Hi Amandeep,
Thanks for your info. My own java application has its own classes
and runs separately. The only thing is that it also tries to create hsql
server to cache some data. That's why I think there may be conflicts for
multiple hsql instances.
What I want to know about hadoop hsql is its server model (e.g.
In-Process (Standalone) Mode or Memory-Only Databases) and its default
configuration (like default url and database name). There are some
related properties in DBConfiguration class, like DRIVER_CLASS_PROPERTY
= "mapred.jdbc.driver.class" and URL_PROPERTY = "mapred.jdbc.url". But I
didn't find the default value for these properties.
Best wishes
Sincerely yours
Jianwu Wang
jia...@sdsc.edu
http://users.sdsc.edu/~jianwu/
Scientific Workflow Automation Technologies (SWAT) Laboratory
San Diego Supercomputer Center
University of California, San Diego
San Diego, CA, U.S.A.
Amandeep Khurana wrote:
What do you mean by your own java application? What are you trying to run?
Is it a Map Reduce job?
Secondly, hadoop talks to a database only when you are trying to read/write
data during a job... There is nothing else that it does.
The connectors to interface with databases are DBInputFormat and
DBOutputFormat.
-ak
Amandeep Khurana
Computer Science Graduate Student
University of California, Santa Cruz
On Tue, Sep 29, 2009 at 4:58 PM, Jianwu Wang <jia...@sdsc.edu> wrote:
Hi there,
When I have hadoop running (version 0.20.0, Pseudo-Distributed Mode), I
can not start my own java application. The exception complains that
'java.sql.SQLException: failed to connect to url
"jdbc:hsqldb:hsql://localhost/hsqldb". I have to stop hadoop to start my own
java application. Both my application and hadoop use hsqldb. Does anyone
know why and can help me out of this problem? Or tell me where to look for
hadoop hsqldb connection implementation, like which kind of hsql server mode
is used in hadoop and what is the default url of hsqldb for hadoop? I looked
into org.apache.hadoop.mapred.lib.db package but didn't find any clue.
Thanks in advance!
--
Best wishes
Sincerely yours
Jianwu Wang
jia...@sdsc.edu
