Forum: Installation

Post: mathematica connection failure - "Error:Could not initialize class org.voltcore.utils"

mathematica connection failure - "Error:Could not initialize class org.voltcore.utils"
jcm
Jun 21, 2013
running ubuntu 12.04, pentium i7, 64 gb ram, 2tb hd

downloaded volt and successfully installed, initiated and tested 'voters' database example, sqlcmd, sqladmin.

Mathematica 9.0.1 is installed on the same machine and will connect, at least for now, on localhost

sucessfully added voltdbclient-3.3.0.1.jar to the Mathematica class path:
"/usr/local/Wolfram/Mathematica/9.0.1/SystemFiles/Links/DatabaseLink/\
Java/voltdbclient-3.3.0.1.jar"

sucessfully installed the driver :
JDBCDriver["Name" -> "volt", "Description" -> "",
"Driver" -> "org.voltdb.jdbc.Driver", "Protocol" -> "jdbc:voltdb://",
"Version" -> 2.,
"Location" -> "/home/pg/.Mathematica/DatabaseResources/volt.m"]

connecting to volt 'voter' databse example as localhost:21212 at the test I get
"Error:Could not initialize class org.voltcore.utils"

What does this mean and how do I fix it?
Thanks in advance. Jonathan Miller
bballard
Jun 21, 2013
Hi Jonathan,

You need to add guava-12.0.jar from the voltdb/lib directory to your classpath.

If that doesn't resolve the issue, check if Mathematica has an error log, there should be a stack trace somewhere that will provide more information on what the error might be.

Thanks,
Ben
tks
jcm
Jun 21, 2013
Hey Ben,

I'll add it to their class path and give it a try. If that doesn't work we'll find the log. Hopefully guava will work. I'll let you know.

Thank you so much for the quick reply.

Jonathan
jcm
Jun 21, 2013
Hi Ben,

Added guava. Now it's complaining "JDBC::error: "Could not initialize class org.voltcore.utils.DBBPool"
jcm
Jun 21, 2013
Ben,

I see that if I set up a new database connection to sya 'voter' using their wizard that if I set up at a system level I get more connection properties:
a checkbox for 'use a connection pool'
a dropdown to select a transaction isolation level (read uncommitted,read committed,repeatable read, serializable)
then a dialog to add or delete specific properties

do any of these pertain?

tks
bballard
Jun 21, 2013
Hi Jonathan,

If you have the option of connection pool vs. no connection pool, I would try no connection pool. I'm not sure if that could cause a problem, but I think no pool would be simpler to start.

For the transaction isolation level, the only one we support is serializable (which is the highest level anyway), so choose that option. I know if you try to set that to another option it will throw an exception.

Thanks,
Ben
jcm
Jun 21, 2013
Hi Ben,

It's still throwing the DBBpool exception.

I've been working with Wolfram and they may download volt next week and see if they can get the driver working.
I've been doing this since six this morning, so I'm done for today.
Tomorrow I'll start from scratch and see what happens.
Meantime let me know if the DBBpool exception means anything.

Thank you again for your help,

Jonathan
Shanky
Sep 26, 2013
Hi jcm,

Can you please share if DBBpool problem is solved.
If it is solved what is the solution to this problem.

Regards,
Shanky Goyal