THRIFT-2268:Modify TSaslTransport to ignore TCP health checks from loadbalancers

Client: java
Patch: Thiruvel Thirumoolan

Adds a TSaslTransportException to be able to catch and ignore invalid Sasl headers

lib/java/src/org/apache/thrift/server/TThreadPoolServer.java

@@ -28,6 +28,7 @@ import java.util.concurrent.TimeUnit;
 import org.apache.thrift.TException;
 import org.apache.thrift.TProcessor;
 import org.apache.thrift.protocol.TProtocol;
+import org.apache.thrift.transport.TSaslTransportException;
 import org.apache.thrift.transport.TServerTransport;
 import org.apache.thrift.transport.TTransport;
 import org.apache.thrift.transport.TTransportException;
@@ -226,6 +227,8 @@ public class TThreadPoolServer extends TServer {
               break;
             }
         }
+      } catch (TSaslTransportException ttx) {
+        // Something thats not SASL was in the stream, continue silently 
       } catch (TTransportException ttx) {
         // Assume the client died and continue silently
       } catch (TException tx) {

lib/java/src/org/apache/thrift/transport/TSaslTransport.java

@@ -240,6 +240,13 @@ abstract class TSaslTransport extends TTransport {
    */
   @Override
   public void open() throws TTransportException {
+    /*
+     * readSaslHeader is used to tag whether the SASL header has been read properly.
+     * If there is a problem in reading the header, there might not be any
+     * data in the stream, possibly a TCP health check from load balancer.
+     */
+    boolean readSaslHeader = false;
+
     LOGGER.debug("opening transport {}", this);
     if (sasl != null && sasl.isComplete())
       throw new TTransportException("SASL transport already open");
@@ -251,6 +258,7 @@ abstract class TSaslTransport extends TTransport {
       // Negotiate a SASL mechanism. The client also sends its
       // initial response, or an empty one.
       handleSaslStartMessage();
+      readSaslHeader = true;
       LOGGER.debug("{}: Start message handled", getRole());
 
       SaslResponse message = null;
@@ -298,6 +306,17 @@ abstract class TSaslTransport extends TTransport {
       } finally {
         underlyingTransport.close();
       }
+    } catch (TTransportException e) {
+      /*
+       * If there is no-data or no-sasl header in the stream, throw a different
+       * type of exception so we can handle this scenario differently.
+       */
+      if (!readSaslHeader && e.getType() == TTransportException.END_OF_FILE) {
+        underlyingTransport.close();
+        LOGGER.debug("No data or no sasl data in the stream");
+        throw new TSaslTransportException("No data or no sasl data in the stream");
+      }
+      throw e;
     }
 
     String qop = (String) sasl.getNegotiatedProperty(Sasl.QOP);

lib/java/src/org/apache/thrift/transport/TSaslTransportException.java

@@ -0,0 +1,43 @@
+/*
+ * 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.thrift.transport;
+
+/*
+ * This exception is used to track exceptions in TSaslTransport
+ * that does not have Sasl signature in their stream.
+ */
+public class TSaslTransportException extends TTransportException {
+
+  public TSaslTransportException() {
+    super();
+  }
+
+  public TSaslTransportException(String message) {
+    super(message);
+  }
+
+  public TSaslTransportException(Throwable cause) {
+    super(cause);
+  }
+
+  public TSaslTransportException(String message, Throwable cause) {
+    super(message, cause);
+  }
+}