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Io exception: The Network Adapter could not establish the connection

Hi experts,

Please help me on the following strange problem. Thanks in advance!
My JSP Web application runs on Weblogic server (ver 8.3.1), uses Oracle 9i DB. It's main process is
- Step 1: Upload an excel file with more 11 thousands of data row in only one sheet
- Step 2: Read above excel file
- Step 3: With each row:
    + Parse it to build an appropriate object
    + Open a connection to DB
    + Call a stored function in DB to write parsed object to a table in DB
    + Close connection

I'm testing this application in two cases.
    Case 1: Running on Sever A, installed on machine A, using DB installed on machine B
    Case 2: Running on Sever B, installed on machine B, using DB installed on machine B
With Case 1, everything's OK but with Case 2, it throws SQLException 'Io exception: The Network Adapter could not establish the connection' at row 3938 (8 times per 10 times of testing).
So strange that it thows that error at rows below: (one case of testing)
- from 3938 to 5709
- from 6609 to 6633
- from 10937 to 11138

Please help.
Thanks again!
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1 Solution
Murali MurugesanFull stack Java developerCommented:
initially try loading the excel file with just 4000 records and see if the same exception arises at line 3938 to 4000.

Is your server running in Cluster environment?.

Murali MurugesanFull stack Java developerCommented:
i would also suggest you to increase the number of connections in your connection pool before you test on Server B. This is more of a Network error rather than a db error.

ncsvietnamAuthor Commented:
@MuraliKanth: I've tried with 4000, even 3938 records, and it raised the same exception
And I think it's not DB error too.
Please tell me how to increase the number of connections in connection pool. I'm sorry because I'm new to DB management.

Open-Close connection and Re-Open too many times is my problem?
Murali MurugesanFull stack Java developerCommented:
You need to go to weblogic Administrator console. Under Connection pools you need to set the number for Maximum Capacity.

I would suggest a quick way to find out wherever your connection hangs. If you can deploy ur app to tomcat there is a connection log trace by setting like this  in server.xml

    <Context path="/proj" docBase="proj" debug="1" reloadable="true">
          <Resource name="<jdbc name>" auth="Container" type="javax.sql.DataSource" driverClassName="oracle.jdbc.driver.OracleDriver"
            url="jdbcurl" username="<username>" password="<pwd>" maxActive="4" maxIdle="2" maxWait="-1"
            logAbandoned="true"  removeAbandoned="true"  removeAbandonedTimeout="60"/>

So the highlighted ones will pointout the exact place where ur connection gets locked.

refer this for connection pool increase  http://edocs.bea.com/wls/docs61/jdbc/programming.html

ncsvietnamAuthor Commented:
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