Merge branch '3.1'

Author: dlmarion

server/base/src/main/java/org/apache/accumulo/server/AbstractServer.java

@@ -371,4 +371,11 @@ public void startServiceLockVerificationThread() {
   @Override
   public void close() {}
 
+  protected void waitForUpgrade() throws InterruptedException {
+    while (AccumuloDataVersion.getCurrentVersion(getContext()) < AccumuloDataVersion.get()) {
+      log.info("Waiting for upgrade to complete.");
+      Thread.sleep(1000);
+    }
+  }
+
 }

server/gc/src/main/java/org/apache/accumulo/gc/SimpleGarbageCollector.java

@@ -154,6 +154,14 @@ boolean inSafeMode() {
   @Override
   @SuppressFBWarnings(value = "DM_EXIT", justification = "main class can call System.exit")
   public void run() {
+
+    try {
+      waitForUpgrade();
+    } catch (InterruptedException e) {
+      log.error("Interrupted while waiting for upgrade to complete, exiting...");
+      System.exit(1);
+    }
+
     final VolumeManager fs = getContext().getVolumeManager();
 
     // Sleep for an initial period, giving the manager time to start up and

server/tserver/src/main/java/org/apache/accumulo/tserver/ScanServer.java

@@ -133,6 +133,8 @@
 import com.google.common.collect.Sets;
 import com.google.common.net.HostAndPort;
 
+import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
+
 public class ScanServer extends AbstractServer
     implements TabletScanClientService.Iface, TabletHostingServer {
 
@@ -361,15 +363,24 @@ private ServiceLock announceExistence() {
   }
 
   @Override
+  @SuppressFBWarnings(value = "DM_EXIT", justification = "main class can call System.exit")
   public void run() {
+
+    try {
+      waitForUpgrade();
+    } catch (InterruptedException e) {
+      LOG.error("Interrupted while waiting for upgrade to complete, exiting...");
+      System.exit(1);
+    }
+
     SecurityUtil.serverLogin(getConfiguration());
 
     ServerAddress address = null;
     try {
       address = startScanServerClientService();
       clientAddress = address.getAddress();
     } catch (UnknownHostException e1) {
-      throw new RuntimeException("Failed to start the compactor client service", e1);
+      throw new RuntimeException("Failed to start the scan server client service", e1);
     }
 
     MetricsInfo metricsInfo = getContext().getMetricsInfo();