Failed Connection Between Client and RapidMiner Server

Eric_Poitras

Hi,

I'm able to connect from the client to the server, but the folder structure from the server cannot be retrieved and displayed in the client. The connection status in RapidMiner studio is confirmed, but is still listed as pending. Meanwhile, Ive included the server log, and it seems that a table missing is at the cause of many issues detected. Anyone can help me out on how to fix this? Im a newbie at RapidMiner server.

rfuentealba

Hi @Eric_Poitras,

 

Though the log has been chopped (we can know due to the first line, saying "WARNING! This log was too long and therefore contains only the last 1000000 characters, please configure your JBoss to use rotational logs to prevent this from happening."), we do find something interesting in your logfile:

 

13:48:21,717 ERROR [org.apache.catalina.core.ContainerBase.[jboss.web].[ra-host].[/].[jdbcConnectionsServlet]] (http-/0.0.0.0:8080-3) JBWEB000236: Servlet.service() for servlet jdbcConnectionsServlet threw exception: java.sql.SQLSyntaxErrorException: Table 'rapidminer_server.ra_ent_dbconnectionentry' doesn't exist

 

For some reason, RapidMiner Server cannot connect to your database. I would check the following:

 

1.- Is the MySQL database up and running?

2.- Are the RapidMiner Server settings for that database correct?

3.- Is the JDBC driver for MySQL correct?

4.- Is there any issue with the connectivity between both?

5.- Are you entirely sure that you can see the table ra_ent_dbconnectionentry on that database?

6.- Are you sure your MySQL database accepts connections from other servers?

 

All of the problems I can see are caused by MySQL not responding properly, and this might be a serious problem yet I don't know how to proceed further without knowing how are you running RapidMiner Server.

 

Best,

 

Eric_Poitras

1.- Is the MySQL database up and running?

Yes - MySQL v8.0.11 running on Win Server 2012 R2

2.- Are the RapidMiner Server settings for that database correct?

I believe so. Rapidminer_server schema is in place with utf8_bin collation and utf8 characterset. "rmuser" user has caching_sha2_password, no account limits, all administrative roles and all available privileges to the rapidminer_server schema. Networking options show max_allowed_packet at 256M. All file locations are at default locations on the C: drive

3.- Is the JDBC driver for MySQL correct?

I believe so. Mysql-connector-java-8.0.11 installed and reported successful connection with MySQL server during installation (with root credentials)

4.- Is there any issue with the connectivity between both?

Unknown -- RapidMiner server installation reported success and startup of RM appeared to populate rapidminer_server schema with tables

5.- Are you entirely sure that you can see the table ra_ent_dbconnectionentry on that database?

No -- that table does not exist. Would love to know why not!

6.- Are you sure your MySQL database accepts connections from other servers?

No -- server is dedicated to stand-alone RapidMiner Server application only.

 

Hope this helps, the table ra_ent_dbconnectionentry seems to be the problem, but these might help you narrow down a few possibilities as to why it occured.

 

Eric

rfuentealba

Hi @Eric_Poitras,

 

That is indeed a problem. Were you able to run RapidMiner Server before? Because the thing is that, AFAIK, if the table ra_ent_dbconnectionentry is related with other tables, and if that one is lacking, you don't have a way to ensure that the rest of the tables don't have problems.

 

You might want to create it:

 

CREATE TABLE ra_ent_dbconnectionentry (

    id INT NOT NULL PRIMARY KEY AUTO_INCREMENT,

    databaseschema CHARACTER VARYING (255),

    host CHARACTER VARYING (255),

    name CHARACTER VARYING (255),

    passwd CHARACTER VARYING (255),

    port CHARACTER VARYING (255),

    system CHARACTER VARYING (255),

    usrname CHARACTER VARYING (255),

    propertiesmap_id INT NOT NULL

);

 

However, I think it should be better to create a new user and a new database on the MySQL server, stop RapidMiner Server, modify the standalone/configuration/standalone.xml file to point to the new MySQL database, and recreate it.

 

If you already have information on your RapidMiner Server database, you might want to retrieve the schema from both installations using MySQL and compare it. This might not be a graceful task, but it depends on whether RapidMiner Server has worked before and someone deleted that table or it hasn't worked at all.