Grails maxRows/queryTimeout warning - grails

Question

I seem to randomly get the warning below in my Grails 2.2.4 application. It doesn't look like it is causing any issues, but it is still concerning.
I tried to prevent this warning by modifying my datasource properties in my DataSource.groovy file:
dataSource {
pooled = true
properties {
maxWait = 10000 // 10 seconds
minEvictableIdleTimeMillis = 1000 * 60 * 30 // 30 minutes
numTestsPerEvictionRun = 3
testOnBorrow = true
testOnReturn = false
testWhileIdle = false
timeBetweenEvictionRunsMillis = 1000 * 60 * 30 // 30 minutes
validationQuery = "SELECT 1"
}
}
And when that didn't work I tried to set the properties in my BootStrap.groovy file:
def init = { servletContext ->
def ctx = Holders.getApplicationContext()
def dataSource = ctx.dataSourceUnproxied
println "configuring database connection pool"
dataSource.setMinEvictableIdleTimeMillis(1000 * 60 * 30)
dataSource.setTimeBetweenEvictionRunsMillis(1000 * 60 * 30)
dataSource.setNumTestsPerEvictionRun(3)
dataSource.setTestOnBorrow(true)
dataSource.setTestWhileIdle(false)
dataSource.setTestOnReturn(false)
dataSource.setValidationQuery("SELECT 1")
}
Neither attempt prevents the warning. The author of this post said he had success setting the properties directly in the tomcat config, but I need a more generic solution that will work from the command line and in other servers.
2013-09-25 15:07:51,027 [http-bio-8080-exec-9] WARN jdbc.AbstractBatcher - exception clearing maxRows/queryTimeout
java.sql.SQLException: org.apache.commons.dbcp.DelegatingPreparedStatement with address: "com.mysql.jdbc.JDBC4PreparedStatement#13ed0db0: EXCEPTION: com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: No operations allowed after statement closed." is closed.
at org.apache.commons.dbcp.DelegatingStatement.checkOpen(DelegatingStatement.java:137)
at org.apache.commons.dbcp.DelegatingStatement.getMaxRows(DelegatingStatement.java:237)
at ace_2.DefsUploadController.upload(DefsUploadController.groovy:16)
at grails.plugin.cache.web.filter.PageFragmentCachingFilter.doFilter(PageFragmentCachingFilter.java:195)
at grails.plugin.cache.web.filter.AbstractFilter.doFilter(AbstractFilter.java:63)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at java.lang.Thread.run(Thread.java:724)

Answer 1

After connections to my MySQL database timed out I would see that exact exception as well. I updated the DataSource configuration using the suggestion in the Grails docs as a guideline and I have yet to see any exceptions from closed connections.
Here are my current settings:
properties {
initialSize=5
maxActive=50
minIdle=5
maxIdle=25
maxWait = 10000
maxAge = 10 * 60000
timeBetweenEvictionRunsMillis = 5000
minEvictableIdleTimeMillis = 60000
validationQuery = "SELECT 1"
validationQueryTimeout = 3
validationInterval = 15000
testOnBorrow = true
testWhileIdle = true
testOnReturn = false
jdbcInterceptors = "ConnectionState;StatementCache(max=200)"
defaultTransactionIsolation = java.sql.Connection.TRANSACTION_READ_COMMITTED
}