JPA tests hang while obtaining HSQL connection from Maven Command Line - spring

Question

Tests work individually within Eclipse (right click, run as Junit), but when I run them from the command line with maven, it stops while trying to obtain a DataSource connection to the HSQL database.
LogicalConnectionImpl [DEBUG] Obtaining JDBC connection
The oddest part to me is that if I limit the tests being run to 10 (not classes, but individual #Test methods), it will work. But once that 11th test is run it bombs out. The test combinations do not matter, so if I have 30 tests, and I choose 11 or more to run, then it will fail. This made me think it is a DataSource connection max issue, but so far no luck with details of that. I have tried adding heap size just for giggles, but that did not work.
So prior to this hang, I have multiple successful JDBC connection and releases.
Here is my applicationContext-HSQL.xml, which is used for both the in Eclipse and Command Line versions. I know b/c I have forced each of them to fail by messing with the Class values below.
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:aop="http://www.springframework.org/schema/aop"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:flow="http://www.springframework.org/schema/webflow-config"
xmlns:lang="http://www.springframework.org/schema/lang"
xmlns:osgi="http://www.springframework.org/schema/osgi"
xmlns:tx="http://www.springframework.org/schema/tx"
xmlns:util="http://www.springframework.org/schema/util"
xmlns:p="http://www.springframework.org/schema/p"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.0.xsd
http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd
http://www.springframework.org/schema/webflow-config http://www.springframework.org/schema/webflow-config/spring-webflow-config-2.0.xsd
http://www.springframework.org/schema/lang http://www.springframework.org/schema/lang/spring-lang-3.0.xsd
http://www.springframework.org/schema/osgi http://www.springframework.org/schema/osgi/spring-osgi-3.0.xsd
http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.0.xsd
http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-3.0.xsd">
<context:annotation-config/>
<context:component-scan base-package="com.company"/>
<import resource="classpath*:/application-context-cxf.xml"/>
<bean id="entityManagerFactory" class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
<property name="dataSource" ref="dataSource" />
<property name="persistenceXmlLocation" value="META-INF/persistence.xml" />
<property name="jpaVendorAdapter">
<bean class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter">
<property name="showSql" value="false" />
<property name="generateDdl" value="false" />
<property name="databasePlatform" value="org.hibernate.dialect.HSQLDialect" />
</bean>
</property>
</bean>
<bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close">
<property name="driverClassName" value="org.hsqldb.jdbcDriver" />
<property name="url" value="jdbc:hsqldb:mem:test" />
<property name="username" value="sa" />
<property name="password" value="" />
</bean>
<tx:annotation-driven />
<bean id="transactionManager" class="org.springframework.orm.jpa.JpaTransactionManager" >
<property name="entityManagerFactory" ref="entityManagerFactory" />
</bean>
</beans>
All of my Test classes utilize Spring 3.2.5, JPA, DBUnit and extend AbstractInMemoryTests.java
#RunWith(SpringJUnit4ClassRunner.class)
#ContextConfiguration(locations={"classpath:applicationContext-hsqldb.xml"})
public class AbstractInMemoryTests {
private static final String FLAT_XML_DATASET = "FlatXmlDataSet.xml";
#Autowired
BasicDataSource bds;
#Before
public void setUp() throws Exception {
DatabaseOperation.CLEAN_INSERT.execute(getConnection(), getDataSet());
}
#SuppressWarnings("deprecation")
private IDataSet getDataSet() throws Exception {
InputStream inputStream = this.getClass().getClassLoader().getResourceAsStream(FLAT_XML_DATASET);
IDataSet dataset = new FlatXmlDataSet(inputStream);
return dataset;
}
private IDatabaseConnection getConnection() throws Exception {
Connection jdbcConnection = bds.getConnection();
IDatabaseConnection connection = new DatabaseConnection(jdbcConnection);
return connection;
}
}
Any ideas on why I may be hanging on that connection, or an idea of how to troubleshoot?
Thanks,
Sean

Answer 1

Per the usual protocol, a good nights sleep helps you think. I completely over-looked the maxActive setting available for the appContext-hsqldb.xml property for my DataSource
<bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close">
<property name="driverClassName" value="org.hsqldb.jdbcDriver" />
<property name="url" value="jdbc:hsqldb:mem:test" />
<property name="username" value="sa" />
<property name="password" value="" />
****<property name="maxActive" value="-1"/>****
</bean>
Hope this helps someone else in the future.
http://commons.apache.org/dbcp/apidocs/org/apache/commons/dbcp/BasicDataSource.html

Answer 2

if something is hanging you can use "kill -3 {process_number}" on Unix and it gives a thread dump (if not on Unix there is an equivalent on Windows/Mac). That will show where the lock problem is, which may give you an idea what causes it and how to fix it

Answer 3

If the hanging comes after few page access, (maybe 8 which is the default maxTotal), you are not never closing the connection and opening in every request.
Just use entityManager.close(); after the db queries or check if the a connection already exists before creating a new one.
The accepted answer is setting the maxTotal connections to unlimited. Connections will just keep pilling up.