I should also note my docker deployment has a connect.cnf defined as the following:

[mariadb]

plugin-load-add=ha_connect.so

connect_jvm_path=”/usr/lib/jvm/java-1.8.0-openjdk-amd64/jre/lib/amd64/server”

connect_class_path=”/usr/lib/mysql/plugin:/usr/lib/jvm/java-1.8.0-openjdk-amd64/jre/lib/ext/”

The error "ERROR 1296 (HY000): Got error 174 'ERROR: class /usr/lib/mysql/plugin/JavaWrappers.jar not found!' from CONNECT" is from the failed env->findClass which according to the Java classloader API takes a binary name and not a jar path file which is what it is called with.

Looking at the connect test cases connect_class_path is set to include the JavaWrappers.jar file which might work around the problem.

Note on your Dockerfile, "mariadb_repo_setup" isn't needed. The MariaDB repos are already configured in the container, after apt-get update, the mariadb-plugin-connect is installable. The lack of packaging of JavaWrappers.jar is MDEV-26218.

So three bugs:

• lack of packaging of JavaWrappers.jar - MDEV-26218
• poor Connect code attemps to load the JarWrappers.jar file as a class, which generates a confusing error message (this bug)
• user/documentation error, connect_class_path should include the JavaWrappers.jar file.

Hi Daniel,

With that in mind I've attempted to change the connect_class_path to attempt a work around in the mean time.

I've tried the following two cases: include the jar file and include the jar folder. Unfortunately, both resulting in the same error.

MariaDB [test]> set global connect_class_path="/usr/lib/jvm/java-1.8.0-openjdk-amd64/jre/lib/ext/JavaWrappers.jar:/usr/lib/mysql/plugin";

MariaDB [test]> alter table sample engine=InnoDB;

ERROR 1296 (HY000): Got error 174 'ERROR: class wrappers/JdbcInterface not found!' from CONNECT

MariaDB [test]> set global connect_class_path="/usr/lib/jvm/java-1.8.0-openjdk-amd64/jre/lib/ext:/usr/lib/mysql/plugin";

MariaDB [test]> alter table sample engine=InnoDB;

ERROR 1296 (HY000): Got error 174 'ERROR: class wrappers/JdbcInterface not found!' from CONNECT

Upon closer examination the error is different. I suspect it needs https://github.com/MariaDB/server/blob/10.11/storage/connect/mysql-test/connect/std_data/JdbcMariaDB.jar in the connect_class_path too.

Good morning.

I included the JdbcMariaDB. jar file in the directory usr/lib/mysql/plugin as seen below:

I then set the globals to include JdbcMariaDB.jar. But I get the same error.

set global connect_class_path="usr/lib/mysql/plugin/JavaWrappers.jar:usr/lib/mysql/plugin/JdbcMariaDB.jar:/usr/lib/mysql/plugin";

MariaDB [test]> alter table sample engine=InnoDB;

ERROR 1296 (HY000): Got error 174 'ERROR: class wrappers/JdbcInterface not found!' from CONNECT

It seems like this is a debian related issue. In the mean time do you think I can bypass this issue by creating a dockerfile for rockylinux and executing mariadb connect from there instead?

I think the issue based on your screen shot is there is no global read permissions on the jar files in the /usr/lib/mysql/plugins directory and they are root owned. MariaDB is starting as the mysql user so won't be able to read these.

I checked the jar file and the class is there.

jar -tvf JdbcMariaDB.jar | more

  2510 Sun Nov 27 14:29:38 SGT 2016 META-INF/MANIFEST.MF

     0 Thu Nov 24 18:33:48 SGT 2016 wrappers/

  2245 Thu Nov 24 18:33:48 SGT 2016 wrappers/MariadbInterface.class

  2238 Thu Nov 24 18:33:48 SGT 2016 wrappers/OracleInterface.class

  2286 Thu Nov 24 18:33:48 SGT 2016 wrappers/PostgresqlInterface.class

 17099 Thu Nov 24 18:33:48 SGT 2016 wrappers/JdbcInterface.class

  2304 Thu Nov 24 18:33:48 SGT 2016 wrappers/ApacheInterface.class

  5375 Thu Nov 24 18:33:48 SGT 2016 wrappers/Client.class

  2233 Thu Nov 24 18:33:48 SGT 2016 wrappers/MysqlInterface.class

  1776 Sat Jul 16 23:03:00 SGT 2016 wrappers/HikariCPInterface.Copie

...

Good point. I provided read and changed ownership to mysql:

chown -R mysql:mysql /usr/lib/mysql/plugin

chmod o+r /usr/lib/mysql/plugin/*.jar

chown -R mysql:mysql /usr/lib/mysql

I now arrive at a different error.

MariaDB [test]> set global connect_class_path="/usr/lib/mysql/pluginJavaWrappers.jar:/usr/lib/mysql/pluginJdbcMariaDB.jar:/usr/lib/mysql/plugin";

Query OK, 0 rows affected (0.000 sec)

MariaDB [test]> alter table sample engine=InnoDB;

ERROR 1296 (HY000): Got error 174 'ERROR: class /usr/lib/mysql/plugin/ not found!' from CONNECT

Alternatively, I tried to only include the jar files but the same error occured. " set global connect_class_path="/usr/lib/mysql/pluginJavaWrappers.jar:/usr/lib/mysql/pluginJdbcMariaDB.jar"

I found this page which details how to check classpath. Checking classpath I get null. Is this another issue?

MariaDB [test]> create function envar returns string soname 'ha_connect.so';

Query OK, 0 rows affected (0.008 sec)

MariaDB [test]> select envar('CLASSPATH');

+--------------------+

| envar('CLASSPATH') |

+--------------------+

| NULL               |

+--------------------+

Hi,
before we start let's check do you have loaded connect SE, run select plugin_name from information_schema.plugins where plugin_name='connect';.
If it is loaded, restart your container docker restart <cont-name>.
What you should do are following steps:
1. check jvm file path
2. check Javawrapper.jar file path
and make sure they are correct, I suppose this is not correct from your configuration "/usr/lib/mysql/pluginJavaWrappers.jar", missing `/`, right ?
After that:
3. check the path of you JDBC mariadb client
4. add it to your class path connect_class_path together with Javawrapper.jar file
5. don't care about envar('classpath')
6. try example from documentation to create the table with {{mariadb}}JDBC and proper authentication. It should work.
If doesn't work please add results from all above steps to debug.

Hello. Thanks for the reply. The "/" was a typo but correcting it had similar results. So I followed your instructions to ensure it was correct. Im using Kubernetes with Helm so after checking whether connect was installed I restarted with the following:

# restarting pod from current directory

restart helm upgrade --recreate-pods -i my-maria-a .

MariaDB [test]>  select plugin_name from information_schema.plugins where plugin_name='connect';

+-------------+

| plugin_name |

+-------------+

| CONNECT     |

+-------------+

1. check jvm file path

root@my-maria-b-deployment-7dd78565d9-r7mcq:/# echo $JAVA_HOME

root@my-maria-b-deployment-7dd78565d9-r7mcq:/# which java

/usr/bin/java

root@my-maria-b-deployment-7dd78565d9-r7mcq:/# readlink -f /usr/bin/java

/usr/lib/jvm/java-8-openjdk-amd64/jre/bin/java

root@my-maria-b-deployment-7dd78565d9-r7mcq:/usr/lib/mysql/plugin# set global connect_jvm_path="/usr/lib/jvm/java-8-openjdk-amd64/jre/bin/java:/usr/lib/mysql/plugin";

2. check Javawrapper.jar file path and check the path of you JDBC mariadb client

root@my-maria-b-deployment-7dd78565d9-r7mcq:/usr/lib/mysql/plugin# ll /usr/lib/mysql/plugin/*.jar

-rw-r--r-- 1 mysql mysql   44053 Apr  4 22:47 /usr/lib/mysql/plugin/JavaWrappers.jar

-rw-r--r-- 1 mysql mysql 6021947 Apr 10 16:24 /usr/lib/mysql/plugin/JdbcMariaDB.jar

-rw-r--r-- 1 mysql mysql  638356 Apr  4 17:44 /usr/lib/mysql/plugin/mariadb-java-client-3.1.3.jar

3. check the path of you JDBC mariadb client

root@my-maria-b-deployment-7dd78565d9-r7mcq:/usr/lib/mysql/plugin# set global connect_class_path="/usr/lib/mysql/plugin/JavaWrappers.jar:/usr/lib/mysql/plugin/mariadb-java-client-3.1.3.jar";

The example below was an adaptation from the docs (although I cannot find the link). It is similar to the SO instructions in the answer.

MariaDB [test]> drop table sample;

Query OK, 0 rows affected (0.005 sec)

MariaDB [test]> drop table sample_server1;

Query OK, 0 rows affected (0.004 sec)

MariaDB [test]> create table sample_server1 ( bloodType varchar(100) not null) engine=CONNECT table_type=JDBC connection='jdbc:mariadb://10.50.6.101:3306/test?user=root&password=r00t';

Query OK, 0 rows affected (0.017 sec)

MariaDB [test]> create table sample like sample_server1;

Query OK, 0 rows affected (0.003 sec)

MariaDB [test]> alter table sample engine=InnoDB;

ERROR 1296 (HY000): Got error 174 'ERROR: class /usr/lib/mysql/plugin/ not found!' from CONNECT

Hi,
so you can create successfully table using JDBC, what was the purpose of MDEV right.

Regarding your additional error, I couldn't reproduce it.

• Source:

  MariaDB [db_maria]> create table sample (bloodType varchar(100) not null);

  Query OK, 0 rows affected (0.028 sec)

  MariaDB [db_maria]> INSERT INTO sample (bloodType) VALUES ("O"), ("A"), ("AB");

  MariaDB [db_maria]> select * from sample;

  +-----------+

  | bloodType |

  +-----------+

  | O |

  | A |

  | AB |

  +-----------+

• Target:

  MariaDB [test]> create table target_sample engine=connect table_type=JDBC tabname=sample connection='jdbc:mariadb://mariadb-source/db_maria?user=root&password';

  Query OK, 0 rows affected (0.014 sec)

  MariaDB [test]> select * from target_sample;

  +-----------+

  | bloodType |

  +-----------+

  | O |

  | A |

  | AB |

  +-----------+

  3 rows in set (0.003 sec)

  MariaDB [test]> create table target_sample_innodb like target_sample;

  Query OK, 0 rows affected (0.020 sec)

  MariaDB [test]> select * from target_sample_innodb;

  +-----------+

  | bloodType |

  +-----------+

  | O |

  | A |

  | AB |

  +-----------+

  3 rows in set (0.003 sec)

  Soon, we will publish the blog related to the JDBC and Connect.
  Feel free to create new MDEV related to new error, I will close this one .

Here is the blog post about https://mariadb.org/connect-se-jdbc-table-type-accessing-tables-from-another-dbms/