Hi Srinivas,
exception "com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: 
Communications link failure" is very generic and basically means that there was 
something wrong with connecting to the MySQL. Could you share your entire 
execution log that was generated with --verbose flag?

Blindly shooting - it's suspicious that your issue appears only when certain 
amount of jobs is generated. MySQL is allowing limiting maximal number of 
concurrent connections. I would recommend checking defined connection limit on 
MySQL side (by SQL query show variables like "max_connections";) and compare it 
to number of created map tasks. In case that configured maximal value for 
connections is lower, then you need to either reconfigure mysql or sqoop (for 
example limit number of used mappers with --num-mappers argument or do not 
import all tables at once).

Jarcec

On Sat, May 26, 2012 at 09:40:47AM -0400, Srinivas wrote:
> 
> > I have couple of problems that I am running into:
> > 
> >     1. I was able to initiate only 5 sqoop jobs parallel which is = number 
> > of datanode's. 
> >     2. If i try to invoke more jobs parallel then only 5 jobs are picked by 
> > and the rest of them throwing an error saying 
> > "com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications 
> > link failure"
> > 
> >     Do you have any idea why this is happening.
> > 
> > Also, I have made sure that the mysql allows parallel connections from 
> > datanode's.
> > 
> > 
> > 

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