SAP JCo3 connection pool instance release

Hi Experts,
I am using SAP JCo3 version to connect SAP from remote Java application.I have created connection pool with JcoDestination.
I want to know how to release a Jcodestination (pool instance)once its finishes with the functionalities so that connection pool can be managed properly.
Thanks In advance.

Hi,
I think we dont need to close the connection. Anyway we define Connection Timeout(ms) while JCO Destionations configurations. I guess that is enough.
Size
Currently used
Maximum used
Max.connections
Max.pool size
Connection Timeout(ms)
Max. wait time(ms)
Timeout Check Period(ms)
See the information about connection closing in below link:
http://www.winfobase.de/lehre/lv_materialien.nsf/intern01/FB09D79A41930E34C125709F0046180C/$FILE/Tips&Tricks_JCo_Programming.pdf
Regards,
Charan

Similar Messages

SAP JCo3 connection pooling

Hi,
I am very new to sap jco 3 . I want to make connection pooling using jco3 .But in jco3 there is no class like JCO.Pool
and JCO.Client .I think both class are available in com.sap.mw.jco.* but i dont know from where i can get them .
So, can anybody suggest me how to make connection pooling using SAP Jco3 and how its work ?
Thanks in advance.

This Topic is a litte bit older and I guess you have found an answer yet (at least I hope so )
However here are your answers.
The Pooling is managed within the Destination:
You can set this by createing a DestionationProperty by hand:
Properties connectProperties = new Properties();
connectProperties.setProperty(DestinationDataProvider.JCO_ASHOST, <HOST>);
connectProperties.setProperty(DestinationDataProvider.JCO_SYSNR, <SYS_NR>);
connectProperties.setProperty(DestinationDataProvider.JCO_CLIENT, <e.g. 100>);
connectProperties.setProperty(DestinationDataProvider.JCO_USER, <RFC-User>);
connectProperties.setProperty(DestinationDataProvider.JCO_PASSWD, <pass if working with RFC-User>);
connectProperties.setProperty(DestinationDataProvider.JCO_LANG, <en|de|fr|...>);
connectProperties.setProperty(DestinationDataProvider.JCO_POOL_CAPACITY, <e.g. 3>);
connectProperties.setProperty(DestinationDataProvider.JCO_PEAK_LIMIT, <e.g. 10>);
Due to seurity reasons this is not the recommended way. But since I guess your code will run on some SAP-ApplicationSserver in the end you can easyly set the Destionation properties in the NetWeaver Administrator (http://<server>:<port>/nwa) under Konfiguration -> Security -> Destinations
then you can use:
JCoDestinationManager.getDestination(<destinationName>);
to get a JCoDestination. This is more or less what you wanted with JCO.Client
I know the documentation on this Topic is not very detailed but with this few informations you should find what you need.

Configuring JCo3 Connection Pool with single sign on on non SAP Java server

Hi Everyone,
i have configured a connection pool on JBoss as per JCo3 Documentation and is working great.
Now I need help to configure this connection pool with single sign on so that RFc on SAP ECC systems are executed using end users credential rather than using single user name password used to configure JCo connection pool.
On SAP Java stack I am sure its possible within Java WebDynpro and i assume using JCA resource adapter. But what if we don't want to use SAP Java App server.
Any help will be appreciated.
Thanks,
Divyakumar Jain

Eason, 你好！
I have exactly the same problem. Did you find a solution to this problem? If so, please let me know!

Weblogic 9.2 - Problem with Connection Pool not releasing resources

We have a third party application that is running Weblogic 9.2 and has a connection pool to a SQL 2005 db for queries within it's batch process. What I have noticed is that it does not seem to be releasing SQL cpu back after the batch and this is causing issues with processes for other dB's within the instance. Has anyone encountered this issue and if so what is the solution (short of isolating it within it's own instance). Can the connection be reset to release resources?

Yes it is a weblogic connection pool. What I mean is that when a batch run I can see the CPU for the SQL process associated with the connection increase but when the batch is completed the CPU remains high when I would expect it to move back down to an 'idle' level as after that as all it would be doing is the occasional "select 1' ping to keep the connection active.
What i do see is that the cpu in activity monitor shows high cpu and it never goes down unless the connection is killed and re-established. As this is a shared instance other apps are complaining of slow running procs.

Connection pool for ldap

Hi
My application is an interface to ldap directory. I have not used any ldap open source api to retrieve data from ldap. I have written connection pool that will help the application to connect to the ldap. It's working fine, but it's creating threads which are not invited.
ConnectionPool class takes care of the connection storage and creation, while Housekeeping thread relases these connection when idle after a given time.
Can someone please help in finding the problem in the code that creates additional threads.
package com.ba.cdLookup.manager;
import com.ba.cdLookup.exception.CDLookupException;
import com.ba.cdLookup.server.CdLookupProperties;
import java.util.Vector;
import javax.naming.Context;
import javax.naming.NamingException;
public class HouseKeeperThread extends Thread {
 * Apache Logger to log erro/info/debug statements.
 protected static org.apache.commons.logging.Log log = org.apache.axis.components.logger.LogFactory
 .getLog(HouseKeeperThread.class.getName());
 private static HouseKeeperThread houseKeeperThread;
 * Close all connections existing.
 * @param connections
 * void
 private void closeConnections(Vector connections) {
 String methodIdentifier = "closeConnections";
 int numOfConn = connections.size();
 try {
 for (int i = 0; i < numOfConn; i++) {
 Context context = (Context) connections.get(i);
 if (context != null) {
 context.close();
 context = null;
 connections.remove(i);
 numOfConn--;
 log.info(" connection name:" + context
 + " removed. Threadcount =" + (connections.size()));
 } catch (NamingException e) {
 String errMsg = "CDLdapBuilder connect() - failure while releasing connection "
 + " Exception is " + e.toString();
 log.error(errMsg);
 } catch (Exception e) {
 String errMsg = "CDLdapBuilder connect() - failure while releasing connection "
 + " Exception is " + e.toString();
 log.error(errMsg);
 * Thread run method
 public void run() {
 String methodIdentifier = "run";
 try {
 while(true){
 log.debug("house keeping :" + this + " ---sleep");
 //sleep(100000);
 log.debug("house keeping :" + this + " startd after sleep");
 sleep(CdLookupProperties.getHouseKeepConnectionTime());
 ConnectionPool connectionPool = ConnectionPool
 .getConnectionPool();
 Vector connList = connectionPool.getAvailableConnections();
 closeConnections(connList);
 } catch (CDLookupException cde) {
 log.error(methodIdentifier + " " + cde.getStackTrace());
 } catch (InterruptedException ie) {
 log.error(methodIdentifier + " " + ie.getStackTrace());
 * @param connectionPool
 * @return
 * Thread
 public static Thread getInstance() {
 if(houseKeeperThread==null){
 houseKeeperThread = new HouseKeeperThread();
 return houseKeeperThread ;
package com.ba.cdLookup.manager;
import com.ba.cdLookup.exception.CDLookupException;
import com.ba.cdLookup.server.CdLookupProperties;
import com.ba.cdwebservice.schema.cdLookupPacket.LookupFailureReasons;
import java.util.Properties;
import java.util.Vector;
import javax.naming.Context;
import javax.naming.NamingException;
import javax.naming.directory.DirContext;
import javax.naming.directory.InitialDirContext;
* ConnectionPool class manages, allocates LDAP connections. It works as a lazy
* binder and retrieves connections only when required. It doesn't allow
* connection greater then the maximum connection stated.
* To retrieve a connection the singelton method getConnectionPool is to used,
* which retruns thread safe singleton object for the connection.
public class ConnectionPool implements Runnable {
 private int initialConnections = 0;
 private int maxConnections = 0;
 private boolean waitIfBusy = false;
 private Vector availableConnections, busyConnections;
 private boolean connectionPending = false;
 private static int threadCount = 0;
 * classIdentifier
 private final String classIdentifier = "ConnectionPool";
 * Apache Logger to log erro/info/debug statements.
 protected static org.apache.commons.logging.Log log = org.apache.axis.components.logger.LogFactory
 .getLog(CDLdapBuilder.class.getName());
 * To get the attribute a systemaccessfor out of the search result
 private String vendorContextFactoryClass = "com.sun.jndi.ldap.LdapCtxFactory";// "com.ibm.jndi.LDAPCtxFactory";
 * context factory to use
 private String ldapServerUrl = "LDAP://test.ldap.com"; // default ldap
 * server live used by default
 private String searchBase;
 * environment properties.
 private Properties env;
 * DirContext
 private javax.naming.directory.DirContext ctx;
 * default search base to be used in Corporate Directory searches
 private String defaultSearchBase = "dc=Pathway";
 * search criteria
 private String searchAttributes;
 * search filter to retrieve data from CD
 private String searchFilter;
 * CorporateDirectoryLookup Constructor
 * 
 * loads the setup parameters from the properties file and stores them
 * Makes a connection to the directory and sets default search base
 * @throws CDLookupException
 * @throws CDLookupException
 private ConnectionPool() throws CDLookupException {
 this.maxConnections = CdLookupProperties.getMaxConnection();// maxConnections;
 this.initialConnections = CdLookupProperties.getInitialConnection();
 this.waitIfBusy = CdLookupProperties.isWaitIfBusy();
 this.searchBase = CdLookupProperties.getDefaultSearchBase();
 //for local env testing
// this.maxConnections = 5;
// this.initialConnections = 1;
// this.waitIfBusy = true;
 * For keeping no of connections in the connection pool if
 * (initialConnections > maxConnections) { initialConnections =
 * maxConnections; }
 availableConnections = new Vector(maxConnections);
 busyConnections = new Vector(maxConnections);
 for (int i = 0; i < maxConnections; i++) {
 availableConnections.add(makeNewConnection());
 * ConnectionPoolHolder provide Thread safe singleton
 * instance of ConnectionPool class
 private static class ConnectionPoolHolder {
 * connection pool instance
 private static ConnectionPool connectionPool = null;
 * If no ConnectionPool object is present, it creates instance of
 * ConnectionPool class and initiates thread on that.
 * @return ConnectionPool Returns singleton object of ConnectionPool
 * class.
 * @throws CDLookupException
 private static ConnectionPool getInstance() throws CDLookupException {
 if (connectionPool == null) {
 connectionPool = new ConnectionPool();
 new Thread(connectionPool).start();
 // Initiate house keeping thread.
 HouseKeeperThread.getInstance().start();
 return connectionPool;
 * Returns singleton object of ConnectionPool class.
 * @return ConnectionPool
 * @throws CDLookupException
 public static ConnectionPool getConnectionPool() throws CDLookupException {
 return ConnectionPoolHolder.getInstance();
 * getConnection retrieves connections to the corp directory. In case
 * there is no available connections in the pool then it'll try to
 * create one, if the max connection limit for the connection pool
 * reaches then this waits to retrieve one.
 * @return Context
 * @throws CDLookupException
 public synchronized Context getConnection() throws CDLookupException {
 String methodIdentifier = "getConnection";
 if (!availableConnections.isEmpty()) {
 int connectionSize = availableConnections.size() - 1;
 DirContext existingConnection = (DirContext) availableConnections
 .get(connectionSize);
 availableConnections.remove(connectionSize);
 * 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 == null) {
 notifyAll(); // Freed up a spot for anybody waiting
 return (getConnection());
 } else {
 busyConnections.add(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 CDLookupException("Connection limit reached", 0);
 * 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) {
 String errMsg = "Exception raised =" + ie.getStackTrace();
 log.error(errMsg);
 throw new CDLookupException(classIdentifier, methodIdentifier,
 errMsg, ie);
 // connection freed up, 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);
 log.debug("background thread created");
 connectThread.start();
 } catch (OutOfMemoryError oome) {
 log.error("makeBackgroundConnection ="+ oome.getStackTrace());
 * Thread run method
 public void run() {
 String methodIdentifier = "run";
 try {
 Context connection = makeNewConnection();
 synchronized (this) {
 availableConnections.add(connection);
 connectionPending = false;
 notifyAll();
 } catch (Exception e) { // SQLException or OutOfMemory
 // Give up on new connection and wait for existing one
 // to free up.
 String errMsg = "Exception raised =" + e.getStackTrace();
 log.error(errMsg);
 * This explicitly makes a new connection. Called in the foreground when
 * initializing the ConnectionPool, and called in the background when
 * running.
 * @return Context
 * @throws CDLookupException
 private Context makeNewConnection() throws CDLookupException {
 String methodIdentifier = "makeNewConnection";
 Context context = null;
 env = new Properties();
 log.debug("inside " + methodIdentifier);
 try {
 env.put(Context.INITIAL_CONTEXT_FACTORY,
 getVendorContextFactoryClass());
 env.put(Context.PROVIDER_URL, getLdapServerUrl());
 env.put("com.sun.jndi.ldap.connect.pool", "true");
 context = new InitialDirContext(env);
 } catch (NamingException e) {
 String errMsg = "CDLdapBuilder connect() - failure while attempting to contact "
 + ldapServerUrl + " Exception is " + e.toString();
 throw new CDLookupException(classIdentifier, methodIdentifier,
 errMsg, e, LookupFailureReasons.serviceUnavailable);
 } catch (Exception e) {
 String errMsg = "CDLdapBuilder connect() - failure while attempting to contact "
 + ldapServerUrl + " Exception is " + e.toString();
 throw new CDLookupException(classIdentifier, methodIdentifier,
 errMsg, e, LookupFailureReasons.serviceUnavailable);
 log.info("new connection :" + (threadCount++) + " name =" + context);
 log.debug("exit " + methodIdentifier);
 return context;
 * releases connection to the free pool
 * @param context
 public synchronized void free(Context context) {
 busyConnections.remove(context);
 availableConnections.add(context);
 // Wake up threads that are waiting for a connection
 notifyAll();
 * @return int give total no of avail connections.
 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 required 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();
 * Close all connections existing.
 * @param connections
 * void
 private void closeConnections(Vector connections) {
 String methodIdentifier = "closeConnections";
 try {
 for (int i = 0; i < connections.size(); i++) {
 Context context = (Context) connections.get(i);
 if (context != null) {
 log.info(" connection name:" + context
 + " removed. Threadcount =" + (threadCount++));
 context.close();
 context = null;
 } catch (NamingException e) {
 String errMsg = "CDLdapBuilder connect() - failure while attempting to contact "
 + ldapServerUrl + " Exception is " + e.toString();
 log.error(errMsg);
 public synchronized String toString() {
 String info = "ConnectionPool(" + getLdapServerUrl() + ","
 + getVendorContextFactoryClass() + ")" + ", available="
 + availableConnections.size() + ", busy="
 + busyConnections.size() + ", max=" + maxConnections;
 return (info);
 * @return the defaultSearchBase
 public final String getDefaultSearchBase() {
 return defaultSearchBase;
 * @param defaultSearchBase
 * the defaultSearchBase to set
 public final void setDefaultSearchBase(String defaultSearchBase) {
 this.defaultSearchBase = defaultSearchBase;
 * @return the ldapServerUrl
 public final String getLdapServerUrl() {
 return ldapServerUrl;
 * @param ldapServerUrl
 * the ldapServerUrl to set
 public final void setLdapServerUrl(String ldapServerUrl) {
 this.ldapServerUrl = ldapServerUrl;
 * @return the vendorContextFactoryClass
 public final String getVendorContextFactoryClass() {
 return vendorContextFactoryClass;
 * @param vendorContextFactoryClass
 * the vendorContextFactoryClass to set
 public final void setVendorContextFactoryClass(
 String vendorContextFactoryClass) {
 this.vendorContextFactoryClass = vendorContextFactoryClass;
 * @return the availableConnections
 public final Vector getAvailableConnections() {
 return availableConnections;
}

Hi,
As the connection pool implmentation has the bug of not extending more than the min size, workaround I use is MIN_CONN=100 and MAX_CONN=101,and just waiting for the bug to get fixed. (using Netscape SDK for java4.0)

Threading with connection pool

Hi
My application is an interface to ldap directory. I have not used any ldap open source api to retrieve data from ldap. I have written connection pool that will help the application to connect to the ldap. It's working fine, but it's creating threads which are not invited.
ConnectionPool class takes care of the connection storage and creation, while Housekeeping thread relases these connection when idle after a given time.
Can someone please help in finding the problem in the code that creates additional threads.
package com.ba.cdLookup.manager;
import com.ba.cdLookup.exception.CDLookupException;
import com.ba.cdLookup.server.CdLookupProperties;
import java.util.Vector;
import javax.naming.Context;
import javax.naming.NamingException;
public class HouseKeeperThread extends Thread {
 * Apache Logger to log erro/info/debug statements.
 protected static org.apache.commons.logging.Log log = org.apache.axis.components.logger.LogFactory
 .getLog(HouseKeeperThread.class.getName());
 private static HouseKeeperThread houseKeeperThread;
 * Close all connections existing.
 * @param connections
 * void
 private void closeConnections(Vector connections) {
 String methodIdentifier = "closeConnections";
 int numOfConn = connections.size();
 try {
 for (int i = 0; i < numOfConn; i++) {
 Context context = (Context) connections.get(i);
 if (context != null) {
 context.close();
 context = null;
 connections.remove(i);
 numOfConn--;
 log.info(" connection name:" + context
 + " removed. Threadcount =" + (connections.size()));
 } catch (NamingException e) {
 String errMsg = "CDLdapBuilder connect() - failure while releasing connection "
 + " Exception is " + e.toString();
 log.error(errMsg);
 } catch (Exception e) {
 String errMsg = "CDLdapBuilder connect() - failure while releasing connection "
 + " Exception is " + e.toString();
 log.error(errMsg);
 * Thread run method
 public void run() {
 String methodIdentifier = "run";
 try {
 while(true){
 log.debug("house keeping :" + this + " ---sleep");
 //sleep(100000);
 log.debug("house keeping :" + this + " startd after sleep");
 sleep(CdLookupProperties.getHouseKeepConnectionTime());
 ConnectionPool connectionPool = ConnectionPool
 .getConnectionPool();
 Vector connList = connectionPool.getAvailableConnections();
 closeConnections(connList);
 } catch (CDLookupException cde) {
 log.error(methodIdentifier + " " + cde.getStackTrace());
 } catch (InterruptedException ie) {
 log.error(methodIdentifier + " " + ie.getStackTrace());
 * @param connectionPool
 * @return
 * Thread
 public static Thread getInstance() {
 if(houseKeeperThread==null){
 houseKeeperThread = new HouseKeeperThread();
 return houseKeeperThread ;
package com.ba.cdLookup.manager;
import com.ba.cdLookup.exception.CDLookupException;
import com.ba.cdLookup.server.CdLookupProperties;
import com.ba.cdwebservice.schema.cdLookupPacket.LookupFailureReasons;
import java.util.Properties;
import java.util.Vector;
import javax.naming.Context;
import javax.naming.NamingException;
import javax.naming.directory.DirContext;
import javax.naming.directory.InitialDirContext;
* ConnectionPool class manages, allocates LDAP connections. It works as a lazy
* binder and retrieves connections only when required. It doesn't allow
* connection greater then the maximum connection stated.
* To retrieve a connection the singelton method getConnectionPool is to used,
* which retruns thread safe singleton object for the connection.
public class ConnectionPool implements Runnable {
 private int initialConnections = 0;
 private int maxConnections = 0;
 private boolean waitIfBusy = false;
 private Vector availableConnections, busyConnections;
 private boolean connectionPending = false;
 private static int threadCount = 0;
 * classIdentifier
 private final String classIdentifier = "ConnectionPool";
 * Apache Logger to log erro/info/debug statements.
 protected static org.apache.commons.logging.Log log = org.apache.axis.components.logger.LogFactory
 .getLog(CDLdapBuilder.class.getName());
 * To get the attribute a systemaccessfor out of the search result
 private String vendorContextFactoryClass = "com.sun.jndi.ldap.LdapCtxFactory";// "com.ibm.jndi.LDAPCtxFactory";
 * context factory to use
 private String ldapServerUrl = "LDAP://test.ldap.com"; // default ldap
 * server live used by default
 private String searchBase;
 * environment properties.
 private Properties env;
 * DirContext
 private javax.naming.directory.DirContext ctx;
 * default search base to be used in Corporate Directory searches
 private String defaultSearchBase = "dc=Pathway";
 * search criteria
 private String searchAttributes;
 * search filter to retrieve data from CD
 private String searchFilter;
 * CorporateDirectoryLookup Constructor
 * 
 * loads the setup parameters from the properties file and stores them
 * Makes a connection to the directory and sets default search base
 * @throws CDLookupException
 * @throws CDLookupException
 private ConnectionPool() throws CDLookupException {
 this.maxConnections = CdLookupProperties.getMaxConnection();// maxConnections;
 this.initialConnections = CdLookupProperties.getInitialConnection();
 this.waitIfBusy = CdLookupProperties.isWaitIfBusy();
 this.searchBase = CdLookupProperties.getDefaultSearchBase();
 //for local env testing
// this.maxConnections = 5;
// this.initialConnections = 1;
// this.waitIfBusy = true;
 * For keeping no of connections in the connection pool if
 * (initialConnections > maxConnections) { initialConnections =
 * maxConnections; }
 availableConnections = new Vector(maxConnections);
 busyConnections = new Vector(maxConnections);
 for (int i = 0; i < maxConnections; i++) {
 availableConnections.add(makeNewConnection());
 * ConnectionPoolHolder provide Thread safe singleton
 * instance of ConnectionPool class
 private static class ConnectionPoolHolder {
 * connection pool instance
 private static ConnectionPool connectionPool = null;
 * If no ConnectionPool object is present, it creates instance of
 * ConnectionPool class and initiates thread on that.
 * @return ConnectionPool Returns singleton object of ConnectionPool
 * class.
 * @throws CDLookupException
 private static ConnectionPool getInstance() throws CDLookupException {
 if (connectionPool == null) {
 connectionPool = new ConnectionPool();
 new Thread(connectionPool).start();
 // Initiate house keeping thread.
 HouseKeeperThread.getInstance().start();
 return connectionPool;
 * Returns singleton object of ConnectionPool class.
 * @return ConnectionPool
 * @throws CDLookupException
 public static ConnectionPool getConnectionPool() throws CDLookupException {
 return ConnectionPoolHolder.getInstance();
 * getConnection retrieves connections to the corp directory. In case
 * there is no available connections in the pool then it'll try to
 * create one, if the max connection limit for the connection pool
 * reaches then this waits to retrieve one.
 * @return Context
 * @throws CDLookupException
 public synchronized Context getConnection() throws CDLookupException {
 String methodIdentifier = "getConnection";
 if (!availableConnections.isEmpty()) {
 int connectionSize = availableConnections.size() - 1;
 DirContext existingConnection = (DirContext) availableConnections
 .get(connectionSize);
 availableConnections.remove(connectionSize);
 * 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 == null) {
 notifyAll(); // Freed up a spot for anybody waiting
 return (getConnection());
 } else {
 busyConnections.add(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 CDLookupException("Connection limit reached", 0);
 * 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) {
 String errMsg = "Exception raised =" + ie.getStackTrace();
 log.error(errMsg);
 throw new CDLookupException(classIdentifier, methodIdentifier,
 errMsg, ie);
 // connection freed up, 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);
 log.debug("background thread created");
 connectThread.start();
 } catch (OutOfMemoryError oome) {
 log.error("makeBackgroundConnection ="+ oome.getStackTrace());
 * Thread run method
 public void run() {
 String methodIdentifier = "run";
 try {
 Context connection = makeNewConnection();
 synchronized (this) {
 availableConnections.add(connection);
 connectionPending = false;
 notifyAll();
 } catch (Exception e) { // SQLException or OutOfMemory
 // Give up on new connection and wait for existing one
 // to free up.
 String errMsg = "Exception raised =" + e.getStackTrace();
 log.error(errMsg);
 * This explicitly makes a new connection. Called in the foreground when
 * initializing the ConnectionPool, and called in the background when
 * running.
 * @return Context
 * @throws CDLookupException
 private Context makeNewConnection() throws CDLookupException {
 String methodIdentifier = "makeNewConnection";
 Context context = null;
 env = new Properties();
 log.debug("inside " + methodIdentifier);
 try {
 env.put(Context.INITIAL_CONTEXT_FACTORY,
 getVendorContextFactoryClass());
 env.put(Context.PROVIDER_URL, getLdapServerUrl());
 env.put("com.sun.jndi.ldap.connect.pool", "true");
 context = new InitialDirContext(env);
 } catch (NamingException e) {
 String errMsg = "CDLdapBuilder connect() - failure while attempting to contact "
 + ldapServerUrl + " Exception is " + e.toString();
 throw new CDLookupException(classIdentifier, methodIdentifier,
 errMsg, e, LookupFailureReasons.serviceUnavailable);
 } catch (Exception e) {
 String errMsg = "CDLdapBuilder connect() - failure while attempting to contact "
 + ldapServerUrl + " Exception is " + e.toString();
 throw new CDLookupException(classIdentifier, methodIdentifier,
 errMsg, e, LookupFailureReasons.serviceUnavailable);
 log.info("new connection :" + (threadCount++) + " name =" + context);
 log.debug("exit " + methodIdentifier);
 return context;
 * releases connection to the free pool
 * @param context
 public synchronized void free(Context context) {
 busyConnections.remove(context);
 availableConnections.add(context);
 // Wake up threads that are waiting for a connection
 notifyAll();
 * @return int give total no of avail connections.
 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 required 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();
 * Close all connections existing.
 * @param connections
 * void
 private void closeConnections(Vector connections) {
 String methodIdentifier = "closeConnections";
 try {
 for (int i = 0; i < connections.size(); i++) {
 Context context = (Context) connections.get(i);
 if (context != null) {
 log.info(" connection name:" + context
 + " removed. Threadcount =" + (threadCount++));
 context.close();
 context = null;
 } catch (NamingException e) {
 String errMsg = "CDLdapBuilder connect() - failure while attempting to contact "
 + ldapServerUrl + " Exception is " + e.toString();
 log.error(errMsg);
 public synchronized String toString() {
 String info = "ConnectionPool(" + getLdapServerUrl() + ","
 + getVendorContextFactoryClass() + ")" + ", available="
 + availableConnections.size() + ", busy="
 + busyConnections.size() + ", max=" + maxConnections;
 return (info);
 * @return the defaultSearchBase
 public final String getDefaultSearchBase() {
 return defaultSearchBase;
 * @param defaultSearchBase
 * the defaultSearchBase to set
 public final void setDefaultSearchBase(String defaultSearchBase) {
 this.defaultSearchBase = defaultSearchBase;
 * @return the ldapServerUrl
 public final String getLdapServerUrl() {
 return ldapServerUrl;
 * @param ldapServerUrl
 * the ldapServerUrl to set
 public final void setLdapServerUrl(String ldapServerUrl) {
 this.ldapServerUrl = ldapServerUrl;
 * @return the vendorContextFactoryClass
 public final String getVendorContextFactoryClass() {
 return vendorContextFactoryClass;
 * @param vendorContextFactoryClass
 * the vendorContextFactoryClass to set
 public final void setVendorContextFactoryClass(
 String vendorContextFactoryClass) {
 this.vendorContextFactoryClass = vendorContextFactoryClass;
 * @return the availableConnections
 public final Vector getAvailableConnections() {
 return availableConnections;
}

hi ejp
Thx for the reply.
// Enable connection pooling
env.put("com.sun.jndi.ldap.connect.pool", "true");
Is this suffice to get the connection pool working,
Should i merely have a thread to maintain the connection with the ldap that uses sun's connection pool; or allow requestes to create new object for the connection and still this pool will hold.
for example in the above code instead to housekeep the thread merely maintain connection with the pool
or
should I directly connect each object with the ldap?
I am unable to understand how exactly sun's connection pool is working and how it should be used. I have gone thru the following example but picture is still hazy and undigestable to me.
java.sun.com/products/jndi/tutorial/ldap/connect/pool.html
Rgds

PI' RFC Connection pool doubt.

Hi PI exports:
i have a doubt about pi' RFC Connection pool ,pi RFC receive channel can set the conn pool size ,but when start the rfc receiver channel ,is there always only one Connection pool ,or there is only one Connection pool instance?
thinks
Edited by: kevin liang on Oct 19, 2009 6:45 AM

Hi,
Connection poolins size means how many number of connection you want to make open to send data to ECC, We can define maximum number of connection in Receiver RFC Adapter,Go to additional parameters section and define Max Number of connection give the number there,thats it.Internally it works as Connection poolin mechanism.
Regards,
Raj

[原创] 有关Weblogic Connection Pool 连接恢复的问题

这是一个古老的问题，一直困扰我，这里既然碰到了，就看看能不能解决。
环境描述：
WEBLOGIC版本是8.1 SP2，数据库是SQL SERVER 2000，分别部署在两个服务器上。
第一步：
问题描述：
数据库服务器重新启动，导致WEBLOGIC 的CONNECTION POOL中的连接中断，EJB无法获得连接，导致应用出错。
解决方法：
进入WEBLOGIC ADMIN CONSOLE,
Services->JDBC->Connection Pools->Config->Connections，点开Advanced Options.
打开 Test Reserved Connections ，Test Created Connections，Test Released Connections这三个选项。
将Test Table Name属性设置为:sysproperties(SQL Server系统表，即使自己的应用不存在，这个表也存在，而且默认的内部没有数据)
根据如下解释：
Connections that fail the test are closed and reopened to re-establish a valid physical database connection.
(You must specify a Test Table Name below.)
每次调用首先进行测试连接，如果测试失败连接将重新建立。
测试结果：
WEBLOGIC启动后，关闭数据库SQL SERVER，应用服务器前端调用此时失败。
重新启动SQL SERVER后，WEBLOGIC端略做等待，前端应用恢复正常。
第二步：
问题描述：
进一步测试，如果WEBLOGIC先启动，启动完成后再启动数据库。
在WEBLOGIC CONSOLE得到如下输出：
<2006-3-22 上午11时50分08秒 GMT+08:00> <Warning> <JDBC> <BEA-001129> <Received exception while creating connection for p
ool "MyJDBC Connection Pool": [Microsoft][SQLServer 2000 Driver for JDBC]Error establishing socket.>
<2006-3-22 上午11时50分10秒 GMT+08:00> <Error> <JDBC> <BEA-001150> <Connection Pool "MyJDBC Connection Pool" deployment
failed with the following error: 0:Could not create pool connection. The DBMS driver exception was: [Microsoft][SQLServe
r 2000 Driver for JDBC]Error establishing socket..>
<2006-3-22 上午11时50分10秒 GMT+08:00> <Error> <JDBC> <BEA-001151> <Data Source "MyJDBC Data Source" deployment failed w
ith the following error: DataSource(jdbc/OMSEIITxDS) can't be created with non-existent Pool (connection or multi) (MyJD
BC Connection Pool).>
Unable to deploy EJB: XXXXXXX from XXXXXXX.jar:
[EJB:011028]The DataSource with the JNDI name: jdbc/XXXXXX could not be located. Please ensure that the DataSource h
as been deployed successfully and that the JNDI name in your EJB Deployment descriptor is correct.
1、在默认初始化打开的连接一一失败以后，连接池发现可用的连接为0，郁闷的宣布自己部署失败。
2、接着数据源发现没有可用的连接池，自己也宣布部署失败。
3、下面所有的EJB发现不了数据源的JNDI名，部署也全部失败。
应用启动完成后，大部分EJB的状态为INACTIVE。前端应用无法使用，此时启动数据库，前端应用无法使用。
手动重新部署 EJB失败,错误还是找不到JNDI，前端应用无法使用。
手动重新部署连接池，数据源后，部署EJB 依然失败。前端应用无法使用。
解决方法：
进入WEBLOGIC ADMIN CONSOLE,
Services->JDBC->Connection Pools->Config->Connections，点开Advanced Options.
将
Connection Creation Retry Frequency 参数设置为 60。
ConnectionCreationRetryFrequencySeconds含义：
当创建数据库连接时,如果数据库不可用(如数据库没启动),隔多长时间试着重新创建该连接,
WLS8.1会每隔ConnectionCreationRetryFrequencySeconds秒重试一次.直到JDBC POOL创建成功
参考：http://dev2dev.bea.com.cn/techdoc/20030469.html，‘JDBC Connect Pool’部分。
英文解释可以直接控制台上看到，或者edocs查。
测试结果：
将数据库关闭，WEBLOGIC重新启动。
在WEBLOGIC CONSOLE得到如下输出：
打开Connection Creation Retry Frequency 参数后，连接池在第一轮尝试失败以后，就成功部署了，数据源也成功部署。
EJB部署会失败，但是提示也与先前的不同：
Unable to deploy EJB: XXXXXXX from XXXXXXX.jar:
weblogic.common.resourcepool.ResourceLimitException: No resources currently available in pool MyJDBC Connection Pool to
allocate to applications, please increase the size of the pool and retry..
每隔一段时间会看到，CONNECTION POOL不断的重新进行连接：
<2006-3-22 下午12时17分56秒 GMT+08:00> <Warning> <JDBC> <BEA-001129> <Received exception while creating connection for p
ool "MyJDBC Connection Pool": [Microsoft][SQLServer 2000 Driver for JDBC]Error establishing socket.>
在WEBLOGIC启动完成后，所有EJB为INACTIVE状态。
启动数据库服务器，稍后，手动重新部署所有的EJB，EJB可以部署成功，前端应用可以正常使用。
此时，此问题已经基本解决，仍需要手动部署EJB。
第三步：
问题描述：
解决方法：
有关部署次序的问题，首先查阅WEBLOGIC文档，http://edocs.bea.com/wls/docs81/faq/deploy.html#744900，得到
WebLogic Server deploys server-level resources (first JDBC and then JMS) before deploying applications.
Applications are deployed in this order: connectors, then EJBs, then Web Applications.
If the application is an EAR, the individual components are loaded in the order in which they are declared
in the application.xml deployment descriptor.
WEBLOGIC先部署服务器端资源，JDBC -> JMS....，然后部署我们的应用，EJB->WEB APPLICATION。
实际从WEBLOGIC启动日志来看，即使打开了Connection Creation Retry Frequency，如果当时数据库不是可用的，CONNECTION POOL
会不断的调度CONNECTION进行重新连接。但是此时，EJB的部署也同时在进行。个人猜测这应该是两个不同的线程（组）分别调度的任务。
现在考虑的是能不能用StartupClass截住EJB的部署过程，粗略的说是如果DATASOURCE没有连接好，或者没有可用的连接池，
就不往下进行EJB部署的过程。
参考：http://edocs.bea.com/wls/docs81/config_xml/EJBComponent.html#DeploymentOrder
DeploymentOrder：
A priority that the server uses to determine when it deploys an item. The priority is relative to other deployable
items of the same type. For example, the server prioritizes and deploys all EJBs before it prioritizes and
deploys startup classes.Items with the lowest Deployment Order value are deployed first.
There is no guarantee on the order of deployments with equal Deployment Order values.
There is no guarantee of ordering across clusters. Default: 1000 Minimum: 0 Maximum: 2N31-1
在部署同一类应用时，按照 DEPLOYMENT LOADER的数值决定，数值越小越先。（EJB的参数在ADMIN CONSOLE界面上叫做LOAD ORDER)
而且上面看来服务器是先部署EJB，再部署STARTUP CLASS，遗憾了。
好在STARTUP CLASS上有两个选项，
Run Before Application Deployments
Run Before Application Activations
这两个选项分别可以设置StartupClass分别在系统资源部署之前，以及在系统资源部署和用户应用部署之间启动。
选上Run Before Application Activations。
现在可以了，我写了一个STARTUP CLASS，思路见下：
主代码：
private void testConnection(){
while (!isTimeout() && !getConnection()){
try{
Thread.sleep(testInterval*1000);
}catch(Exception ignor){}
log("DBConnectHolder job finished with following status:");
log("Timeout:"+isTimeout +",Connection OK:"+isConnected);
测试结果：
只要配置的等待时间足够长，应用服务器先行启动的情况下，等待数据库启动后才进行EJB等等的部署。
（主要考虑如果数据库连接不OK，EJB启动了也没有太大用，还得手工重新部署。）算是比较完满的解决了问题。
另外一个思路是是否可行？通过MBean, 在CONNECTION 建立起来以后通知一把，进行EJB的重新部署。
没来得及研究，请有经验的同学帮我补充完善。
结论：
其实也没什么结论，只是把自己遇到问题，解决问题的思路写了一下。短时间内阅读的文献有限，可能采用了一些苯方法
，或者走了弯路，也请大家拍砖。
在WL8版本上，数据库连接进行恢复和重新连接的时候，上面提出的几个参数应该是比较重要的，我再次强调一下。
Services->JDBC->Connection Pools->Config->Connections，点开Advanced Options.
Test Reserved Connections
Test Created Connections
Test Released Connections
Test Table Name
Connection Creation Retry Frequency

在第一个情景中应该只需要打开Test Reserved Connections 就可以了。
Test Created Connections表示创建连接后放到pool之前进行测试看连接是否可用
Test Released Connections表示释放连接回到pool之前进行测试看连接是否可用
I think so！

Connection Pooling: Do I have to do anything special to use it?

All,
I've a question about connection pooling. This is my scenario:
* Web user makes a request.
* Request comes to a module (M1).
* M1 calls my module (M2).
* M1 and M2 are both java libraries.
This is what M1 does:
* It does a JNDI lookup and gets an object (that is basically the handle) to connect to M2.
* This object has the database connect string attached to it.
* M1 uses this object and calls, say, a login() method of M2.
* At this point, M2 connects to a database.
I use Oracle's thin driver and I've enabled connection caching (which is what it is called in 10g) using DataSource.setConnectionCachingEnabled(true).
The question I have is -
1. Does this ensure that I get a connection from the pool everytime? Or, do I need to do something more to enforce that?
2. I do a
OracleDataSource ds = new OracleDataSource();each time a connection is requested, but, however, I do this -
Connection conn = ds.getConnection(); only if (conn == null) || (conn.isClosed) .
3. Finally, I've a test java application (not a web application) that calls M2. Even if connection pooling were to work above, would it work in this case given that I'm not using any web server (for testing)?
Thanks for your help.

Your connection pooling part seems fine to me unless I missed out something.
One thing I would like to say is that you should close the connection by calling the close() method each time the job is done. Closing the connection does not physically close it. It only sends it back to the connection pool and release the resources held up by that connection.
In that case, you should not need a check like (conn == null) || (conn.isClosed).
Finally, even if the application is stand alone, the connection pool can be used as long as the DataSource could be looked up.

SAP J2EE 6.20 DB Connection Pool Strangeness

Has anyone seen a problem with the SAP J2EE dbpool service whereby no matter how big the connection pool is set to be only a single connection ever seems to be used by applications ?
This is clustered SAP J2EE SP18 (67440.20) connection to an AS/400 using the IBM jt400 driver.
Bizarrely similar applications using a different connection pool (but the same driver and back end AS/400) continue to work as normal - creating multiple "used" connections as and when required.
Many thanks for any pointers !!

used SQL tool to migrate.
used SAP note : 1271375

Universal Connection Pool license and release policy

Hi,
the Oracle JDBC drivers are licensed by the "Oracle Technology Network Development and Distribution License Terms" which allows you to distribute the JDBC drivers with your software without the need to purchase any additional license from Oracle.
UCP is licensed by the "Oracle Technology Network Developer License Terms". This license is the same you get for your development version of the database itself, meaning that you are not allowed to use the software for any production use or development of an already released software.
This is irritating, since I cannot see that I can purchase a license for UCP to distribute UCP with my software. In addition, the version of UCP currently available at oracle.com is not the most current one (11.2.0.1.0; Oracle database patchset 11.2.0.2.0 contains UCP version 11.2.0.2.0).
Another issue is that the connection pool implementation bundled with the Oracle JDBC driver is deprecated, so UCP is the only option to go with in the long run.
Could someone help me to clarify the licence and release strategy for UCP?
Thanks,
Ulf

You can either require a customer to download it themselves or perhaps even automate the download as part of your install.
Other than that I can only mention that my expectation is that you will not get an answer from Oracle (a rep) unless you have a monetary relationship with them. If you have a good customer that has purchased an Oracle license they might be able to ask for you via their support license.

JDBC connection pools problems: weblogic doesn't release connections

Hi all,
we use Weblogic 5.1 in conjunction with Content Server 3.6 and Oracle
8.1.6;
We have this strange problem:
Calling a page the connections, in the content server connection pool,
grows up till the maximum. We think the problem is that Weblogic
doesn't release used connections.
Does anybody can help us? Did anybody had the same problem?
Best Regards,
Marcello Villani

Hi. I'd have to see the code. When a pool connection is closed, it gets
back into the pool. Until it's closed, it doesn't.
Marcello Villani wrote:
Hi all,
we use Weblogic 5.1 in conjunction with Content Server 3.6 and Oracle
8.1.6;
We have this strange problem:
Calling a page the connections, in the content server connection pool,
grows up till the maximum. We think the problem is that Weblogic
doesn't release used connections.
Does anybody can help us? Did anybody had the same problem?
Best Regards,
Marcello Villani

Connection pooling & multiple apps in single instance - many sessions

Any feedback would be much appreciated from anyone with experience already with this situation and/or can provide some insight on this:
Adhering to the trend of consolidating instances, we have a single consolidated instance with multiple apps. With connection pooling (we use apache & mod_perl), I suppose you have an option of creating some oracle db accounts that can be shared among multiple apps - that benefits you in reducing the numbers of total pooled db connections to the instance - but one very big drawback is that you have some apps, if sharing generic db userids, having access to tables they have no need to access.
On another hand, you have the option (which is the approach we've taken thus far and, in my view, is definitely the way to go) of a distinct oracle account for each app - on the downside, that could produce many more total db sessions (& os processes) on the server as each new set of unique persistent pooled connections are created - but it benefits you in terms of security - which has a lot of weight - since each app account only has access to what it needs & nothing beyond that (the "least privilege" concept).
We're not an "amazon.com" so we haven't had to deal with thousands of sessions within an instance so there's an element of the unknown here for us - some questions I have are: How can I accurately predict how many db sessions (& os processes) this particular solaris server can support? I realize kernel parameters need to be set high enough for this sort of environment but simply setting the parameters cannot be a true indication of what the server can support. How much memory is required for thousands of sessions? I'm trying to gauge how many sessions & processes we can currently support - and at what point we'll need additional memory, or an updated server, or at what point we need to start thinking about an additional server environment for new apps.
I realize connection pooling is, by it nature, reducing the overall sessions required but as each unique db account is created, there will be set of persistent sessions out there and that will grow.
Also if you have any insight on other things to think about when heading into the direction of lots of sessions (beyond kernel settings, other OS or db parameters that need to be reviewed, or some features to enable).
I'm rambling so I'll stop right there; sorry about the length of the post. It's possible that the things to look at and consider are pretty straight-forward.
Thanks in advance for any feedback on any of the above.
-Rick Papaj
[email protected]

You better check the documentation available on OTN
http://download-west.oracle.com/docs/cd/B25221_03/web.1013/b14432/threadpool.htm
There are several options you can setup with pooling.
hope this helps.

RFC_FAILURE affects Connection Pool

Using VB.NET (2003) with .Net Connector 2.0.
An intermittent problem causes a RFC Call to fail, and an exception is raised in the .NET code. The Exception message is:
 See RFC trace file or SAP system log for more details
The Trace file shows:
ERROR file opened at 20051115 131423 GMT Standard
 T, SAP-REL 640,0,78 RFC-VER 3 759904 MT-SL
T:2844 Could not send rfc container 0x130
T:2844 <* RfcCall [1] : returns 1:RFC_FAILURE
T:2844 <* RfcCallReceive [1] : returns 1:RFC_FAILURE
>TS> Tue Nov 15 13:14:24 2005
T:2844 <* RfcCleanupContext [1] : returns
 18:RFC_INVALID_HANDLE
T:2844 <* RfcCleanupContext [1] : returns
 18:RFC_INVALID_HANDLE
This error adversely affects the Connection Pool as calls to other RFCs are now prone to similar intermittent errors
Is there any way to prevent the problem causing problems with Connection Pool ?
Is there any way of removing a faulty connection from the pool ? (NB Close and Dispose on the connection does not help)

The application is a Windows service - so I don't want to lose any connections. I assume that closing the connection (and not returning it) will affect the number of available connections in the pool(?).
I'm using async. RFC call, and the problem is detected in the callback function when the EndRFCCall is performed.
Original code:
Public Sub Execute_RFC(ByVal parameters as string())
' Assign SAP Connection to RFC Proxy
sapRFCProxy.Connection = SAPConnectionPool.GetConnectionFromPool(ConnectString)
Call the SAP RFC - Asynchronously
arAsyncResult = m_sapRFCProxy.BeginRFCCall( params..., AddressOf RFC_CallBack, objAsyncState)
End Sub
Private Sub RFC_CallBack(ByVal ar As IAsyncResult)
Try
 ' Retrieve the SAP RFC Response...
 Call sapRFCProxy.EndRFCCall(ar, param1, param2, etc...)
Catch ex As Exception
 ' Log the Error...
End Try
' Return the Connection
Call SAPConnections.ReturnConnection(sapRFCProxy.Connection)
End Sub
I have changed the code as suggest so that the connection is closed, disposed but not returned. This cleared the RFC_INVALID_HANDLE errors, but the main problem of a corrupted connection persists.
Diagnostics produced by the amended code:
Trace File (Info):
2005-11-16 11:55:46Z Warning: RfcCleanupContext failed. Closing connection
dev_RFC.trc
ERROR file opened at 20051116 115546 GMT Standard T, SAP-REL 640,0,78 RFC-VER 3 759904 MT-SL
T:3068 ======> CPIC-CALL: 'CMSEND'
ERROR program state check for conversation 99610798
TIME Wed Nov 16 11:55:46 2005
RELEASE 640
COMPONENT CPIC (TCP/IP)
VERSION 3
RC 471
MODULE r3cpic.c
LINE 2576
DETAIL called function STSEND in state state=BUFFER_DATA2
COUNTER 1
T:3068 <* RfcCall [20] : returns 1:RFC_FAILURE
T:3068 <* RfcCallReceive [20] : returns 1:RFC_FAILURE
T:3068 <* RfcCleanupContext [20] : returns 1:RFC_FAILURE
Even with the change to the code, a call to a reliable RFC will now fail intermittently with:
T:2876 Could not send rfc container 0x130
T:2876 <* RfcCall [24] : returns 1:RFC_FAILURE
T:2876 <* RfcCallReceive [24] : returns 1:RFC_FAILURE
Thanks

Issues with JDBC Connection Pooling

Hi all,
I'm experiencing some unexpected behaviour when trying to use JDBC Connection Pooling with my BC4J applications.
The configuraiton is -
Web Application using BC4J in local mode
Using Default Connection Stagegy
Stateless Release Mode
Retrieving Application Modules using Configuration.createRootApplicationModule( am , cf );
Returning Application Modules using Configuration.releaseRootApplicationModule( am, false );
Three application modules
AppModuleA - connects to DatabaseConnection1
AppModuleB - connects to DatabaseConnection2
AppModuleC - connects to DatabaseConnection2
My requirement is to -
Use App Module Pooling and have individual pool for each Application Module
Use JDBC Pooling and have individual pool for each Database connection
Note: All configuration was achieved in design mode (i.e. right clicking AppModule->Configurations...)
1. Initial approach -
In the configuration for each Application Module I specified the connection type as 'JDBC Datasource' and specified to approriate datasource.
Tried setting doConnecitonPooling to 'true' as well as 'false'
In the data-sources.xml I specified all the appropriate info including min-connections and max-connections.
I would expect, with the above config that BC4J would use OC4J's built in JDBC connection pooling.
2. Second approach -
In the configuration for each Application Module I specified the connection type as JDBC URL.
In the configuration I specified doConnectionPooling = 'true' as well as the max connection, max available and min available
What I experienced in both cases was that the max connections seem to be ignored as the number of connection as reported by the database (v$session) was exceeded by more than 10.
In addition to this once the load was removed the number of JDBC connecitons did not drop (I would have expected it to drop to max available connections)
My questions are -
1. When specifying to use a 'JDBC Datasource' style of connection, is it in fact OC4J that is then responsible for pooling JDBC connections? And in this case should BC4J's doConnectionPooling parameter be set to true or false?
2. Are there any known issues with the use of the JDBC Conneciton Pool as stated by the above to approaches?

Thanks for the additional info. Please see my comments. below.
Sorry should have been more specififc -
1. Is each application pool using a different JDBC user? You mentioned DatabaseConnection1 and DatabaseConnection2
above; are these connections to different schemas / users? If so, BC4J will create a separate connection pool for each
JDBC user. Each connection pool will have its own maximum pool size.
Each 'DatabaseConnection' refers to a different database, actually hosted on a seperate physical server, different
schema and different user.BC4J will maintain a separate connection pool for each permutation of JDBC URL / schema. If each user is connecting
to a different DB instance then I would expect no greater than 10 DB sessions. However, if a DB instance is hosting
more than user then I would expect greater than 10 DB sessions (though still no more than 10 DB sessions per user).
2. Are all the v$session sessions related to the JDBC clients? There should be at least one additional database
session which will be related to the session that is querying v$session.
When querying the v$session table I specifically look for connections from the user in quesiton and from the machine
name in question and in doing so eliminate the database system's connections, as well as the query tools'
connection. One area I'm not sure about is the connection BC4J uses to write to its temporary tables. I am using
Stateless release mode and have not explicetly stated to save to the database but I'm wondering if it still does if so
and how does it come into the equation with max connections?BC4J's internal connections are also pooled and the limits apply as mentioned above. So, if you have specified
internal connection info for a schema which is different than the users above I would expect the additional conns.
One helpful diagnostic tool, albeit programmatic, might be to print the information about the connection pools after
your test client(s) have finished. This may be accomplished as follows:
// get a reference to the BC4J connection pool manager
import oracle.jbo.server.ConnectionPoolManagerFactory;
import oracle.jbo.server.ConnectionPoolManagerImpl;
import oracle.jbo.pool.ResourcePool;
import java.io.PrintWriter;
import java.util.Enumeration;
// get the ConnectionPoolManager. assume that it is an instance of the supplied manager
ConnectionPoolManagerImpl mgr = (ConnectionPoolManagerImpl)ConnectionPoolManagerFactory.getConnectionPoolManager();
Enumeration keys = mgr.getResourcePoolKeys();
PrintWriter pw = new PrintWriter(System.out, true);
while (keys.hasMoreElements())
Object key = keys.nextElement();
ResourcePool pool = (ResourcePool)mgr.getResourcePool(key);
System.out.println("Dumping pool statistics for pool: " + key);
pool.dumpPoolStatistics(pw);
}

SAP JCo3 connection pool instance release

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