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copied!<p>You have the c3p0 parameter checkoutTimeout set, and you are either exhausting your pools via a Connection leak, or you are just pushing them very hard, so that some clients fail to acquire a Connection within the checkoutTimeout period.</p> <p>Ways to deal:</p> <p>1) Make sure you aren't leaking Connections. try setting unreturnedConnectionTimeout and debugUnreturnedConnectionStackTraces (see <a href="http://www.mchange.com/projects/c3p0/#configuring_to_debug_and_workaround_broken_clients" rel="nofollow">here</a>)</p> <p>2) If there is no Connection leak, configure your DataSource better so that it can deal with your load. First, try increasing <a href="http://www.mchange.com/projects/c3p0/#numHelperThreads" rel="nofollow">numHelperThreads</a>, make significantly bigger than the number of cores on which you are running (since these Threads are often held up on IO with the database). Next, try a larger maxPoolSize. You might also reconfigure statement pooling. For simplicity, I'd turn it off until you resolve this issue (set maxStatements to zero). When Connection pooling is working well, you can turn it back on, but Statements of 100 is way to few to handle 200-ish Connections, you'll unproductively churn through PreparedStatements. Consider using <a href="http://www.mchange.com/projects/c3p0/#maxStatementsPerConnection" rel="nofollow">maxStatementsPerConnection</a> instead of maxStatements. Set its value to about the number of PreparedStatements frequently used by application clients.</p> <p>3) If your DataSource still can't promptly handle the load, accept a longer <a href="http://www.mchange.com/projects/c3p0/#checkoutTimeout" rel="nofollow">checkoutTimeout</a> (or set checkoutTimeout to zero so that clients never time out).</p> <p>Unrelatedly... are you sure you want <a href="http://www.mchange.com/projects/c3p0/#autoCommitOnClose" rel="nofollow">autoCommitOnClose</a> set to true?</p> <p>Good luck!</p>

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