Broadcast masterDown() event.

3 files changed, 34 insertions, 5 deletions

diff --git a/same/src/main/java/com/orbekk/same/Client.java b/same/src/main/java/com/orbekk/same/Client.java
index 7079016..fc4a6af 100644
--- a/same/src/main/java/com/orbekk/same/Client.java
+++ b/same/src/main/java/com/orbekk/same/Client.java
@@ -123,6 +123,13 @@ public class Client implements DiscoveryListener {
             Client.this.masterUrl = masterUrl;
             connectionState = ConnectionState.STABLE;
         }
+
+        @Override
+        public void masterDown() throws Exception {
+            logger.info("Master is down.");
+            connectionState = ConnectionState.UNSTABLE;
+            tryBecomeMaster();
+        }
     };
 
     private WorkQueue<String> discoveryThread = new WorkQueue<String>() {
@@ -240,15 +247,30 @@ public class Client implements DiscoveryListener {
         return paxosUrls;
     }
     
-    public void startMasterElection() {
-        if (masterController == null) {
-            logger.warn("Could not become master: No master controller.");
-            return;
-        }
+    private void tryBecomeMaster() {
         List<String> paxosUrls = getPaxosUrls();
         MasterProposer proposer = new MasterProposer(getUrl(), paxosUrls,
                 connections);
         // TODO: Run election.
+        if (masterController == null) {
+            logger.warn("Could not become master: No master controller.");
+            return;
+        }
         masterController.enableMaster(state);
     }
+    
+    public void startMasterElection() {
+        List<String> participants = state.getList(".participants");
+        broadcaster.broadcast(participants, new ServiceOperation() {
+            @Override public void run(String url) {
+                ClientService client = connections.getClient(url);
+                try {
+                    client.masterDown();
+                } catch (Exception e) {
+                    logger.info("{}.masterDown() did not respond (ignored): " +
+                    		url, e);
+                }
+            }
+        });
+    }
 }
diff --git a/same/src/main/java/com/orbekk/same/ClientService.java b/same/src/main/java/com/orbekk/same/ClientService.java
index 453dfef..dfca2cc 100644
--- a/same/src/main/java/com/orbekk/same/ClientService.java
+++ b/same/src/main/java/com/orbekk/same/ClientService.java
@@ -16,4 +16,7 @@ public interface ClientService {
      */
     void masterTakeover(String masterUrl, String networkName,
             int masterId) throws Exception;
+    
+    /** The master is down, so start a new master election. */
+    void masterDown() throws Exception;
 }
diff --git a/same/src/test/java/com/orbekk/same/MasterTest.java b/same/src/test/java/com/orbekk/same/MasterTest.java
index fb5a45c..927b504 100644
--- a/same/src/test/java/com/orbekk/same/MasterTest.java
+++ b/same/src/test/java/com/orbekk/same/MasterTest.java
@@ -38,6 +38,10 @@ public class MasterTest {
         public void masterTakeover(String masterUrl, String networkName, int masterId)
                 throws Exception {
         }
+
+        @Override
+        public void masterDown() throws Exception {
+        }
     }
     
     @Before