Connection Pooling in 903

Question

Hi,
I'm trying to use the oc4j connection pooling as described in the J2EE Service guide.
my data-sources.xml looks like this:
<?xml version="1.0" standalone='yes'?>
<!DOCTYPE data-sources PUBLIC "Orion data-sources" "http://xmlns.oracle.com/ias/dtds/data-sources.dtd">
<data-sources>
<data-source
class="com.evermind.sql.DriverManagerDataSource"
name="jCROSS"
location="jdbc/JCROSSCoreDS"
xa-location="jdbc/xa/JCROSSXADS"
ejb-location="jdbc/jCROSS"
pooled-location="jdbc/jCROSSPool"
max-connections="30"
min-connections="10"
connection-driver="oracle.jdbc.driver.OracleDriver"
username="username"
password="password"
url="jdbc:oracle:thin:@localhost:1521:test"
inactivity-timeout="30"
connection-retry-interval="1"
/>
</data-sources>
I'm running the following code:
Connection con[] = new Connection[15];
DataSource ds = null;
try {
InitialContext ctx = new InitialContext();
ds = (DataSource)ctx.lookup("jdbc/jCROSS");
for(int i=0;i<=10;i++)
con[i] = ds.getConnection();
} catch (Exception e) {
System.out.println(e);
} finally {
for(int i=0;i<=10;i++)
con.close();
I'm targeting the ejb-location because I need a pooled and transaction aware connection but when running this code with oc4j in debug mode I don't see that the connections are pooled:
Oracle9iAS (9.0.3.0.0) Containers for J2EE initialized
new DebugConnection(1)
new DebugConnection(2)
new DebugConnection(3)
Press enter to continue
new DebugConnection(4)
new DebugConnection(5)
new DebugConnection(6)
new DebugConnection(7)
new DebugConnection(8)
new DebugConnection(9)
new DebugConnection(10)
new DebugConnection(11)
closing DebugConnection(1)
closing DebugConnection(2)
closing DebugConnection(3)
closing DebugConnection(4)
closing DebugConnection(5)
closing DebugConnection(6)
closing DebugConnection(7)
closing DebugConnection(8)
closing DebugConnection(9)
closing DebugConnection(10)
closing DebugConnection(11)
Open sets: {}
Open connections: {}
Dirty connections:
Press enter to continue
when changing the lookup to :
ds = (DataSource)ctx.lookup("jdbc/jCROSSPool");
the pool works, but few questions arise from this behaviour:
1. Does the ejb-location support pooled connections? How? (in various articles it is recommend to specifically use this location).
2. Are the connections from the pooled-location transaction-aware?
Thx in advance.

Answer 1

Hi people!
I have a question on the above code.
I tried it myself on OC4j 9.0.3 (the one that comes with JDeveloper) and I noticed the connections on the pool. The problem is the behaviour of this code when the datasource is configured to have as a "max_connections" attribute a value less than 10, e.g. 8.
I tried a datasource of the following form
     <data-source
          class="com.evermind.sql.DriverManagerDataSource"
          name="OracleDS"
          location="jdbc/OracleCoreDS"
          xa-location="jdbc/xa/OracleXADS"
          ejb-location="jdbc/OracleDS"
          connection-driver="oracle.jdbc.driver.OracleDriver"
          username="myuser"
          password="mypass"
          min-connections="2"
          max-connections="8"
          url="jdbc:oracle:thin:@localhost:1521:orcl"
          inactivity-timeout="60">
     <property name="cacheScheme" value="DYNAMIC_SCHEME"/>
     </data-source>
but the execution of the code stops when it comes to get a Statement object out of the 9th connection object. Isn't the pool supposed to give a new connection and remove it when it's finished with it? After all, the documentation says that this is the default behaviour of the pool (it is not necessary to declare the DYNAMIC_SCHEME in the data-source.xml)
I am interested in this, because I have a bunch of JSP files (100 of them or even more) that shall use the same connection pool. If some of them are being executed concurrently, then there will definitely be a problem with the available connection objects.
Thanx