Define gerrit.replicateOnStartup to control replication

If this variable is set to false, we won't replicate to the remote
peers upon server startup.  This may be useful if a site restarts
their server multiple times per day and has a very big replication
URL set, or has many projects.

Bug: issue 685
Change-Id: I4b4d1b8621e508ad15fd13205a7f34880b839467
Signed-off-by: Shawn O. Pearce <sop@google.com>

Documentation/config-gerrit.txt

@@ -797,6 +797,11 @@ By default unset, as the git daemon must be configured externally
 by the system administrator, and might not even be running on the
 same host as Gerrit.
 
+[[gerrit.replicateOnStartup]]gerrit.replicateOnStartup::
++
+If true, replicates to all remotes on startup to ensure they are
+in-sync with this server.  By default, true.
+
 [[gitweb]]Section gitweb
 ~~~~~~~~~~~~~~~~~~~~~~~~
 

gerrit-server/src/main/java/com/google/gerrit/server/config/MasterNodeStartup.java

@@ -20,6 +20,8 @@ import com.google.gerrit.server.git.PushAllProjectsOp;
 import com.google.gerrit.server.git.ReloadSubmitQueueOp;
 import com.google.inject.Inject;
 
+import org.eclipse.jgit.lib.Config;
+
 import java.util.concurrent.TimeUnit;
 
 /** Configuration for a master node in a cluster of servers. */
@@ -32,17 +34,24 @@ public class MasterNodeStartup extends LifecycleModule {
   static class OnStart implements LifecycleListener {
     private final PushAllProjectsOp.Factory pushAll;
     private final ReloadSubmitQueueOp.Factory submit;
+    private final boolean replicateOnStartup;
 
     @Inject
     OnStart(final PushAllProjectsOp.Factory pushAll,
-        final ReloadSubmitQueueOp.Factory submit) {
+        final ReloadSubmitQueueOp.Factory submit,
+        final @GerritServerConfig Config cfg) {
       this.pushAll = pushAll;
       this.submit = submit;
+
+      replicateOnStartup = cfg.getBoolean("gerrit", "replicateOnStartup", true);
     }
 
     @Override
     public void start() {
-      pushAll.create(null).start(30, TimeUnit.SECONDS);
+      if (replicateOnStartup) {
+        pushAll.create(null).start(30, TimeUnit.SECONDS);
+      }
+
       submit.create().start(15, TimeUnit.SECONDS);
     }