Communication link failure

[sukumar madawat]

Hi,
I am working with large data set. I have created 100 tables. each table has same schema (12 columns) and 10,000 rows.
There are 50 threads on each table that fires select * from table query .


I am using streaming resultset. i am closing connections, statements and resultset after using it. after running 40 - 50 min. it throws the exception:

com.mysql.jdbc.CommunicationsException: Communications link failure

Last packet sent to the server was 2217953 ms ago.
at com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:1070)
at com.mysql.jdbc.MysqlIO.reuseAndReadPacket(MysqlIO.java:2985)
at com.mysql.jdbc.MysqlIO.reuseAndReadPacket(MysqlIO.java:2871)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3414)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:910)
at com.mysql.jdbc.MysqlIO.nextRow(MysqlIO.java:1405)
at com.mysql.jdbc.RowDataDynamic.nextRecord(RowDataDynamic.java:413)
at com.mysql.jdbc.RowDataDynamic.next(RowDataDynamic.java:392)
at com.mysql.jdbc.ResultSetImpl.next(ResultSetImpl.java:7034)
at org.apache.commons.dbcp.DelegatingResultSet.next(DelegatingResultSet.java:169)

Caused by: java.net.SocketException: Connection reset
at java.net.SocketInputStream.read(SocketInputStream.java:168)
at com.mysql.jdbc.util.ReadAheadInputStream.fill(ReadAheadInputStream.java:113)
at com.mysql.jdbc.util.ReadAheadInputStream.readFromUnderlyingStreamIfNecessary(ReadAheadInputStream.java:160)
at com.mysql.jdbc.util.ReadAheadInputStream.read(ReadAheadInputStream.java:188)
at com.mysql.jdbc.MysqlIO.readFully(MysqlIO.java:2428)
at com.mysql.jdbc.MysqlIO.reuseAndReadPacket(MysqlIO.java:2938)
... 11 more

The same code works fine for lesser no of tables and threads.

i have set multiple timeout in my.ini file.

connect_timeout = 31536000
interactive_timeout = 31536000
wait_timeout = 31536000
net_write_timeout = 31536000

If anybody have any idea about it. Please guide me.
Thanks
Sukumar