Sharing connection pooling ?

Is there a way to checkin the connection back to the pool and still have an access to the resultset in order to reuse the connection for other queries ?

gnosis,
You asked:
Is there a way to checkin the connection back to the pool and still have
access to the resultset in order to reuse the connection for other queries ?
A single "Connection" object can be used to create (theoretically) an infinite number of "Statement" objects where each "Statement" has an associated "ResultSet".
In other words, you don't need to release the "Connection" object in order to use it to perform a second query.
You are asking the classic wrong question.
Instead of asking, "How do I implement my proposed solution?", you should ask, "What is the best solution to my problem?"
Your problem is that you want to have two (or more) "ResultSet"s opened simultaneously and you think the only way to do that is to release the "Connection", hence your question.
A better question would be: "Can I have two 'ResultSet' objects opened simultaneously, using the same 'Connection'?"
Now, why do you think you need two "ResultSet" objects opened simultaneously?
Good Luck,
Avi.

Similar Messages

Shared Connection Pool via Singleton

I have just started to learn Java (more jsp & servlets) and have been going through "Core Servlets and Java Server Pages" and in there is stuff on connection pooling. The author provides a good a connection pool servlet that can be shared, but as I'm new and don't fully understand how everything works (got a basic idea).
How do i go about making the following code accessiable via a singleton class?
ConnectionPool Class
package sco;
import java.sql.*;
import java.util.*;
/** A class for preallocating, recycling, and managing
* JDBC connections.
* <P>
* Taken from Core Servlets and JavaServer Pages
* from Prentice Hall and Sun Microsystems Press,
* http://www.coreservlets.com/.
* © 2000 Marty Hall; may be freely used or adapted.
public class ConnectionPool implements Runnable {
private String driver, url, username, password;
private int maxConnections;
private boolean waitIfBusy;
private Vector availableConnections, busyConnections;
private boolean connectionPending = false;
public ConnectionPool(String driver, String url,
                        String username, String password,
                        int initialConnections,
                        int maxConnections,
                        boolean waitIfBusy)
      throws SQLException {
    this.driver = driver;
    this.url = url;
    this.username = username;
    this.password = password;
    this.maxConnections = maxConnections;
    this.waitIfBusy = waitIfBusy;
    if (initialConnections > maxConnections) {
      initialConnections = maxConnections;
    availableConnections = new Vector(initialConnections);
    busyConnections = new Vector();
    for(int i=0; i<initialConnections; i++) {
      availableConnections.addElement(makeNewConnection());
public synchronized Connection getConnection()
      throws SQLException {
    if (!availableConnections.isEmpty()) {
      Connection existingConnection =
        (Connection)availableConnections.lastElement();
      int lastIndex = availableConnections.size() - 1;
      availableConnections.removeElementAt(lastIndex);
      // If connection on available list is closed (e.g.,
      // it timed out), then remove it from available list
      // and repeat the process of obtaining a connection.
      // Also wake up threads that were waiting for a
      // connection because maxConnection limit was reached.
      if (existingConnection.isClosed()) {
        notifyAll(); // Freed up a spot for anybody waiting
        return(getConnection());
      } else {
        busyConnections.addElement(existingConnection);
        return(existingConnection);
    } else {
      // Three possible cases:
      // 1) You haven't reached maxConnections limit. So
      //    establish one in the background if there isn't
      //    already one pending, then wait for
      //    the next available connection (whether or not
      //    it was the newly established one).
      // 2) You reached maxConnections limit and waitIfBusy
      //    flag is false. Throw SQLException in such a case.
      // 3) You reached maxConnections limit and waitIfBusy
      //    flag is true. Then do the same thing as in second
      //    part of step 1: wait for next available connection.
      if ((totalConnections() < maxConnections) &&
          !connectionPending) {
        makeBackgroundConnection();
      } else if (!waitIfBusy) {
        throw new SQLException("Connection limit reached");
      // Wait for either a new connection to be established
      // (if you called makeBackgroundConnection) or for
      // an existing connection to be freed up.
      try {
        wait();
      } catch(InterruptedException ie) {}
      // Someone freed up a connection, so try again.
      return(getConnection());
// You can't just make a new connection in the foreground
// when none are available, since this can take several
// seconds with a slow network connection. Instead,
// start a thread that establishes a new connection,
// then wait. You get woken up either when the new connection
// is established or if someone finishes with an existing
// connection.
private void makeBackgroundConnection() {
    connectionPending = true;
    try {
      Thread connectThread = new Thread(this);
      connectThread.start();
    } catch(OutOfMemoryError oome) {
      // Give up on new connection
public void run() {
    try {
      Connection connection = makeNewConnection();
      synchronized(this) {
        availableConnections.addElement(connection);
        connectionPending = false;
        notifyAll();
    } catch(Exception e) { // SQLException or OutOfMemory
      // Give up on new connection and wait for existing one
      // to free up.
// This explicitly makes a new connection. Called in
// the foreground when initializing the ConnectionPool,
// and called in the background when running.
private Connection makeNewConnection()
      throws SQLException {
    try {
      // Load database driver if not already loaded
      Class.forName(driver);
      // Establish network connection to database
      Connection connection =
        DriverManager.getConnection(url, username, password);
      return(connection);
    } catch(ClassNotFoundException cnfe) {
      // Simplify try/catch blocks of people using this by
      // throwing only one exception type.
      throw new SQLException("Can't find class for driver: " +
                             driver);
public synchronized void free(Connection connection) {
    busyConnections.removeElement(connection);
    availableConnections.addElement(connection);
    // Wake up threads that are waiting for a connection
    notifyAll();
public synchronized int totalConnections() {
    return(availableConnections.size() +
           busyConnections.size());
/** Close all the connections. Use with caution:
   * be sure no connections are in use before
   * calling. Note that you are not <I>required</I> to
   * call this when done with a ConnectionPool, since
   * connections are guaranteed to be closed when
   * garbage collected. But this method gives more control
   * regarding when the connections are closed.
public synchronized void closeAllConnections() {
    closeConnections(availableConnections);
    availableConnections = new Vector();
    closeConnections(busyConnections);
    busyConnections = new Vector();
private void closeConnections(Vector connections) {
    try {
      for(int i=0; i<connections.size(); i++) {
        Connection connection =
          (Connection)connections.elementAt(i);
        if (!connection.isClosed()) {
          connection.close();
    } catch(SQLException sqle) {
      // Ignore errors; garbage collect anyhow
public synchronized String toString() {
    String info =
      "ConnectionPool(" + url + "," + username + ")\n" +
      ", available=" + availableConnections.size() + "\n" +
      ", busy=" + busyConnections.size() + "\n" +
      ", max=" + maxConnections;
    return(info);
ScoPool Class (singleton to access the connection pool)
package sco;
public class ScoPool extends ConnectionPool {
private ScoPool pool = null;
private ScoPool() {
    super(); // Call parent constructor
public static synchronized ScoPool getInstance() {
    if(pool == null) {
      pool = new ScoPool();
    return(pool);
}Please help a newbie.

Figured it out.
package sco;
import java.sql.SQLException;
public class ScoPool extends ConnectionPool {
private static ScoPool pool;
private ScoPool(String driver, String url, String username, String password,
                  int initialConnections, int maxConnections, boolean waitIfBusy) throws SQLException {
    super(driver, url, username, password, initialConnections, maxConnections, waitIfBusy); // Call parent constructor
public static synchronized ScoPool getInstance() {
    if(pool == null) {
      String driver = "com.microsoft.jdbc.sqlserver.SQLServerDriver";
      String url = "jdbc:microsoft:sqlserver://MIM-W0432:1433;DatabaseName=sco";
      String username = "sco_user";
      String password = "123";
      int initCon = 5;
      int maxCon = 10;
      boolean waitIfBusy = true;
      try {
        pool = new ScoPool(driver, url, username, password, initCon, maxCon, waitIfBusy);
      catch(SQLException sqle) {
    return pool;
}

How to kill a Query In Shared Connection Pool

Is it possible to kill just a single "long running query" (and in this case after 5 seconds) when the connection is through a connection pool?
Environment is Exadata, about a 1500 Users making search query and may do a query for "THE%"
Is there a profile setting?
Regards

This sounds like a perfect case for the Resource Manager, with which Exadata is very closely integrated. Here is an example,
http://www.orafaq.com/forum/mv/msg/121801/333625/0/#msg_333625

Is connection pooling and sharing available on Oracle 9i RDBMS ?

Hello,
I would like to connect from oracle to sql server through db link and ODBC (Heterogenous connectivity). But every session in oracle launch session in sql server. Is it possible to have connection pooling and sharing from Oracle RDBMS level ? I need one solution : when (for example) i run 100 sessions in Oracle i would like to see 10 sessions on sql server. I would like remain 90 sessions from oracle to be queued.
I would mention that i was using Heterogenous connectivity with multithreading agent (agtctl) without success.
appreciate any help :-)

There are two concepts you could evaluate, but they are mainly used for connections to the database, not to sqlserver, but if you can make them work with heterogeneous connectivity this could help:
Connection Pooling. When many sessions are connecting to the same database, it could be that some of them remain idle. Oracle can detect them and timed them out letting another session to enter into the database, letting the idle session remain open without closing its session. This is configured by means of the shared server architecture.
Session Multiplexing. Session multiplexing allows the same bandwidth to be used by many sessions at the same time, this enables the server to use fewer network connection endpoints for incoming request. In order for you to configure session multiplexing you have to configure connection manager.
Ref. Oracle® Database Net Services Administrator's Guide
10g Release 2 (10.2)
Part Number B14212-02
~ Madrid
http://hrivera99.blogspot.com/

Proxy functionality in the database connection pool

Hi,
I am scouring the internet and forums looking for a way to connect to my database from the .rpd connection pool using proxy authetication. NOT Act-As proxy that is a BIEE feature, but RDBMS proxy authentication with BIEE acting as the middle-tier connecting on behalf of many users and authenticating to the RDBMS AS THE INDIVIDUAL USER. I haven't had any luck, and am hoping someone here has set up this same kind of access.
We have a requirement to use SSO with BIEE to integrate with our portal and discoverer apps. We also have a requirement to use EUS (Enterprise User Security). EUS allows you to login to the database using the userids/password from OID. Note that the database doesn't support the SSO token, but it uses the same userid/password stored in OID for authenticating to the database. You still must initiate a connection to the database, but the authentication goes to LDAP. Every connection to BIEE may be using a different userid - we will not have a shared login.
So the issue I see is:
- We configure SSO
- In the BI Server the :USER session variable is set (but NOT :PASSWORD, since BI Server didn't authenticate you it doesn't have the password)
- We create a connection pool - This is where we hit the issue - we need each connection to BI Server to connect down to the database as the SSO user. Since we aren't using a shared account we can't enter a userid/password in this connection. We also can't user :USER and :PASSWORD since SSO doesn't set the :PASSWORD session variable. What I would hope to find is a checkbox "Proxy Authentication" (around where "Shared Logon" checkbox is located) that would connect to the database as the proxy user and then switch to the SSO user.
This is what happens with BI Publisher. On the JDBC connection screen there is a "Proxy Authentication" checkbox.
So, has anyone already solved this problem? Thanks!

Hello, is there anyone knows what this program does
and how this program is executed? There is nodatabase
mentioned.That's because it's expecting the URL (which contains
the database type, hostname, and so on) to be passed
in on the command line (argv[0]), as well as the
username and password (argv[1] and argv[2]).
Thank you very much for your help.
Regards,
Lucas

Resource Management of Shared Resource Pool at the Project Level

I am having difficulty figuring out how to implement our resource management process. Currently we have one "Resource Pool" project that has all the shared resources. It is connected to both a "master portfolio" plan that has some task
detail in it and other individual project plans that have their own WBS (for larger projects).
The difficulty arises because we want to do resource allocation at a project level, but the resource usage view shows the WBS/task level detail. I've tried grouping the resources assignments by resource and then project, but since everything is
in the "Resource Pool" project, they all group under that project. I've tried adding the "Project" field and it does show as the source project, but it doesn't group on that field, but rather the "Resource Pool" project
only.
How can I see resource allocation/usage at just the project level so our managers can do planning, negotiation, and re-allocation on a periodic basis with one simple view?
My best current idea is to disconnect all the sub-tasks from the sharer, eliminate the WBS below the project level in the master plan and attach resources at that single line project in that master plan. Then, we would have to manually alter the "Max"
available time in the individual sub-plans as we altered allocations. That essentially disconnects individual plans from both the master plan and the shared resource pool.
Is there a better way?

Mark,
Yeah, I think there is a better way. Having a linked structure the contains both a pool file and a dynamic master is tenuous enough (i.e. prone to corruption), but if you start disconnecting from the pool and and messing with the master, you will most certainly
invite trouble.
But here is an approach that might work. I tested it on a sample pool file with two sharer files and I think it might give you what you want.
1. First, either manually copy or use VBA to copy the contents of the Project field to a custom text field in each sharer file
2. In the pool file display the Resource Usage view
3. Create a group that first groups on the Resource Name and then on the Text1 field, and select "group assignments, not resource"
4. Change the Text1 group field to be "assignment"
Does that give you what you want?
To help visualize, here is a screenshot of my test file. After grouping I applied a filter to Text1 with the option to also show summary tasks:
John

Has anyone run the connection pooling for mysql & tomcat successfully?

I'm trying to set up connection pooling. I'm following the how-to page at
http://jakarta.apache.org/tomcat/tomcat-4.1-doc/jndi-datasource-examples-howto.html
But when i test the DBTest/test.jsp file, tomcat displays an error =
could not load jdbc driver class 'null'(msdos)
i have placed all the required .jar files in the tomcat lib.
below is the cofiguration i did to the server.xml file



<Server port="8005" shutdown="SHUTDOWN" debug="0">

<Listener className="org.apache.catalina.mbeans.ServerLifecycleListener"
debug="0"/>
<Listener className="org.apache.catalina.mbeans.GlobalResourcesLifecycleListener"
debug="0"/>

<GlobalNamingResources>

<Environment name="simpleValue" type="java.lang.Integer" value="30"/>

<Resource name="UserDatabase" auth="Container"
type="org.apache.catalina.UserDatabase"
description="User database that can be updated and saved">
</Resource>
<ResourceParams name="UserDatabase">
<parameter>
<name>factory</name>
<value>org.apache.catalina.users.MemoryUserDatabaseFactory</value>
</parameter>
<parameter>
<name>pathname</name>
<value>conf/tomcat-users.xml</value>
</parameter>
</ResourceParams>
</GlobalNamingResources>


<Service name="Tomcat-Standalone">


<Connector className="org.apache.coyote.tomcat4.CoyoteConnector"
port="8080" minProcessors="5" maxProcessors="75"
enableLookups="true" redirectPort="8443"
acceptCount="100" debug="0" connectionTimeout="20000"
useURIValidationHack="false" disableUploadTimeout="true" />




<Connector className="org.apache.coyote.tomcat4.CoyoteConnector"
port="8009" minProcessors="5" maxProcessors="75"
enableLookups="true" redirectPort="8443"
acceptCount="10" debug="0" connectionTimeout="20000"
useURIValidationHack="false"
protocolHandlerClassName="org.apache.jk.server.JkCoyoteHandler"/>











<Engine name="Standalone" defaultHost="localhost" debug="0">



<Logger className="org.apache.catalina.logger.FileLogger"
prefix="catalina_log." suffix=".txt"
timestamp="true"/>


<Realm className="org.apache.catalina.realm.UserDatabaseRealm"
debug="0" resourceName="UserDatabase"/>







<Host name="localhost" debug="0" appBase="webapps"
unpackWARs="true" autoDeploy="true">
<Context path="/my-jsp" docBase="c:\JSP-Files" debug="0"
privileged="true" reloadable="true" />
     <Context path="" docBase="c:\Inetpub\wwwroot" debug="0" privileged="true" />
<Context path="/sharon" docBase="C:\Tomcat 4.1\webapps\sharon" debug="0" privileged="true" />





<Logger className="org.apache.catalina.logger.FileLogger"
directory="logs" prefix="localhost_log." suffix=".txt"
     timestamp="true"/>




<Context path="/examples" docBase="examples" debug="0"
reloadable="true" crossContext="true">
<Logger className="org.apache.catalina.logger.FileLogger"
prefix="localhost_DBTest_log." suffix=".txt"
timestamp="true"/>
<Ejb name="ejb/EmplRecord" type="Entity"
home="com.wombat.empl.EmployeeRecordHome"
remote="com.wombat.empl.EmployeeRecord"/>



          
<Environment name="maxExemptions" type="java.lang.Integer"
value="15"/>
<Parameter name="context.param.name" value="context.param.value"
override="false"/>
<Resource name="jdbc/EmployeeAppDb" auth="SERVLET"
type="javax.sql.DataSource"/>
<Resource name="jdbc/TestDB"
     auth="Container"
     type="javax.sql.DataSource"/>
<ResourceParams name="jdbc/TestDB">
<parameter>
     <name>factory</name>
     <value>org.apache.commons.dbcp.BasicDataSourceFactory</value>
     </parameter>
     
     <parameter>
     <name>maxActive</name>
     <value>100</value>
     </parameter>
     
     <parameter>
     <name>maxIdle</name>
     <value>30</value>
     </parameter>
     
     <parameter>
     <name>maxWait</name>
     <value>10000</value>
     </parameter>

<parameter>
<name>user</name>
<value>javauser</value>
</parameter>
<parameter>
<name>password</name>
<value>javadude</value>
</parameter>

<parameter>
<name>driverClassName</name>
<value>org.gjt.mm.mysql.Driver</value>
</parameter>

     <parameter>
     <name>url</name>
     <value>jdbc:mysql://localhost:3306/javatest?autoReconnect=true</value>
</parameter>
</ResourceParams>
<Resource name="mail/Session" auth="Container"
type="javax.mail.Session"/>
<ResourceParams name="mail/Session">
<parameter>
<name>mail.smtp.host</name>
<value>localhost</value>
</parameter>
</ResourceParams>
<ResourceLink name="linkToGlobalResource"
global="simpleValue"
type="java.lang.Integer"/>
</Context>
</Host>
</Engine>
</Service>



</Server>
Pleas4 help!!!

you have your driver jar in Tomcat\common\lib?
if so, check your classpath, it could be that.

ABAP MDM Connection Pool concept? Slow Performance in call

Hi,
I'm playing around with the MDM ABAP API, and I found the performance a bit disappointing.
I followed the guide "How To identify master data records using SAP MDM 5.5 ABAP API's" and wrote a test program.
The program makes a connection, triggers an MDM query, and disconnects.
    CREATE OBJECT api
      EXPORTING
        iv_log_object_name = logical_object_name.
    api->mo_accessor->connect( language ).
* Query parameters
    ls_query-parameter_code = 'Material_Number'.
    ls_query-operator = 'CS'.
    ls_query-dimension_type = 1.
    ls_query-constraint_type = 8.
    ls_value = '70'.
    GET REFERENCE OF ls_value INTO ls_query-value_low.
    APPEND ls_query TO lt_query.
    CLEAR ls_query.
* Search
    CALL METHOD api->mo_core_service->query
      EXPORTING
        iv_object_type_code = 'Products'
        it_query            = lt_query
        iv_hits_max         = 10
      IMPORTING
        et_result_set       = lt_result_set.
Connection is really fast (a split second)
First time triggered 'query' method took about 30-50 seconds.
Second time triggering 'query' method took a split second.
Further to my investigation, I found out the most expensive code lies in
CL_MDM_PROVIDER_SP04_PL03->IF_MDM_CORE_SERVICES~QUERY
*--- load field meta data ---*
IF mt_mdm_field_meta_data IS INITIAL
OR mt_field_meta_data     IS INITIAL.
    CALL METHOD me->_load_field_information.
ENDIF.
Within this method loadfield_information, it rips all the table and structure information
from MDM, and ALL language texts and so on.
It has many loops, and within the loops querying MDM for more information.
Is there anyway to speed this up?
Why aren't these data cached? (They don't change so often in a production environment)
I also found a shared memory class CL_MDM_METADATA_ACCESS but it is not used anywhere.
No shared memory area relevant is delivered by SAP as well.
Any ideas?
Cheers,
Michael.

Hi Michael,
you're welcome.
I'm not sure how the Connection Pooling to MDM is really done by the ABAP APIs as I'm unfortunately not an API developer but just use the API for my programms.
What I learned during this process is that the repository meta data (meaning table descriptions, and so on) have to be loaded at least once for each connection. This makes sense because a repository can always be changed manually by any user. And I don't think that it would be faster to hold the meta data persistent in the ABAP layer because then you would need to compare the ABAP available meta information with the current meta information of the repository. This could take even longer.
I've solved this "issue" in a way that I really rely on the connection because a single connection is very stable. So I call the "CONNECT" only once in the very beginning, run through my coding and the very last step is the "DISCONNECT". As long as a connection is available, the meta data is cached in the API layer (at least this is the case for SP05).
BR Michael

Oc4j connection pool: too much INACTIVE connections

I am publishing an application - developed using Eclipse and previously published in Tomcat (where it works perfectly for a long time) - within corporate servers using Oc4j version 10.1.3. The database server is Oracle 9g.
After the deployment operation, the application seems to work, but that happens during the work by users, there are still many connections whith status "INACTIVE", until to complete all the available connections.
The datasource is set as follows:
<connection-pool name="ConnectionPoolRichiestaPubblicazione">
<connection-factory factory-class="oracle.jdbc.pool.OracleDataSource"
user="REDAZIONE"
password="password"
url="jdbc:oracle:thin:@(DESCRIPTION=(FAILOVER=ON)
     (ADDRESS_LIST=(LOAD_BALANCE=ON)
     (ADDRESS=(PROTOCOL=TCP)
     (HOST=10.146.2.86)(PORT=1521))
     (ADDRESS=(PROTOCOL=TCP)(HOST=10.146.2.86)(PORT=1521)))
     (CONNECT_DATA=
(SERVER=DEDICATED)
(SERVICE_NAME=XE)
(FAILOVER_MODE=(TYPE=SELECT)(METHOD=BASIC)(RETRIES=180)(DELAY=5))))">
</connection-factory>
</connection-pool>
<managed-data-source
jndi-name="jdbc/RichiestaPubblicazioneDS"
name="RichiestaPubblicazioneDS"
connection-pool-name="ConnectionPoolRichiestaPubblicazione" />
The java code to establish a connection is as follows:
private Connection creaConnessioneDataSource(String nomedatasource) throws ConnessioneException{
          LOGGER.debug("START");
          try {
               InitialContext context = new InitialContext();
               DataSource ds = (DataSource)context.lookup(nomedatasource);
               LOGGER.debug("URL DATASOURCE : " + ds.getConnection().getMetaData().getURL());
               LOGGER.debug("USERNAME : " + ds.getConnection().getMetaData().getUserName());
               this.conn = ds.getConnection();
          catch( Exception e ) {
               LOGGER.error("Errore nella connessione tramite datasource : " + StringUtils.getCustomStackTrace(e));
          LOGGER.debug("END");
          return this.conn;
Connections and statements are closed using the following methods:
     public boolean chiudi(Connection conn){
          LOGGER.debug("START");
          boolean esito = false;
          if (conn != null){
               try {
                    conn.close();
                    esito = true;
                    LOGGER.debug("Connessione chiusa");
               catch (SQLException e) {
                    LOGGER.error("Eccezione nella chiusura della connessione : " + e);
          LOGGER.debug("END");
          return esito;
     public boolean chiudi(Statement stmt){
          LOGGER.debug("START");
          boolean esito = false;
          if (stmt != null){
               try {
                    stmt.close();
                    esito = true;
                    LOGGER.debug("Statement chiuso");
               } catch (SQLException e) {
                    LOGGER.error("Eccezione nella chiusura dello statement : " + e);
                    e.printStackTrace();
          LOGGER.debug("END");
          return esito;
Here are a couple of examples of code that interact with the database:
     public List<StatoRichiestaSintesi> getElencoStatiRichieste() throws ConnessioneException{
          LOGGER.debug("START");
          List<StatoRichiestaSintesi> listaStati=new LinkedList<StatoRichiestaSintesi>();
          LOGGER.debug("Apriamo connessione e statement");
          Connection conn = databaseManager.creaConnessioneDataSource(datasource);
          Statement stmt = databaseManager.creaStatement(conn, false);
          String sql="SELECT * FROM STATORICHIESTA";
          try {
               ResultSet rs = stmt.executeQuery(sql);
               while(rs.next()){
                    StatoRichiestaSintesi temp=new StatoRichiestaSintesi();
                    temp.setIdStato(rs.getString(1));
                    temp.setDescrizioneStato(rs.getString(2));
                    listaStati.add(temp);
               LOGGER.debug("Numero record trovati : " + listaStati.size());
          } catch (SQLException e) {
               LOGGER.error("Eccezione di tipo SQL : " + StringUtils.getCustomStackTrace(e));
          finally{
               LOGGER.debug("Chiusura di statement e connessione");
               databaseManager.chiudi(stmt);
               databaseManager.chiudi(conn);
          LOGGER.debug("END");
          return listaStati;
Below is another example using PreparedStatement:
     private synchronized void aggiungiIndicazioneProgetto(String idprogetto, String idrichiesta) {
          LOGGER.debug("START");
          LOGGER.debug("Creo un oggetto di tipo connessione");
          Connection conn = databaseManager.creaConnessioneDataSource(datasource);
          LOGGER.debug("Definisco una query sql");
          String sql = "INSERT INTO RICHIESTAPROGETTO (IDRICHIESTA,IDPROGETTO) VALUES (?,?)";
          LOGGER.debug("Dichiaro un oggetto di tipo preparedstatement");
          PreparedStatement stmt = null;
          try {
               LOGGER.debug("Istanzio l'oggetto statement");
               stmt = conn.prepareStatement(sql);
               LOGGER.debug("Imposto i segnalibri della query");
               stmt.setString(1, idrichiesta);
               stmt.setString(2, idprogetto);
               LOGGER.debug("Eseguo la query di inserimento del progetto");
               stmt.executeUpdate();
          } catch (SQLException e) {
               LOGGER.error("Eccezione di tipo SQL : " + StringUtils.getCustomStackTrace(e));
          finally {
               LOGGER.debug("Chiusura di statement e connessione");
               databaseManager.chiudi(stmt);
               databaseManager.chiudi(conn);
          LOGGER.debug("END");
     Which may be the cause for the described behavior?
     I hope someone help me..

My problem is the following.
If I deploy my application with the illustred datasource in my local OC4J (10.1.3 in a Standalone Environment) all work fine.
The application creates a reasonable number of connections (in ORACLE - 10g Enterprise Edition Release 10.2.0.4.0 - db I run the query verification "select count(*) from v$session where username='MYAPPLICATION'"), and overall performance is very good.
If, however, to deploy on the production machine of corporate (always 10.1.3, but obviously in Oracle Application Server Environment) the
number of connections (status 'INACTIVE') grows massively, and this is saturated in a short time.
The exception that at the end from the application is that:
java.sql.SQLException: ORA-01034: ORACLE not available
ORA-27101: shared memory realm does not exist
Linux Error: 2: No such file or directory
oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java:138)
oracle.jdbc.driver.T4CTTIoer.processError(T4CTTIoer.java:316)
oracle.jdbc.driver.T4CTTIoer.processError(T4CTTIoer.java:277)
oracle.jdbc.driver.T4CTTIoer.processError(T4CTTIoer.java:272)
oracle.jdbc.driver.T4CTTIoauthenticate.receiveOsesskey(T4CTTIoauthenticate.java:243)
oracle.jdbc.driver.T4CConnection.logon(T4CConnection.java:304)
oracle.jdbc.driver.PhysicalConnection.<init>(PhysicalConnection.java:430)
oracle.jdbc.driver.T4CConnection.<init>(T4CConnection.java:151)
oracle.jdbc.driver.T4CDriverExtension.getConnection(T4CDriverExtension.java:32)
oracle.jdbc.driver.OracleDriver.connect(OracleDriver.java:608)
oracle.jdbc.pool.OracleDataSource.getConnection(OracleDataSource.java:218)
oracle.jdbc.pool.OracleConnectionPoolDataSource.getPhysicalConnection(OracleConnectionPoolDataSource.java:114)
oracle.jdbc.pool.OracleConnectionPoolDataSource.getPooledConnection(OracleConnectionPoolDataSource.java:77)
oracle.jdbc.pool.OracleImplicitConnectionCache.makeCacheConnection(OracleImplicitConnectionCache.java:1361)
oracle.jdbc.pool.OracleImplicitConnectionCache.getCacheConnection(OracleImplicitConnectionCache.java:441)
oracle.jdbc.pool.OracleImplicitConnectionCache.getConnection(OracleImplicitConnectionCache.java:336)
oracle.jdbc.pool.OracleDataSource.getConnection(OracleDataSource.java:286)
oracle.jdbc.pool.OracleDataSource.getConnection(OracleDataSource.java:179)
oracle.jdbc.pool.OracleDataSource.getConnection(OracleDataSource.java:159)
oracle.oc4j.sql.DataSourceConnectionPoolDataSource.getPooledConnection(DataSourceConnectionPoolDataSource.java:57)
oracle.oc4j.sql.xa.EmulatedXADataSource.getXAConnection(EmulatedXADataSource.java:92)
oracle.oc4j.sql.spi.ManagedConnectionFactoryImpl.createXAConnection(ManagedConnectionFactoryImpl.java:211)
oracle.oc4j.sql.spi.ManagedConnectionFactoryImpl.createManagedConnection(ManagedConnectionFactoryImpl.java:170)
com.evermind.server.connector.ApplicationConnectionManager.createManagedConnection(ApplicationConnectionManager.java:1377)
oracle.j2ee.connector.ConnectionPoolImpl.createManagedConnectionFromFactory(ConnectionPoolImpl.java:327)
oracle.j2ee.connector.ConnectionPoolImpl.access$800(ConnectionPoolImpl.java:98)
also I add the other attributes of Connection Pool of the Datasource:
Connections:
Initial size of Connection Cache = 0
Minimum Number of Connections = 0
Maximum Number of Connections = -1
Connection Retry Interval (seconds) = 1
Maximum Connection Attempts = 3
Maximum Number of Statements Cached = 0
Lower Threshold Limit On Pool (%)= 20
Validate Connection = False
What I can do?
many thanks..

Urgent...Help Needed.1. Helper Class 2. Connection Pool

Hello,
1. There are few helper classes which has to be
shared b/w session and entity beans. But it
seems,state of the object is not transfered to entity
bean though the class has implemented Serializable
interface. I have archived all the helper class and
copied to j2ee\home\lib directory. The same jar file
is made accessible to server via updating <library-
path> in j2ee/home/config/application.xml file.
2. How can i utilise connection pooling in oc4j. In data-sources.xml, i am using
"OracleConnectionPoolDataSource" class. But i feel that connection pool is not utilised coz server hangs in the middle of the retrieval.
The value of max-connections is 50.
We are actually migrating from Weblogic 5.1.0 to Oracle 9i AS. In weblogic, we had given 10 max connections in weblogic.properties,it is working fine. But i dont understand why it is not working in 9i AS though the max-connections is 50.
Kindly let me know the solution at the earliest as it is very urgent to get the program running...
Thanx and Regards,
Achyuth

Hi,
hopefully I can help you.
1. There are few helper classes which has to be ...We have just the same constellation. We have put the HelperClasses in the
J2EE/home/lib dir, NOT specifying it in the application.xml. So everything works fine.
The only thing: never, again: never put these files within WEB-INF and the lib-dir.
With the HelperClasses in both we have only faced massive problems, mostly ClasCastExceptions.
We had once all the helperClasses within J2EE/home/applications/lib, but this requires to
specify this dir within the orion-application.xml within the appl dir in applications-deployment.
It also worked fine.
2. How can i utilise connection pooling in oc4j. In data-sources.xml, i am using ...I'm not sure of this, but I think, the container handles Connection Pooling, no matter what Factory you
specify. But I think, the Class hasn't to be OracleConnectionPool ... but I have to check this (right now
I have no access to our datasource.xml ..)
cu
ed

How to use connection pooling in jsp?

I'm new to world of JSP. I'm developing web application using Oracle 8i and JSP to implement it. I'm using jakarta-tomcat server for this purpose.
I'll frequently access the database. so I want to use the connection pooling.
Can anybody explain the simple procedure to use it
thanx

Hello syyuen,
Please help me, here iam sending u my server.xml , web.xml and servlet
application. I put classes12.jar in tomcat/common/lib. and above servlet
class application under tomcat/webapps/root/web-inf/classes
and this is a simple servlet program for getting connection from the
connection pool of tomcat using tyrex..
my oracle database name is "myuser" and password is "mypass"
either u check my server.xml or tell me where under which tag should i
place <Resource...> tag in server.xml and should i need to modify any
other places..??
server.xml
<Server port="8005" shutdown="SHUTDOWN" debug="0">
          
<Service name="Tomcat-Standalone">
     
<Connector className="org.apache.catalina.connector.http.HttpConnector"
port="8080" minProcessors="5" maxProcessors="75"
enableLookups="true" redirectPort="8443"
acceptCount="10" debug="0" connectionTimeout="60000"/>
          
<Connector className="org.apache.ajp.tomcat4.Ajp13Connector"
port="8009" minProcessors="5" maxProcessors="75"
acceptCount="10" debug="0"/>
          
<Engine name="Standalone" defaultHost="localhost" debug="0">
     
<Logger className="org.apache.catalina.logger.FileLogger"
prefix="catalina_log." suffix=".txt"
timestamp="true"/>
     
               
               
<Realm className="org.apache.catalina.realm.JDBCRealm" debug="99"
          driverName="oracle.jdbc.driver.OracleDriver"
               connectionURL="jdbc:oracle:thin:@oracle:1521:ORCL"
connectionName = "mail"
connectionPassword = "mail"
          userTable="users" userNameCol="user_name" userCredCol="user_pass"
               userRoleTable="user_roles" roleNameCol="role_name" />
                    
               
<Host name="localhost" debug="1" appBase="webapps" unpackWARs="true">
     <Valve className="org.apache.catalina.valves.AccessLogValve"
     directory="logs" prefix="localhost_access_log." suffix=".txt"
     pattern="common"/>
<Logger className="org.apache.catalina.logger.FileLogger"
directory="logs" prefix="localhost_log." suffix=".txt"
     timestamp="true"/>
               
               
               
<Context path="/manager" docBase="manager" debug="0" privileged="true"/>

     <Context path="/localhost" docBase="localhost" debug="0" reloadable="false" override="true">
          <Resource name="jdbc/myConnection" auth="SERVLET" type="javax.sql.DataSource"/>
          <ResourceParams name="jdbc/myConnection">
               <parameter><name>user</name><value>myuser</value></parameter>
               <parameter><name>password</name><value>mypass</value></parameter>
               <parameter><name>driverClassName</name><value>oracle.jdbc.driver.OracleDriver</value></parameter>
               <parameter>
                    <name>url</name>
                    <value>jdbc:oracle:thin:@oracle:1521:ORCL</value>
               </parameter>
               <parameter>
                    <name>maxActive</name>
                    <value>32</value>
               </parameter>
               <parameter>
                    <name>maxIdle</name>
                    <value>10</value>
               </parameter>
          </ResourceParams>




</Context>
</Host>
</Engine>
</Service>
     
<Service name="Tomcat-Apache">
<Connector className="org.apache.catalina.connector.warp.WarpConnector"
port="8008" minProcessors="5" maxProcessors="75"
enableLookups="true" appBase="webapps"
acceptCount="10" debug="0"/>
               
<Engine className="org.apache.catalina.connector.warp.WarpEngine"
name="Apache" debug="0">
               
<Logger className="org.apache.catalina.logger.FileLogger"
prefix="apache_log." suffix=".txt"
timestamp="true"/>
               
<Realm className="org.apache.catalina.realm.MemoryRealm" />
</Engine>
</Service>
</Server>
web.xml
<web-app>
<servlet>
<servlet-name>conServlet</servlet-name>
<servlet-class>conServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>conServlet</servlet-name>
<url-pattern> /conServlet </url-pattern>
</servlet-mapping>
<resource-ref>
<description> Resource reference to java.sql.Connection
factory defined in server.xml
</description>
<res-ref-name>jdbc/myConnection</res-ref-name>
<res-type>javax.sql.DataSource</res-type>
<res-auth>Container</res-auth>
</resource-ref>
</web-app>
servlet application
DataSource ds = (DataSource) new InitialContext().lookup("java:comp/env/jdbc/myConnection");
conn = ds.getConnection();
out.println("conn : " + conn);

How to create Connection pool in Tomcat 5

present i am developing one web site in that i am using tomcat 5.
i am trying to establish connection pooling in tomcat,i am facing some problems..
tomcat throws the following exception ie.,
cannot create JDBC Driver class for connect URL null.
my code lik this
i configured the web.xml
<?xml version="1.0" encoding="ISO-8859-1"?>
<web-app>
<resource-ref>
<description>Oracle Datasource example</description>
<res-ref-name>sqlserver</res-ref-name>
<res-type>javax.sql.DataSource</res-type>
<res-auth>Container</res-auth>
</resource-ref>
</web-app>
my server.xml
<?xml version='1.0' encoding='utf-8'?>
<Server>
<Listener className="org.apache.catalina.mbeans.ServerLifecycleListener"/>
<Listener className="org.apache.catalina.mbeans.GlobalResourcesLifecycleListener"/>
<GlobalNamingResources>
<Environment name="simpleValue" type="java.lang.Integer" value="30"/>
<Resource auth="Container" description="User database that can be updated and saved" name="UserDatabase" type="org.apache.catalina.UserDatabase"/>
<Resource auth="Container" name="sqlserver" type="javax.sql.DataSource"/>
<ResourceParams name="UserDatabase">
<parameter>
<name>factory</name>
<value>org.apache.catalina.users.MemoryUserDatabaseFactory</value>
</parameter>
<parameter>
<name>password</name>
<value>sudha</value>
</parameter>
<parameter>
<name>pathname</name>
<value>conf/tomcat-users.xml</value>
</parameter>
<parameter>
<name>username</name>
<value>sudha</value>
</parameter>
</ResourceParams>
<ResourceParams name="sqlserver">
<parameter>
<name>url</name>
<value>jdbc:odbc:SQL</value>
</parameter>
<parameter>
<name>validationQuery</name>
<value>select * from employee</value>
</parameter>
<parameter>
<name>maxIdle</name>
<value>4</value>
</parameter>
<parameter>
<name>maxActive</name>
<value>8</value>
</parameter>
<parameter>
<name>driverClassName</name>
<value>sun.jdbc.odbc.JdbcOdbcDriver</value>
</parameter>
<parameter>
<name>maxWait</name>
<value>5000</value>
</parameter>
<parameter>
<name>username</name>
<value>kpi</value>
</parameter>
<parameter>
<name>factory</name>
<value>org.apache.naming.factory.DbcpDataSourceFactory</value>
</parameter>
<parameter>
<name>password</name>
<value>kpi</value>
</parameter>
</ResourceParams>
</GlobalNamingResources>
<Service name="Catalina">
<Connector acceptCount="100" connectionTimeout="20000" disableUploadTimeout="true" port="8080" redirectPort="8443" maxSpareThreads="75" maxThreads="150" minSpareThreads="25">
</Connector>
<Connector port="8009" protocol="AJP/1.3" protocolHandlerClassName="org.apache.jk.server.JkCoyoteHandler" redirectPort="8443">
</Connector>
<Engine defaultHost="localhost" name="Catalina">
<Host appBase="webapps" name="localhost">
<Logger className="org.apache.catalina.logger.FileLogger" prefix="localhost_log." suffix=".txt" timestamp="true"/>
</Host>
<Logger className="org.apache.catalina.logger.FileLogger" prefix="catalina_log." suffix=".txt" timestamp="true"/>
<Realm className="org.apache.catalina.realm.UserDatabaseRealm"/>
</Engine>
</Service>
</Server>
and i studied the the tomcat documentation in that tomcat mentioned
The configuration properties for Tomcat's standard data source resource factory (org.apache.naming.factory.DbcpDataSourceFactory) are as follows:
driverClassName - Fully qualified Java class name of the JDBC driver to be used.
maxActive - The maximum number of active instances that can be allocated from this pool at the same time.
maxIdle - The maximum number of connections that can sit idle in this pool at the same time.
maxWait - The maximum number of milliseconds that the pool will wait (when there are no available connections) for a connection to be returned before throwing an exception.
password - Database password to be passed to our JDBC driver.
url - Connection URL to be passed to our JDBC driver. (For backwards compatibility, the property driverName is also recognized.)
user - Database username to be passed to our JDBC driver.
validationQuery - SQL query that can be used by the pool to validate connections before they are returned to the application. If specified, this query MUST be an SQL SELECT statement that returns at least one row.
how to configure server.xml file
and how to get the org.apache.naming.factory.DbcpDataSourceFactory
please help me...this module is very very urgen to me..

I spent many hours when i first implemented connection pooling trying to put it together. The information is scattered and the config has changed slightly from 5.0 to 5.5 etc. This is how I got it working in 5.5.17:
* server.xml seems to be a wrong place for the pool configuration if you consider it to be an application specific thing. It might be a better idea to put it into C:\tomcat55\conf\Catalina\localhost\ConfigFileForYourWeapp.xml as follows:
<Context path="/ClientLink" docBase="C:\eclipseWorkspace\PortfolioUI3\WebRoot">
      <Resource name="jdbc/testportfolios" auth="Container"
                     type="javax.sql.DataSource"
                     factory="org.apache.tomcat.dbcp.dbcp.BasicDataSourceFactory"
                     username="****" password="******"
                     driverClassName="com.mysql.jdbc.Driver"
                     url="jdbc:mysql://192.168.0.101:3306/testportfolios?user=***********&password=***********&useUnicode=true&characterSet=swedish"
                     maxWait="10000" maxActive="30" maxIdle="10" removeAbandoned="true"
                     removeAbandonedTimeout="60" logAbandoned="true" testWhileIdle="true"
                     minEvictableIdleTimeMillis="4000"
                     timeBetweenEvictionRunsMillis="60000" validationQuery="SELECT '1'" />
      </Context>* Then add the following snippet into web.xml in your webapp directory:
<resource-ref>
                <description>Database pool defined in ClientLink.xml</description>
                <res-ref-name>jdbc/testportfolios</res-ref-name>
                <res-type>javax.sql.DataSource</res-type>
                <res-auth>Container</res-auth>
           </resource-ref>* Next put the jdbc-driver jar in a place where tomcat can find it. That is common\lib. Note that the shared/lib does not work.
* Get connections in java as follows:
                try {
                     Context initCtx = new InitialContext();
                     DataSource ds = (DataSource) initCtx.lookup("java:comp/env/jdbc/testportfolios");
                     this.connection = ds.getConnection();
                } catch (NamingException e) {
                     throw new RuntimeException("Java naming exception when getting connection from tomcat pool: " + e.getMessage());
                }I hope that this helps you to save the time I lost figuring this out!
Message was edited by:
Tomppu

Jolt client vs. jolt connection pooling

We are porting our app to weblogic. We are current users of jolt but since we weren't
using weblogic
we are currently using jolt client out of the app server. We are examining the merits
of converting to use
the jolt connection pool.
I have been told that jolt client is multi-threaded so the question is: if we convert
to jolt connection pooling
will we see a performance improvement, and if so, why? Or is the advantage purely
from an administrative
standpoint, and if so, what are the advantages there?

Connections are resources that the application uses and a fewer connections can be used by multiple threads if the threads are not always busy with the database activity only, and are doing other work too. This sharing (pooling) can be implemented by the application or the application can leverage the connection pooling features offered by OCI/OCCI (recommended).
Be aware of connections vs sessions and sharing them (refer to :
OCI Programming Advanced Topics
OCCIConnectionPool is to pool connections and OCCIStatelessConnectionPool is to pool sessions. Please see the differences in the above link and apply as appropriate.

Outbound Connection Pool Entry Missing for DBAdapter in Clustered Weblogic Congfiguration

Hi ,
When I created an outbound connection pool entry in DBAdapter through weblogic console in a clustered environment ( 1-Admin server and 2-managed servers) and updated DB adapter, I indentified that connection entry is updated in only in plan.xml of one managed server and for other managed server it is not updated. Due to this we are unable to access Datasources for some requests from application.
As a work around if we update plan.xml file of other managed server manually with required connection entry and update DB Adapter we are able to find the connection entry for both the managed servers.
Apart from work around is there any other solution for this issue so that I can add a DB adapter connection entry through console which will update both plan.xml files.
Thanks & Regards,
Venkat

I can suggest you to keep the Plan.xml file in shared drive that is accessible from all the server nodes,this will reduce the manual work.
Regards
Albin I
http://www.albinsblog.com/

What about session memory when using BEA Weblogic connection pooling?

Hi,
consider a web application, allowing database connections via a BEA Weblogic 8.1 application server. The app-server is pooling the oracle connections. The oracle database is running in dedicated server mode.
How are the database requests from the web app served by the connection pool from BEA?
1) Does one oracle session serve more than one request simultanously?
2) Does BEA serialize the requests, which means, that a session from the pool is always serving only one request at a time?
If (1) is true, than what about the session memory of Oracle sessions? I understand, that things like package global variables are beeing stored in this session private memory. If (1) is true, the PL/SQL programmer has the same situation, as with programming an Oracle databas in "shared server" mode, that is, he should not use package global variables etc.
Thankful for any ideas...
Message was edited by:
Xenofon

Xenofon Grigoriadis wrote:
Hi,
consider a web application, using BEA between client and an Oracle Database (v9i). BEA is pooling the oracle connections. The oracle database is running in dedicated server mode.
How are the database requests from the web app beeing served by the connection pool from BEA?
1) Does one oracle session serve more than one request simultanously?no.
2) Or does BEA serialize the requests, which means, that a session from the pool is always serving only one request at a time?
Reading "Configuring and Using WebLogic JDBC" from weblogic8.1 documentation, I read:
"... Your application "borrows" a connection from the pool, uses it, then returns it to the pool by closing it...."
What do you mean by returning the connection by closing it? Tbe server will either return the connection to the pool or close it...When application code does typical jdbc code, it obtains
a connection via a WebLogic DataSource, which reserves an
unused pooled connection and passes it (transparently wrapped)
to the application. The application uses it, and then closes
it. WebLogic intercepts the close() call via the wrapper, and
puts the DBMS connection back into the WebLogic pool.
The reason, why I as an Oracle programmer ask this is, because every session (=connection)
in Oracle has its own dedicate, private memory for things like global PL/SQL variables.
Now I want to figure out, if you have to careful in programming your databases, when
one Oracle session (=connection) is serving many weblogic requests.It is serving many requests, but always serially. Do note however, that we
also transparently cache/pool prepared and callable statements with the
connection so repeat uses of the connection will be able to get already-made
statements when they call prepareStatement() and prepareCall(). These
long-lived statements will each require a DBMS-side cursor.
>
Thankful for any ideas or practical experience...
Message was edited by:
mk637Joe

Sharing connection pooling ?

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