Re: Cannot get a connection, pool exhausted
Simple question - are there more than 100 requests active when this happens?
Larry
On 4/21/07, [EMAIL PROTECTED] <[EMAIL PROTECTED]> wrote:
Now instead of set connection static i just create a new one for each query to
perform, so if there are concurrent queries it shouldn't cause any problem:
private Connection getConnection() throws Exception {
// get context: provides the starting point for resolution of names
Context ctx = new InitialContext();
if (ctx == null) {
throw new Exception("No Context");
}
// retrieve datasource
DataSource ds = (DataSource) ctx.lookup("java:comp/env/jdbc/xxDB");
if (ds == null) {
throw new Exception("No Datasource");
}
// return db connection
return ds.getConnection();
}
public void doSomething() {
Connection con = null;
Statement stmt = null;
try {
// get connection
con = getConnection();
if (con == null) {
throw new Exception("No Connection");
}
stmt = con.createStatement();
stmt.executeUpdate("UPDATE yy SET `zz`=0 WHERE `ww`='oo'");
}
catch (Exception e1) {
//
}
// close resources
finally {
try {
stmt.close();
stmt = null;
}
catch (Exception e2) {
//
}
try {
con.close();
con = null;
}
catch (Exception e3) {
//
}
}
}
is there anything else i should change for getting the pool connection to work?
Thanks in advance.
-- Initial Header ---
From : "[EMAIL PROTECTED]" [EMAIL PROTECTED]
To : "users" users@tomcat.apache.org
Cc :
Date : Sat, 21 Apr 2007 10:08:21 +0200
Subject : Cannot get a connection, pool exhausted
> Hello,
> i'm trying to achieve DBCP with tomcat 5.5.9. I thought to have done things right since
the application could connect to db, but after a night that the application was running, in
the morning, in logs, i saw a lot of "Cannot get a connection, pool exhausted"
errors.
> This is my configuration:
>
> SERVER.XML:
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
> CONTEXT.XML:
>
>
>name="jdbc/xxDB"
> auth="Container"
> type="javax.sql.DataSource"
> maxActive="100"
> maxIdle="30"
> maxWait="1"
> username="user"
> password="pass"
> driverClassName="com.mysql.jdbc.Driver"
> url="jdbc:mysql://127.0.0.1:3306/xx_xx?autoReconnect=true"/>
>
>
> WEB.XML:
>
>
>
> http://java.sun.com/xml/ns/j2ee";
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"; xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee
http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd"; version="2.4">
> xx
>
> xxx.ApplicationWatch
>
>
> htmlcontent
> xxx.HtmlContentServlet
>
>
> htmlcontent
> /htmlcontent.view
>
>
> DB Connection
> jdbc/xxDB
> javax.sql.DataSource
> Container
>
>
> Security Constraint
>
> Protected Area
> /*
>
>
> xx
>
>
>
> BASIC
> Protected Area
>
>
> xx
>
>
>
> THE WAY I CONNECT TO DB (this is one of the 6-7 methods i have to do stuff on
db):
>
> private static Connection con = null;
>
> private static Connection getConnection() throws Exception {
> // get context: provides the starting point for resolution of names
> Context ctx = new InitialContext();
> if (ctx == null) {
> throw new Exception("No Context");
> }
> // retrieve datasource
> DataSource ds = (DataSource) ctx.lookup("java:comp/env/jdbc/xxDB");
> if (ds == null) {
> throw new Exception("No Datasource");
> }
> // return db connection
> return ds.getConnection();
> }
>
> public static void doSomething() {
> Statement stmt = null;
> try {
> // get connection
> con = getConnection();
> if (con == null) {
> throw new Exception("No Connection");
> }
> stmt = con.createStatement();
> stmt.executeUpdate("UPDATE yy SET `zz`=0 WHERE `ww`='oo'");
> }
> catch (Exception e1) {
> //
> }
> // close resources
> finally {
> try {
> stmt.close();
> stmt = null;
> }
> catch (SQLException e2) {
> //
> }
> try {
> con.close();
> con = null;
> }
> catch (SQLException e3) {
> //
> }
> }
> }
>
> Anybody have a clue of what can be? any help appreciated.
>
>
>
> --
> Passa a Infostrada. ADSL e Telefono senza limiti e senza canone Telecom
> http://click.libero.it/infostrada
>
>
>
> -
> To start a new topic, e-mail: users@tomcat.apache.org
> To unsubscribe, e-mail: [EMAIL PROTECTED]
> For additional commands, e-mail: [EMAIL PROTECTE
Re: Cannot get a connection, pool exhausted
What you have below looks good as far as I can tell. Connections appear
to be returned ASAP after using them. Do all your calls to the database
follow this pattern? Are there any places where the connection isn't
closed immediately and within a finally block?
As an aside, you can store the DataSource object once you've done the
JNDI look-up for the first time. That won't harm anything and might
improve speed a little.
--David
[EMAIL PROTECTED] wrote:
Now instead of set connection static i just create a new one for each query to
perform, so if there are concurrent queries it shouldn't cause any problem:
private Connection getConnection() throws Exception {
// get context: provides the starting point for resolution of names
Context ctx = new InitialContext();
if (ctx == null) {
throw new Exception("No Context");
}
// retrieve datasource
DataSource ds = (DataSource) ctx.lookup("java:comp/env/jdbc/xxDB");
if (ds == null) {
throw new Exception("No Datasource");
}
// return db connection
return ds.getConnection();
}
public void doSomething() {
Connection con = null;
Statement stmt = null;
try {
// get connection
con = getConnection();
if (con == null) {
throw new Exception("No Connection");
}
stmt = con.createStatement();
stmt.executeUpdate("UPDATE yy SET `zz`=0 WHERE `ww`='oo'");
}
catch (Exception e1) {
//
}
// close resources
finally {
try {
stmt.close();
stmt = null;
}
catch (Exception e2) {
//
}
try {
con.close();
con = null;
}
catch (Exception e3) {
//
}
}
}
is there anything else i should change for getting the pool connection to work?
Thanks in advance.
-- Initial Header ---
From : "[EMAIL PROTECTED]" [EMAIL PROTECTED]
To : "users" users@tomcat.apache.org
Cc :
Date : Sat, 21 Apr 2007 10:08:21 +0200
Subject : Cannot get a connection, pool exhausted
Hello,
i'm trying to achieve DBCP with tomcat 5.5.9. I thought to have done things right since
the application could connect to db, but after a night that the application was running,
in the morning, in logs, i saw a lot of "Cannot get a connection, pool
exhausted" errors.
This is my configuration:
SERVER.XML:
CONTEXT.XML:
WEB.XML:
http://java.sun.com/xml/ns/j2ee"; xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance";
xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd";
version="2.4">
xx
xxx.ApplicationWatch
htmlcontent
xxx.HtmlContentServlet
htmlcontent
/htmlcontent.view
DB Connection
jdbc/xxDB
javax.sql.DataSource
Container
Security Constraint
Protected Area
/*
xx
BASIC
Protected Area
xx
THE WAY I CONNECT TO DB (this is one of the 6-7 methods i have to do stuff on
db):
private static Connection con = null;
private static Connection getConnection() throws Exception {
// get context: provides the starting point for resolution of names
Context ctx = new InitialContext();
if (ctx == null) {
throw new Exception("No Context");
}
// retrieve datasource
DataSource ds = (DataSource) ctx.lookup("java:comp/env/jdbc/xxDB");
if (ds == null) {
throw new Exception("No Datasource");
}
// return db connection
return ds.getConnection();
}
public static void doSomething() {
Statement stmt = null;
try {
// get connection
con = getConnection();
if (con == null) {
throw new Exception("No Connection");
}
stmt = con.createStatement();
stmt.executeUpdate("UPDATE yy SET `zz`=0 WHERE `ww`='oo'");
}
catch (Exception e1) {
//
}
// close resources
finally {
try {
stmt.close();
stmt = null;
}
catch (SQLException e2) {
//
}
try {
con.close();
con = null;
}
catch (SQLException e3) {
//
}
}
}
Anybody have a clue of what can be? any help appreciated.
--
Passa a Infostrada. ADSL e Telefono senza limiti e senza canone Telecom
http://click.libero.it/infostrada
-
To start a new topic, e-mail: users@tomcat.apache.org
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, e-mail: [EMAIL PROTECTED]
--
Passa a Infostrada. ADSL e Telefono senza limiti e senza canone Telecom
http://click.libero.it/infostrada
-
To start a new topic, e-mail: users@tomcat.apache.org
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional command
Re: Cannot get a connection, pool exhausted
On 4/21/07, [EMAIL PROTECTED] <[EMAIL PROTECTED]> wrote: is there anything else i should change for getting the pool connection to work? Thanks in advance. Most of the best practices and common mistakes to avoid are covered here: http://tomcat.apache.org/tomcat-5.0-doc/jndi-datasource-examples-howto.html IMO, especially under: Random Connection Closed Exceptions Also this http://jakarta.apache.org/commons/dbcp/configuration.html provides additional documentation on the various parameters. -Rashmi - To start a new topic, e-mail: users@tomcat.apache.org To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
