Bug 55518 - Add ability to limit number of cached PreparedStatements per connection when "Prepared Select Statement", "Prepared Update Statement" or "Callable Statement" query type is selected

Bugzilla Id: 55518

git-svn-id: https://svn.apache.org/repos/asf/jmeter/trunk@1520926 13f79535-47bb-0310-9956-ffa450edef68

Former-commit-id: d1b40b8228

bin/jmeter.properties

@@ -635,6 +635,16 @@ wmlParser.types=text/vnd.wap.wml
 # To set the Monitor Health Visualiser buffer size, enter the desired value
 # monitor.buffer.size=800
 
+#---------------------------------------------------------------------------
+# JDBC Request configuration
+#---------------------------------------------------------------------------
+
+# Max number of PreparedStatements per Connection for PreparedStatement cache
+#jdbcsampler.maxopenpreparedstatements=100
+
+# String used to indicate a null value
+#jdbcsampler.nullmarker=]NULL[
+
 #---------------------------------------------------------------------------
 # OS Process Sampler configuration
 #---------------------------------------------------------------------------

src/protocol/jdbc/org/apache/jmeter/protocol/jdbc/AbstractJDBCTestElement.java

@@ -30,6 +30,7 @@ import java.sql.SQLException;
 import java.sql.Statement;
 import java.util.ArrayList;
 import java.util.Collection;
+import java.util.Collections;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
@@ -61,6 +62,9 @@ public abstract class AbstractJDBCTestElement extends AbstractTestElement implem
     // String used to indicate a null value
     private static final String NULL_MARKER =
         JMeterUtils.getPropDefault("jdbcsampler.nullmarker","]NULL["); // $NON-NLS-1$
+    
+    private static final int MAX_OPEN_PREPARED_STATEMENTS =
+        JMeterUtils.getPropDefault("jdbcsampler.maxopenpreparedstatements", 100); 
 
     private static final String INOUT = "INOUT"; // $NON-NLS-1$
 
@@ -323,7 +327,15 @@ public abstract class AbstractJDBCTestElement extends AbstractTestElement implem
     private PreparedStatement getPreparedStatement(Connection conn, boolean callable) throws SQLException {
         Map<String, PreparedStatement> preparedStatementMap = perConnCache.get(conn);
         if (null == preparedStatementMap ) {
-            preparedStatementMap = new ConcurrentHashMap<String, PreparedStatement>();
+            preparedStatementMap = Collections.<String, PreparedStatement>synchronizedMap(
+                    new org.apache.commons.collections.map.LRUMap(MAX_OPEN_PREPARED_STATEMENTS) {
+                @Override
+                protected boolean removeLRU(LinkEntry entry) {
+                    PreparedStatement preparedStatement = (PreparedStatement)entry.getValue();
+                    close(preparedStatement);
+                    return true;
+                }  
+            });
             // As a connection is held by only one thread, we cannot already have a 
             // preparedStatementMap put by another thread
             perConnCache.put(conn, preparedStatementMap);

xdocs/changes.xml

@@ -364,6 +364,7 @@ Previously the default was 1, which could cause unexpected additional traffic.
 <li><bugzilla>54896</bugzilla> - JUnit sampler gives only "failed to create an instance of the class" message with constructor problems.</li>
 <li><bugzilla>55084</bugzilla> - Add timeout support for JDBC Request. Contributed by Mikhail Epikhin (epihin-m at yandex.ru)</li>
 <li><bugzilla>55403</bugzilla> - Enhancement to OS sampler: Support for timeout</li>
+<li><bugzilla>55518</bugzilla> - Add ability to limit number of cached PreparedStatements per connection when "Prepared Select Statement", "Prepared Update Statement" or "Callable Statement" query type is selected</li>
 </ul>
 
 <h3>Controllers</h3>