From ec65910627e42f2f4c93ee3c330fe6ce32c9dd03 Mon Sep 17 00:00:00 2001
From: Zhen Li <zhen.li@neotechnology.com>
Date: Fri, 29 Nov 2019 17:56:16 +0100
Subject: [PATCH] Use the supportMultiDb feature detection result, to choose
 the database to connect.

---
 .../internal/async/ImmutableConnectionContext.java     | 10 ++++++----
 .../internal/cluster/loadbalancing/LoadBalancer.java   |  9 +++++----
 2 files changed, 11 insertions(+), 8 deletions(-)

diff --git a/driver/src/main/java/org/neo4j/driver/internal/async/ImmutableConnectionContext.java b/driver/src/main/java/org/neo4j/driver/internal/async/ImmutableConnectionContext.java
index e031fdb3bd..633d9cf20a 100644
--- a/driver/src/main/java/org/neo4j/driver/internal/async/ImmutableConnectionContext.java
+++ b/driver/src/main/java/org/neo4j/driver/internal/async/ImmutableConnectionContext.java
@@ -24,6 +24,7 @@
 import org.neo4j.driver.internal.spi.Connection;
 
 import static org.neo4j.driver.internal.DatabaseNameUtil.defaultDatabase;
+import static org.neo4j.driver.internal.DatabaseNameUtil.systemDatabase;
 import static org.neo4j.driver.internal.InternalBookmark.empty;
 
 /**
@@ -31,7 +32,8 @@
  */
 public class ImmutableConnectionContext implements ConnectionContext
 {
-    private static final ConnectionContext SIMPLE = new ImmutableConnectionContext( defaultDatabase(), empty(), AccessMode.READ );
+    private static final ConnectionContext SINGLE_DB_CONTEXT = new ImmutableConnectionContext( defaultDatabase(), empty(), AccessMode.READ );
+    private static final ConnectionContext MULTI_DB_CONTEXT = new ImmutableConnectionContext( systemDatabase(), empty(), AccessMode.READ );
 
     private final DatabaseName databaseName;
     private final AccessMode mode;
@@ -65,10 +67,10 @@ public Bookmark rediscoveryBookmark()
     /**
      * A simple context is used to test connectivity with a remote server/cluster.
      * As long as there is a read only service, the connection shall be established successfully.
-     * This context should be applicable for both bolt v4 and bolt v3 routing table rediscovery.
+     * Depending on whether multidb is supported or not, this method returns different context for routing table discovery.
      */
-    public static ConnectionContext simple()
+    public static ConnectionContext simple( boolean supportsMultiDb )
     {
-        return SIMPLE;
+        return supportsMultiDb ? MULTI_DB_CONTEXT : SINGLE_DB_CONTEXT;
     }
 }
diff --git a/driver/src/main/java/org/neo4j/driver/internal/cluster/loadbalancing/LoadBalancer.java b/driver/src/main/java/org/neo4j/driver/internal/cluster/loadbalancing/LoadBalancer.java
index c5bf67f885..6a31cf964a 100644
--- a/driver/src/main/java/org/neo4j/driver/internal/cluster/loadbalancing/LoadBalancer.java
+++ b/driver/src/main/java/org/neo4j/driver/internal/cluster/loadbalancing/LoadBalancer.java
@@ -103,19 +103,20 @@ public CompletionStage<Connection> acquireConnection( ConnectionContext context
     @Override
     public CompletionStage<Void> verifyConnectivity()
     {
-        return routingTables.refreshRoutingTable( simple() ).handle( ( ignored, error ) -> {
+        return this.supportsMultiDbAsync().handle( ( supports, error ) -> {
             if ( error != null )
             {
                 Throwable cause = Futures.completionExceptionCause( error );
                 if ( cause instanceof ServiceUnavailableException )
                 {
                     throw Futures.asCompletionException( new ServiceUnavailableException(
-                            "Unable to connect to database, ensure the database is running and that there is a working network connection to it.", cause ) );
+                            "Unable to connect to database management service, ensure the database is running and that there is a working network connection to it.",
+                            cause ) );
                 }
                 throw Futures.asCompletionException( cause );
             }
-            return null;
-        } );
+            return supports;
+        } ).thenCompose( supports -> routingTables.refreshRoutingTable( simple( supports ) ) ).thenApply( ignored -> null );
     }
 
     @Override