Decoupling JDBCBackendConnection from ConnectionSession (apache#13975)

shardingsphere-agent/shardingsphere-agent-plugins/shardingsphere-agent-plugin-tracing/shardingsphere-agent-tracing-jaeger/src/main/java/org/apache/shardingsphere/agent/plugin/tracing/jaeger/advice/CommandExecutorTaskAdvice.java

@@ -27,7 +27,8 @@
 import org.apache.shardingsphere.agent.plugin.tracing.jaeger.constant.JaegerConstants;
 import org.apache.shardingsphere.agent.plugin.tracing.jaeger.span.JaegerErrorSpan;
 import org.apache.shardingsphere.infra.executor.kernel.model.ExecutorDataMap;
-import org.apache.shardingsphere.proxy.backend.communication.jdbc.connection.JDBCConnectionSession;
+import org.apache.shardingsphere.proxy.backend.communication.jdbc.connection.JDBCBackendConnection;
+import org.apache.shardingsphere.proxy.backend.session.ConnectionSession;
 import org.apache.shardingsphere.proxy.frontend.command.CommandExecutorTask;
 
 import java.lang.reflect.Field;
@@ -54,7 +55,7 @@ public void afterMethod(final AdviceTargetObject target, final Method method, fi
         ExecutorDataMap.getValue().remove(JaegerConstants.ROOT_SPAN);
         Field field = CommandExecutorTask.class.getDeclaredField("connectionSession");
         field.setAccessible(true);
-        JDBCConnectionSession connection = (JDBCConnectionSession) field.get(target);
+        JDBCBackendConnection connection = (JDBCBackendConnection) ((ConnectionSession) field.get(target)).getBackendConnection();
         Scope scope = GlobalTracer.get().scopeManager().active();
         scope.span().setTag(JaegerConstants.ShardingSphereTags.CONNECTION_COUNT.getKey(), connection.getConnectionSize());
         scope.close();

shardingsphere-agent/shardingsphere-agent-plugins/shardingsphere-agent-plugin-tracing/shardingsphere-agent-tracing-opentracing/src/test/java/org/apache/shardingsphere/agent/plugin/tracing/opentracing/advice/CommandExecutorTaskAdviceTest.java

@@ -25,7 +25,6 @@
 import lombok.SneakyThrows;
 import org.apache.shardingsphere.agent.api.result.MethodInvocationResult;
 import org.apache.shardingsphere.db.protocol.payload.PacketPayload;
-import org.apache.shardingsphere.proxy.backend.communication.jdbc.connection.JDBCConnectionSession;
 import org.apache.shardingsphere.proxy.frontend.command.CommandExecutorTask;
 import org.junit.Before;
 import org.junit.BeforeClass;
@@ -58,7 +57,7 @@ public static void setup() {
         }
         FieldReader fieldReader = new FieldReader(GlobalTracer.get(), GlobalTracer.class.getDeclaredField("tracer"));
         tracer = (MockTracer) fieldReader.read();
-        executeCommandMethod = CommandExecutorTask.class.getDeclaredMethod("executeCommand", ChannelHandlerContext.class, PacketPayload.class, JDBCConnectionSession.class);
+        executeCommandMethod = CommandExecutorTask.class.getDeclaredMethod("executeCommand", ChannelHandlerContext.class, PacketPayload.class);
     }
 
     @Before

shardingsphere-agent/shardingsphere-agent-plugins/shardingsphere-agent-plugin-tracing/shardingsphere-agent-tracing-test/src/main/java/org/apache/shardingsphere/agent/plugin/tracing/advice/AbstractCommandExecutorTaskAdviceTest.java

@@ -21,7 +21,8 @@
 import lombok.Getter;
 import org.apache.shardingsphere.agent.api.advice.AdviceTargetObject;
 import org.apache.shardingsphere.agent.plugin.tracing.AgentRunner;
-import org.apache.shardingsphere.proxy.backend.communication.jdbc.connection.JDBCConnectionSession;
+import org.apache.shardingsphere.proxy.backend.communication.jdbc.connection.JDBCBackendConnection;
+import org.apache.shardingsphere.proxy.backend.session.ConnectionSession;
 import org.apache.shardingsphere.proxy.frontend.command.CommandExecutorTask;
 import org.apache.shardingsphere.transaction.core.TransactionType;
 import org.junit.runner.RunWith;
@@ -35,7 +36,10 @@ public abstract class AbstractCommandExecutorTaskAdviceTest implements AdviceTes
     @SuppressWarnings("ConstantConditions")
     @Override
     public final void prepare() {
-        Object executorTask = new CommandExecutorTask(null, new JDBCConnectionSession(TransactionType.BASE, new DefaultAttributeMap()), null, null);
+        ConnectionSession connectionSession = new ConnectionSession(TransactionType.BASE, new DefaultAttributeMap());
+        JDBCBackendConnection backendConnection = new JDBCBackendConnection(connectionSession);
+        connectionSession.setBackendConnection(backendConnection);
+        Object executorTask = new CommandExecutorTask(null, connectionSession, null, null);
         targetObject = (AdviceTargetObject) executorTask;
     }
 }

shardingsphere-agent/shardingsphere-agent-plugins/shardingsphere-agent-plugin-tracing/shardingsphere-agent-tracing-zipkin/src/main/java/org/apache/shardingsphere/agent/plugin/tracing/zipkin/advice/CommandExecutorTaskAdvice.java

@@ -25,7 +25,8 @@
 import org.apache.shardingsphere.agent.api.result.MethodInvocationResult;
 import org.apache.shardingsphere.agent.plugin.tracing.zipkin.constant.ZipkinConstants;
 import org.apache.shardingsphere.infra.executor.kernel.model.ExecutorDataMap;
-import org.apache.shardingsphere.proxy.backend.communication.jdbc.connection.JDBCConnectionSession;
+import org.apache.shardingsphere.proxy.backend.communication.jdbc.connection.JDBCBackendConnection;
+import org.apache.shardingsphere.proxy.backend.session.ConnectionSession;
 import org.apache.shardingsphere.proxy.frontend.command.CommandExecutorTask;
 
 import java.lang.reflect.Field;
@@ -51,7 +52,7 @@ public void beforeMethod(final AdviceTargetObject target, final Method method, f
     public void afterMethod(final AdviceTargetObject target, final Method method, final Object[] args, final MethodInvocationResult result) {
         Field field = CommandExecutorTask.class.getDeclaredField("connectionSession");
         field.setAccessible(true);
-        JDBCConnectionSession connection = (JDBCConnectionSession) field.get(target);
+        JDBCBackendConnection connection = (JDBCBackendConnection) ((ConnectionSession) field.get(target)).getBackendConnection();
         Span span = (Span) ExecutorDataMap.getValue().remove(ZipkinConstants.ROOT_SPAN);
         span.tag(ZipkinConstants.Tags.CONNECTION_COUNT, String.valueOf(connection.getConnectionSize()));
         span.finish();

shardingsphere-proxy/shardingsphere-proxy-backend/src/main/java/org/apache/shardingsphere/proxy/backend/communication/BackendConnection.java

@@ -0,0 +1,55 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.shardingsphere.proxy.backend.communication;
+
+import org.apache.shardingsphere.proxy.backend.exception.BackendConnectionException;
+import org.apache.shardingsphere.proxy.backend.session.ConnectionSession;
+
+/**
+ * Backend connection for Proxy.
+ */
+public interface BackendConnection {
+
+    /**
+     * Get connection session of backend connection.
+     * 
+     * @return connection session
+     */
+    ConnectionSession getConnectionSession();
+
+    /**
+     * Prepare for task execution.
+     *
+     * @throws BackendConnectionException backend connection exception
+     */
+    void prepareForTaskExecution() throws BackendConnectionException;
+
+    /**
+     * Close resources used in execution.
+     *
+     * @throws BackendConnectionException backend connection exception
+     */
+    void closeExecutionResources() throws BackendConnectionException;
+
+    /**
+     * Close all resources.
+     * 
+     * @throws BackendConnectionException backend connection exception
+     */
+    void closeAllResources() throws BackendConnectionException;
+}

shardingsphere-proxy/shardingsphere-proxy-backend/src/main/java/org/apache/shardingsphere/proxy/backend/communication/DatabaseCommunicationEngine.java

@@ -33,7 +33,7 @@
 import org.apache.shardingsphere.infra.merge.result.MergedResult;
 import org.apache.shardingsphere.infra.metadata.ShardingSphereMetaData;
 import org.apache.shardingsphere.infra.rule.identifier.type.DataNodeContainedRule;
-import org.apache.shardingsphere.proxy.backend.communication.jdbc.connection.JDBCConnectionSession;
+import org.apache.shardingsphere.proxy.backend.communication.jdbc.connection.JDBCBackendConnection;
 import org.apache.shardingsphere.proxy.backend.context.ProxyContext;
 import org.apache.shardingsphere.proxy.backend.response.data.QueryResponseCell;
 import org.apache.shardingsphere.proxy.backend.response.data.QueryResponseRow;
@@ -83,14 +83,14 @@ public final class DatabaseCommunicationEngine {
 
     private final Collection<ResultSet> cachedResultSets = new CopyOnWriteArrayList<>();
 
-    public DatabaseCommunicationEngine(final String driverType, final ShardingSphereMetaData metaData, final LogicSQL logicSQL, final JDBCConnectionSession connectionSession) {
+    public DatabaseCommunicationEngine(final String driverType, final ShardingSphereMetaData metaData, final LogicSQL logicSQL, final JDBCBackendConnection backendConnection) {
         this.driverType = driverType;
         this.metaData = metaData;
         this.logicSQL = logicSQL;
-        proxySQLExecutor = new ProxySQLExecutor(driverType, connectionSession, this);
+        proxySQLExecutor = new ProxySQLExecutor(driverType, backendConnection, this);
         kernelProcessor = new KernelProcessor();
         metadataRefreshEngine = new MetaDataRefreshEngine(metaData,
-                ProxyContext.getInstance().getContextManager().getMetaDataContexts().getOptimizerContext().getMetaData().getSchemas().get(connectionSession.getSchemaName()),
+                ProxyContext.getInstance().getContextManager().getMetaDataContexts().getOptimizerContext().getMetaData().getSchemas().get(backendConnection.getConnectionSession().getSchemaName()),
                 ProxyContext.getInstance().getContextManager().getMetaDataContexts().getProps());
     }
 

shardingsphere-proxy/shardingsphere-proxy-backend/src/main/java/org/apache/shardingsphere/proxy/backend/communication/DatabaseCommunicationEngineFactory.java

@@ -23,7 +23,7 @@
 import org.apache.shardingsphere.infra.binder.statement.SQLStatementContext;
 import org.apache.shardingsphere.infra.executor.sql.prepare.driver.jdbc.JDBCDriverType;
 import org.apache.shardingsphere.infra.metadata.ShardingSphereMetaData;
-import org.apache.shardingsphere.proxy.backend.communication.jdbc.connection.JDBCConnectionSession;
+import org.apache.shardingsphere.proxy.backend.communication.jdbc.connection.JDBCBackendConnection;
 import org.apache.shardingsphere.proxy.backend.context.ProxyContext;
 
 import java.util.Collections;
@@ -51,14 +51,14 @@ public static DatabaseCommunicationEngineFactory getInstance() {
      *
      * @param sqlStatementContext SQL statement context
      * @param sql SQL to be executed
-     * @param connectionSession connection session
+     * @param backendConnection backend connection
      * @return text protocol backend handler
      */
-    public DatabaseCommunicationEngine newTextProtocolInstance(final SQLStatementContext<?> sqlStatementContext, final String sql, final JDBCConnectionSession connectionSession) {
-        ShardingSphereMetaData metaData = ProxyContext.getInstance().getMetaData(connectionSession.getSchemaName());
+    public DatabaseCommunicationEngine newTextProtocolInstance(final SQLStatementContext<?> sqlStatementContext, final String sql, final JDBCBackendConnection backendConnection) {
+        ShardingSphereMetaData metaData = ProxyContext.getInstance().getMetaData(backendConnection.getConnectionSession().getSchemaName());
         LogicSQL logicSQL = new LogicSQL(sqlStatementContext, sql, Collections.emptyList());
-        DatabaseCommunicationEngine result = new DatabaseCommunicationEngine(JDBCDriverType.STATEMENT, metaData, logicSQL, connectionSession);
-        connectionSession.add(result);
+        DatabaseCommunicationEngine result = new DatabaseCommunicationEngine(JDBCDriverType.STATEMENT, metaData, logicSQL, backendConnection);
+        backendConnection.add(result);
         return result;
     }
 
@@ -68,15 +68,15 @@ public DatabaseCommunicationEngine newTextProtocolInstance(final SQLStatementCon
      * @param sqlStatementContext SQL statement context
      * @param sql SQL to be executed
      * @param parameters SQL parameters
-     * @param connectionSession connection session
+     * @param backendConnection backend connection
      * @return binary protocol backend handler
      */
     public DatabaseCommunicationEngine newBinaryProtocolInstance(final SQLStatementContext<?> sqlStatementContext, final String sql, 
-                                                                 final List<Object> parameters, final JDBCConnectionSession connectionSession) {
-        ShardingSphereMetaData metaData = ProxyContext.getInstance().getMetaData(connectionSession.getSchemaName());
+                                                                 final List<Object> parameters, final JDBCBackendConnection backendConnection) {
+        ShardingSphereMetaData metaData = ProxyContext.getInstance().getMetaData(backendConnection.getConnectionSession().getSchemaName());
         LogicSQL logicSQL = new LogicSQL(sqlStatementContext, sql, parameters);
-        DatabaseCommunicationEngine result = new DatabaseCommunicationEngine(JDBCDriverType.PREPARED_STATEMENT, metaData, logicSQL, connectionSession);
-        connectionSession.add(result);
+        DatabaseCommunicationEngine result = new DatabaseCommunicationEngine(JDBCDriverType.PREPARED_STATEMENT, metaData, logicSQL, backendConnection);
+        backendConnection.add(result);
         return result;
     }
 }