Last acquisition attempt excepti on: If database restarts will be rare so quick recovery is not an issue, consider reducing the frequency of tests by idleConnectionTestPeriod to, say, , and see whether clients are troubled by stale or broken Connections. When you instantiate a c3p0 PooledDataSource , whether via the ComboPooledDataSource constructor or via the DataSources factory class, you can supply a configuration name. To override the library’s built-in defaults, create a file called c3p0. Synchronous check-ins are likely to improve overall performance when testConnectionOnCheckin is set to false and no slow work is performed in a ConnectionCustomizer ‘s onCheckIn It’s rarely worth spending time in pursuit of “optimal” values here.
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User configuration is stored as a Map containing String keys and values, stored under the following configuration parameter:. C3P0 does provide an API that allows you to invoke non-standard methods reflectively on an underlying Connection.
To install a ConnectionCustomizer just implement the interface, make your class accessible to c3p0’s ClassLoader, and set the configuration parameter below:. Connections could not be acquired from the underlying database! The extensions Map can be set programatically like any other configuration parameter. If all attempts fail, any clients waiting for Connections from the DataSource will see an Exception, indicating that a Connection could not be acquired. Setting forceIgnoreUnresolvedTransactions is strongly discouraged, because if clients are not careful to commit or rollback themselves prior to closeor do not set Connection autoCommit consistently, bizarre unreproduceable behavior and database lockups can occur.
Third-party DataSource implementations can be substituted for c3p0’s DriverManagerDataSource with no significant loss of functionality.
The identityToken is a unique String associated with each c3p0 DataSource. Thu Jan 03, 1: Otherwise setting this to true is just a bad idea. The environment is basically the same. You can easily configure Apache’s Tomcat web application server to use c3p0 pooled DataSources.
This “issue” will not be changed or fixed.
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C3P0 used to use reflective, dynamic proxies. Below is a sample ConnectionCustomizer. Thread of c3p0-spawned Threads is determined. To override suitagle library’s built-in defaults, create a file called c3p0.
ResourceBundle if this is unfamiliar. Consider setting testConnectionOnCheckin back to false to avoid unnecessary tests on checkin. In a properties-style config file Determines how many connections at a time c3p0 will try to acquire when the pool is exhausted. See the box below.
What can we do to improve this information or fewer characters. Coordinates of this version on the Maven central repository: Email Required, but never shown. Enhanced performance is the purpose of Connection and Statement pooling, and a major goal of the c3p0 library.
The best thing to do is usually to try Step 3, see if it helps however you measure performancesee if it hurts is your application troubled by broken Connections?
classpath issue with c3p0 (Tomcat forum at Coderanch)
See ” Configuring Connection Testing “. If both parameters are greater than zero, both limits will be enforced.
If that Thread came from a client that may sultable to be hot-undeployed, references to these objects may prevent the undeployed application, often partitioned into a ClassLoaderfrom being garbage collected. Otherwise, the pool will occasionally kill Connections in active use, which is bad. If false, failure to obtain a Connection will cause all Threads waiting for the pool to acquire a Connection to throw an Exception, but the DataSource will remain valid, and will attempt to acquire again following a call to getConnection.
I tried nl into netbeans but it wasn’t too happy with it.
If users have set autoCommit to false on a Connection, and c3p0 cannot guarantee that there is no pending transactional work, c3p0 must either rollback or commit on check-in when a user calls close. If callerc3p0-spawned Threads helper threadsjava.