logstash Error: com.mariadb.jdbc.Driver not loaded - logstash

Question

I'm trying to sync some tables from MariaDB to ElasticSearch using LogStash.
I'm on a Debian Buster (10) Server
$ java -version
openjdk version "11.0.4" 2019-07-16
OpenJDK Runtime Environment (build 11.0.4+11-post-Debian-1deb10u1)
OpenJDK 64-Bit Server VM (build 11.0.4+11-post-Debian-1deb10u1, mixed mode, sharing)
$ mariadb --version
mariadb Ver 15.1 Distrib 10.3.15-MariaDB, for debian-linux-gnu (x86_64) using readline 5.2
$ /usr/share/logstash/bin/logstash --version
logstash 7.2.0
I tried different connectors :
$ ls -l /usr/share/java/
mariadb-java-client.jar
$ ls -l /etc/logstash/connectors/
mariadb-java-client-2.1.2.jar
mariadb-java-client-2.2.6.jar
mariadb-java-client-2.3.0.jar
mariadb-java-client-2.4.2.jar
mysql-connector-java-8.0.17.jar
Using "org.mariadb.jdbc.Driver" for mariadb connectors and "com.mysql.cj.jdbc.Driver" for mysql connector
$ cat /etc/logstash/conf.d/db-fr-bank.conf
input {
jdbc {
jdbc_connection_string => "jdbc:mariadb://localhost:3306/db_fr"
jdbc_user => "logstash"
jdbc_password => "<password>"
jdbc_driver_library => "/usr/share/java/mariadb-java-client.jar"
jdbc_driver_class => "org.mariadb.jdbc.Driver"
statement => "SELECT * FROM bank"
}
}
output {
elasticsearch {
hosts => "localhost:9200"
index => "fr-bank"
}
}
But, instead of syncing, i keep getting :
$ /usr/share/logstash/bin/logstash -f /etc/logstash/conf.d/db-fr-bank.conf
...
[ERROR] 2019-07-29 02:08:17.563 [[main]<jdbc] jdbc - Failed to load /usr/share/java/mariadb-java-client.jar {:exception=>#<TypeError: failed to coerce jdk.internal.loader.ClassLoaders$AppClassLoader to java.net.URLClassLoader>}
[ERROR] 2019-07-29 02:08:17.598 [[main]<jdbc] javapipeline - A plugin had an unrecoverable error. Will restart this plugin.
Pipeline_id:main
Plugin: <LogStash::Inputs::Jdbc jdbc_user=>"logstash", jdbc_password=><password>, statement=>"SELECT * FROM bank", jdbc_driver_library=>"/usr/share/java/mariadb-java-client.jar", jdbc_connection_string=>"jdbc:mariadb://localhost:3306/db_fr", id=>"38a6d112755a5e87278761cf5f41b7e509212d1d02837a03672df2face00943a", jdbc_driver_class=>"org.mariadb.jdbc.Driver", enable_metric=>true, codec=><LogStash::Codecs::Plain id=>"plain_f3094292-7482-4b73-95c4-7f78da4da911", enable_metric=>true, charset=>"UTF-8">, jdbc_paging_enabled=>false, jdbc_page_size=>100000, jdbc_validate_connection=>false, jdbc_validation_timeout=>3600, jdbc_pool_timeout=>5, sql_log_level=>"info", connection_retry_attempts=>1, connection_retry_attempts_wait_time=>0.5, parameters=>{"sql_last_value"=>1970-01-01 00:00:00 UTC}, last_run_metadata_path=>"/root/.logstash_jdbc_last_run", use_column_value=>false, tracking_column_type=>"numeric", clean_run=>false, record_last_run=>true, lowercase_column_names=>true>
Error: org.mariadb.jdbc.Driver not loaded. Are you sure you've included the correct jdbc driver in :jdbc_driver_library?
Exception: LogStash::ConfigurationError
Stack: /usr/share/logstash/vendor/bundle/jruby/2.5.0/gems/logstash-input-jdbc-4.3.13/lib/logstash/plugin_mixins/jdbc/jdbc.rb:163:in `open_jdbc_connection'
/usr/share/logstash/vendor/bundle/jruby/2.5.0/gems/logstash-input-jdbc-4.3.13/lib/logstash/plugin_mixins/jdbc/jdbc.rb:221:in `execute_statement'
/usr/share/logstash/vendor/bundle/jruby/2.5.0/gems/logstash-input-jdbc-4.3.13/lib/logstash/inputs/jdbc.rb:277:in `execute_query'
/usr/share/logstash/vendor/bundle/jruby/2.5.0/gems/logstash-input-jdbc-4.3.13/lib/logstash/inputs/jdbc.rb:263:in `run'
/usr/share/logstash/logstash-core/lib/logstash/java_pipeline.rb:309:in `inputworker'
/usr/share/logstash/logstash-core/lib/logstash/java_pipeline.rb:302:in `block in start_input'
...

Answer 1

Same issue here.
I use the workaround from here with this and it works.
ie:
Copy the driver file to {logstash install dir}/logstash-core/lib/jars/ directory. These jars get added to the correct JDK classpath as logstash is started via java.
And
Change the jdbc_driver_library value in the logstash conf to "". i.e.: jdbc_driver_library => "" as well, otherwise the code still tries to load the jar separately