adjusted comments and added TODOs for bug 2465

Change-Id: I6c86eee9a4974c4cd22241ab246a3a690075dd78

java/com.sap.sailing.gwt.ui/src/main/java/com/sap/sailing/gwt/ui/adminconsole/ReplicationPanel.java

@@ -268,9 +268,8 @@ public class ReplicationPanel extends FlowPanel {
                 registeredMasters.insertRow(i);
                 registeredMasters.setWidget(i, 0, new Label("Client UUID: " + replicas.getServerIdentifier()));
                 i++;
-                
                 final ReplicationMasterDTO replicatingFromMaster = replicas.getReplicatingFromMaster();
-                if (replicatingFromMaster != null) {
+                if (replicatingFromMaster != null) { // TODO bug 2465: replicating only the user service from a "domain controller master" shouldn't lead to a warning here...
                     errorReporter.reportPersistentInformation(stringMessages.warningServerIsReplica());
                     registeredMasters.insertRow(i);
                     registeredMasters.setWidget(i, 0, new Label(stringMessages.replicatingFromMaster(replicatingFromMaster.getHostname(),

java/com.sap.sailing.gwt.ui/src/main/java/com/sap/sailing/gwt/ui/shared/ReplicationMasterDTO.java

@@ -8,7 +8,13 @@ public class ReplicationMasterDTO implements IsSerializable {
     private int servletPort;
     private String messagingHostname;
     private String exchangeName;
-    ReplicationMasterDTO() {}
+
+    // TODO bug 2465: capture the set of replicables that are replicated from this master; this may be a subset of the
+    // replica's / master's Replicables
+
+    ReplicationMasterDTO() {
+    }
+
     public ReplicationMasterDTO(String hostname, int servletPort, String messagingHostname, int messagingPort, String exchangeName) {
         super();
         this.hostname = hostname;
@@ -17,18 +23,23 @@ public class ReplicationMasterDTO implements IsSerializable {
         this.messagingPort = messagingPort;
         this.exchangeName = exchangeName;
     }
+
     public String getHostname() {
         return hostname;
     }
+
     public int getMessagingPort() {
         return messagingPort;
     }
+
     public int getServletPort() {
         return servletPort;
     }
+
     public String getMessagingHostname() {
         return messagingHostname;
     }
+
     public String getExchangeName() {
         return exchangeName;
     }

java/com.sap.sse.replication/META-INF/MANIFEST.MF

@@ -15,6 +15,7 @@ Require-Bundle: com.sap.sse.common,
  lz4-java;bundle-version="1.3.0",
  org.apache.commons.lang
 Bundle-ClassPath: .
+Comment: The Web-ContextPath is referred to by ReplicationMasterDescriptorImpl.REPLICATION_SERVLET
 Web-ContextPath: /replication
 Import-Package: com.rabbitmq.client;version="2.8.4",
  javax.servlet;version="2.6.0",

java/com.sap.sse.replication/WEB-INF/web.xml

@@ -22,6 +22,7 @@
 	</servlet>
 	<servlet-mapping>
 		<servlet-name>Replication</servlet-name>
+                <!-- See ReplicationMasterDescriptorImpl.REPLICATION_SERVLET referring to this url-pattern -->
 		<url-pattern>/replication</url-pattern>
 	</servlet-mapping>
 </web-app>

java/com.sap.sse.replication/src/com/sap/sse/replication/ReplicationMasterDescriptor.java

@@ -14,6 +14,10 @@ import com.sap.sse.replication.impl.ReplicationServlet;
 /**
  * Identifies a master server instance from which a replica can obtain an initial load and continuous updates.
  * 
+ * TODO bug 2465: add the set of {@link Replicable}s that are replicated from the master represented by this descriptor,
+ * considering that this may be a subset only of the replicables running on this instance or the master server. Example:
+ * replicating only the SecurityService from some other server but being a master regarding all other Replicables.
+ * 
  * @author Frank Mittag, Axel Uhl (d043530)
  *
  */

java/com.sap.sse.replication/src/com/sap/sse/replication/impl/ReplicationMasterDescriptorImpl.java

@@ -44,6 +44,10 @@ public class ReplicationMasterDescriptorImpl implements ReplicationMasterDescrip
 
     private QueueingConsumer consumer;
 
+    // TODO bug 2465: add the set of {@link Replicable}s that are replicated from the master represented by this descriptor,
+    // considering that this may be a subset only of the replicables running on this instance or the master server. Example:
+    //replicating only the SecurityService from some other server but being a master regarding all other Replicables.
+
     /**
      * @param messagingHostname
      *            name of the host on which the exchange is hosted to which this replica connects with a queue whose

java/com.sap.sse.replication/src/com/sap/sse/replication/impl/ReplicationReceiver.java

@@ -66,7 +66,11 @@ public class ReplicationReceiver implements Runnable {
     private static final long CHECK_INTERVAL_MILLIS = 2000; // how long (milliseconds) to pause before checking connection again
     private static final int CHECK_COUNT = 150; // how long to check, value is CHECK_INTERVAL second steps
     
+    /**
+     * descriptor of the master server from which this replicator receives messages
+     */
     private final ReplicationMasterDescriptor master;
+    
     private final ReplicablesProvider replicableProvider;
     
     /**
@@ -138,12 +142,14 @@ public class ReplicationReceiver implements Runnable {
     }
     
     /**
-     * Starts fetching messages from the {@link #consumer}. After receiving a single message, assumes it's an
-     * {@link Iterable} of serialized {@link RacingEventServiceOperation} objects, and applies it to the
-     * {@link RacingEventService} which is obtained from the service tracker passed to this replicator at construction
-     * time.
+     * Starts fetching messages from the {@link #consumer}. After receiving a single message, assumes it's a
+     * {@link ReplicationServiceImpl#createUncompressingInputStream(InputStream) compressed} stream that first
+     * {@link DataInputStream#readUTF() encodes a UTF string} representing the {@link Replicable#getId() replicable ID},
+     * followed by a sequence of serialized {@code byte[]} objects which each can be {@link Replicable#readOperation(InputStream) de-serialized}
+     * by the receiving {@link Replicable} identified by the ID received as a prefix. This method then applies these operations to the
+     * {@link Replicable} identified by the ID, retrieved through the {@link #replicableProvider}.
      * 
-     * @see ReplicationServiceImpl#executed(RacingEventServiceOperation)
+     * @see ReplicationServiceExecutionListener#executed(OperationWithResult)
      */
     @Override
     public void run() {
@@ -170,12 +176,12 @@ public class ReplicationReceiver implements Runnable {
                         }
                     }
                 }
-                byte[] bytesFromMessage = delivery.getBody();
+                final byte[] bytesFromMessage = delivery.getBody();
                 checksPerformed = 0;
                 // Set the replicable's class's class loader as context for deserialization so that all exported classes
                 // of all required bundles/packages can be deserialized at least
                 final InputStream uncompressingInputStream = ReplicationServiceImpl.createUncompressingInputStream(new ByteArrayInputStream(bytesFromMessage));
-                String replicableIdAsString = new DataInputStream(uncompressingInputStream).readUTF();
+                final String replicableIdAsString = new DataInputStream(uncompressingInputStream).readUTF();
                 Replicable<?, ?> replicable = replicableProvider.getReplicable(replicableIdAsString, /* wait */ false);
                 if (replicable != null) {
                     ObjectInputStream ois = new ObjectInputStream(uncompressingInputStream); // no special stream required; only reading a generic byte[]

java/com.sap.sse.replication/src/com/sap/sse/replication/impl/ReplicationServiceImpl.java

@@ -79,7 +79,8 @@ public class ReplicationServiceImpl implements ReplicationService {
 
     /**
      * <code>null</code>, if this instance is not currently replicating from some master; the master's descriptor
-     * otherwise
+     * otherwise; note that partial replication is supported, meaning that only operations for a subset of the
+     * {@link Replicable}s running on this server will be considered when received from the master.
      */
     private ReplicationMasterDescriptor replicatingFromMaster;