'@'192.168.101.2'
2022-12-19 02:02:20 warning: (3375914) (server1); Unknown prepared statement handler (7) given to MaxScale for COM_STMT_EXECUTE by 'test_app_usr'@'192.168.101.1'
2022-12-19 02:02:24 warning: (3375914) (server1); Unknown prepared statement handler (7) given to MaxScale for COM_STMT_EXECUTE by 'test_app_usr'@'192.168.101.1'
2022-12-19 02:02:28 warning: (3375914) (server1); Unknown prepared statement handler (7) given to MaxScale for COM_STMT_EXECUTE by 'test_app_usr'@'192.168.101.1'

 Comments   
Comment by markus makela [ 2022-12-19 ]

What driver are you using to connect to MaxScale?

Comment by Naresh Chandra [ 2022-12-19 ]

It's a MariaDB Connector/JDBC.

Comment by Naresh Chandra [ 2022-12-19 ]

Here are the driver details.

<dependency>
<groupId>org.mariadb.jdbc</groupId>
<artifactId>mariadb-java-client</artifactId>
<version>1.5.9</version>
</dependency>

Comment by markus makela [ 2022-12-19 ]

This is caused by CONJ-475, please upgrade the driver.

Comment by Diego Dupin [ 2022-12-19 ]

hi naresh.chandra@copart.com this is surely java connector related, with correction in https://jira.mariadb.org/browse/CONJ-475, corrected in 1.6.3/2.1.0 version. Anyway, version 1.x is not supported anymore, since 2.x is compatible (3.x is even out now). I would recommand to update driver to a much more recent version.

Comment by Naresh Chandra [ 2022-12-19 ]

Hi Diego and Markus,

Thanks for the update.

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