fixed java.lang.OutOfMemoryError: unable to create new native thread

for tests

pom.xml

@@ -226,6 +226,7 @@
 				<groupId>org.apache.maven.plugins</groupId>
 				<artifactId>maven-surefire-plugin</artifactId>
 				<configuration>
+			    	<argLine>-Xmx2048m -XX:MaxPermSize=512m</argLine>
 					<parallel>methods</parallel>
 					<threadCount>10</threadCount>
 					<useFile>false</useFile>
@@ -245,6 +246,7 @@
 				<groupId>org.apache.maven.plugins</groupId>
 				<artifactId>maven-failsafe-plugin</artifactId>
 				<configuration>
+				    <argLine>-Xmx2048m -XX:MaxPermSize=512m</argLine>
 					<useFile>false</useFile>
 					<includes>
 						<include>**/test/integration/**/*.java</include>

spring-cassandra/src/test/java/org/springframework/cassandra/test/integration/AbstractEmbeddedCassandraIntegrationTest.java

@@ -29,7 +29,7 @@ public abstract class AbstractEmbeddedCassandraIntegrationTest {
 	/**
 	 * Whether to clear the cluster before the next test.
 	 */
-	protected boolean clear = true;
+	protected boolean clear = false;
 	/**
 	 * Whether to connect to Cassandra.
 	 */