Configuration values set in system properties. Setting this to true may lead to subtle and bizarre bugs. For examples, see the built-in implementations in c3p0’s source code. Each PooledDataSource within your application may have the following attributes embedded within its ObjectName: Previously, c3p0 was happy for generated IDs to be unique within a single VM and it didn’t even get that quite right, before c3p

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For the target, and for any of the method arguments, you can supply the special token C3P0ProxyConnection. See Appendix A for details. For some applications, high performance is more important than the risk of an occasional database exception. Note that if a database restart occurs, a pool may contain previously acquired but now stale Connections.

How to use the C3P0 JDBC connection pool in your Maven Project.

If jdb are using named configurationsyou can specify the configuration that defines the default configuration for your DataSource:. If you would the test to timeout and fail, set the following key. Performing the expensive default Connection test on every client checkout will harm client performance.

If a table-independent query is not sufficient, instead of preferredTestQueryyou can set the parameter automaticTestTable. By clicking “Post Your Answer”, you acknowledge that you have read our updated terms of serviceprivacy policy and cookie policyand that your continued use of the website is subject to these policies. Use in combination with idleConnectionTestPeriod for quite reliable, always asynchronous Connection testing.


c3p0-v – JDBC3 Connection and Statement Pooling – Documentation

Many of c3p0’s functions are not performed by client threads, but asynchronously by an internal thread pool.

Properties files called c3p0. Sign up using Facebook. Unless you are supplying your own unpooled DataSource, a must always be provided and appropriate for the JDBC driver, however it is resolved. Regardless of acquireIncrementthe pool will never allow maxPoolSize to be exceeded.

If tasks are hanging forever, try to figure out why, and maybe setting maxAdministrativeTaskTime can help in the meantime. Synchronous check-ins are likely to improve overall performance when c3poo is set to false and no slow work is performed djbc a ConnectionCustomizer ‘s onCheckIn It will work even with very old JDBC drivers.

Begin by setting testConnectionOnCheckout to true and get your application to run correctly and stably. Normally, c3p0’s configuration information is placed in a either a c3p0-config. The size of c3p0’s global PreparedStatement cache. C3P0 offers a wide variety of options for controlling how quickly pools that have grown large under load revert to minPoolSizeand whether “old” Connections in the pool should be proactively replaced to maintain their reliablity.

Setting the parameter driverClass causes that class to preload and register with java. Regardless of how you create your DataSource, c3p0 will use defaults for any configuration parameters that you do not specify programmatically.


As well as Connection pool realted statistics, you can retrieve c3p information about each DataSource’s Thread pool. 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. 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?

AccessControlContext associated with c3p0 library classes. You should not work with the named table after c3p0 creates it; it should be strictly for c3p0’s use in testing your Connection.

If you wish to use a named configuration, construct your com. There’s no need to implement your own ConnectionCustomizer if you just want initSql.

However, asynchronous checkins add to Thread pool congestion. If maxStatements is zero but maxStatementsPerConnection is a non-zero value, statement caching will be enabled, but no global limit will be enforced, only the per-connection maximum.

Determines how the contextClassLoader see java. For the moment, distributed c3p0 binaries are compiled with debug set to true and trace set to its maximum level of