Howto - connection load balancing

Question

Hello
I have a 11.1.0.7 clustered oracle db with two nodes. Using the oci access through the ojdbc14.jar for oracle 9.2.0.1 I programmed a datasource like this:
public class DataSource_9i_oci
extends OracleOCIConnectionPool
public DataSource_9i_oci() throws SQLException
super();
setUser(RACBehaviourTest.UNAME);
setPassword(RACBehaviourTest.PSWD);
setURL("jdbc:oracle:oci:@tnsname");
Properties poolConfig = new java.util.Properties( );
poolConfig.put (OracleOCIConnectionPool.CONNPOOL_MIN_LIMIT, "1");
poolConfig.put (OracleOCIConnectionPool.CONNPOOL_MAX_LIMIT, "100");
poolConfig.put (OracleOCIConnectionPool.CONNPOOL_INCREMENT, "2");
setPoolConfig(poolConfig);
My TNSNAMES.ORA contains the name
tnsname=
(description=
(load_balance=on)
(failover=on)
(address_list=
(address=(protocol=tcp)(host=xxx.xx.xx.xxx)(port=1521))
(address=(protocol=tcp)(host=xxx.xx.xx.xxx)(port=1521)))
(connect_data=
(service_name=service.name)
(failover_mode =
(type = select)
(method = basic))))
Then I spawned a group of threads each issuing a select statement and holding after that, until a central thread collects session statisticss from gv$session about the opened sessions in each instance for my user, and unblocks the working threads only after that.
This test is aimed at evaluating the load balancing capabilities of the oci vs thin drivers in different versions. The code above is the data source being used with the 9.2.0.1 oci driver.
Then I have another DataSource to be used in the same test and the ojdbc6.jar thin driver for 11.1.0.7. It is programmed like this:
public class DataSource_11g_thin
extends OracleDataSource
public DataSource_11g_thin(boolean enableFCF) throws SQLException
super();
String url = "jdbc:oracle:thin:@(DESCRIPTION=(LOAD_BALANCE=on) " +
"(ADDRESS=(PROTOCOL=TCP)(HOST=xxx.xx.xx.xxx) (PORT=1521)) " +
"(ADDRESS=(PROTOCOL=TCP)(HOST=xxx.xx.xx.xxx) (PORT=1521)) " +
"(CONNECT_DATA=(SERVICE_NAME=service.name)))";
setURL(url);
setUser(RACBehaviourTest.UNAME);
setPassword(RACBehaviourTest.PSWD);
setImplicitCachingEnabled(true);
Properties props = new Properties();
props.setProperty("InitialLimit", "500");
props.setProperty("MaxLimit", "500");
props.setProperty("ValidateConnection", "true");
setConnectionCacheProperties(props);
This test is using connection load balancing without leveraging the FAN infrastructure.
So, with this setup and creating 100 threads, what my tests show is that there's no load balancing in the 9i oci driver, all the 100 sessions are being opened in the same instance. The 11g thin driver however, distributes the opened sessions between the two nodes, even if in an unbalanced way (70-30).
Is there any way to activate load balancing in the oci driver ? Am I missing something ?
Thank you in advance.

Answer 1

use this link
http://www.trivadis.com/uploads/tx_cabagdownloadarea/J2EE_RAC_setup_xp_ok_01.pdf