Wait for a raft quorum + logging a message to inform about the wait

Change-Id: I6b1e5a6f2a0ca57e0a435877068ba83bc9311953

@@ -224,16 +224,20 @@ public class DatabaseManager implements DatabaseService, DatabaseAdminService {
         clusterEventListener = new InternalClusterEventListener();
         clusterService.addListener(clusterEventListener);
 
-        if (clusterService.getNodes().size() < clusterConfig.getMembers().size()) {
+        final int raftClusterSize = clusterConfig.getMembers().size();
+        final int raftClusterQuorumSize = (int) (Math.floor(raftClusterSize / 2)) + 1;
+        if (clusterService.getNodes().size() < raftClusterQuorumSize) {
             // current cluster size smaller then expected
             try {
-                if (!clusterEventLatch.await(120, TimeUnit.SECONDS)) {
+                final int waitTimeSec = 120;
+                log.info("Waiting for a maximum of {}s for raft cluster quorum to boot up...", waitTimeSec);
+                if (!clusterEventLatch.await(waitTimeSec, TimeUnit.SECONDS)) {
                     log.info("Starting with {}/{} nodes cluster",
                              clusterService.getNodes().size(),
-                             clusterConfig.getMembers().size());
+                             raftClusterSize);
                 }
             } catch (InterruptedException e) {
-                log.info("Interrupted waiting for others", e);
+                log.info("Interrupted waiting for raft quorum.", e);
             }
         }
     }