Additional logging around refresh of the routing table

driver/src/main/java/org/neo4j/driver/internal/cluster/ClusterComposition.java

@@ -19,12 +19,14 @@
 package org.neo4j.driver.internal.cluster;
 
 import java.util.HashSet;
+import java.util.List;
 import java.util.Set;
 
 import org.neo4j.driver.internal.NetworkSession;
 import org.neo4j.driver.internal.net.BoltServerAddress;
 import org.neo4j.driver.internal.spi.Connection;
 import org.neo4j.driver.internal.util.Clock;
+import org.neo4j.driver.v1.Logger;
 import org.neo4j.driver.v1.Record;
 import org.neo4j.driver.v1.Statement;
 import org.neo4j.driver.v1.StatementResult;
@@ -45,29 +47,29 @@ final class Default implements Provider
         {
             private static final Statement GET_SERVER = new Statement( Provider.GET_SERVERS );
             private final Clock clock;
+            private final Logger log;
 
-            Default( Clock clock )
+            Default( Clock clock, Logger log )
             {
                 this.clock = clock;
+                this.log = log;
             }
 
             @Override
             public ClusterComposition getClusterComposition( Connection connection ) throws ServiceUnavailableException
             {
                 StatementResult cursor = getServers( connection );
+                List<Record> records = cursor.list();
+                log.info( "Got getServers response: %s", records );
                 long now = clock.millis();
                 try
                 {
-                    if ( !cursor.hasNext() )
+                    if ( records.size() != 1 )
                     {
-                        return null; // server returned too few rows, this is a contract violation, treat as incapable
+                        // server returned too few or too many rows, this is a contract violation, treat as incapable
+                        return null;
                     }
-                    Record record = cursor.next();
-                    if ( cursor.hasNext() )
-                    {
-                        return null; // server returned too many rows, this is a contract violation, treat as incapable
-                    }
-                    return read( record, now );
+                    return read( records.get( 0 ), now );
                 }
                 finally
                 {

driver/src/main/java/org/neo4j/driver/internal/cluster/LoadBalancer.java

@@ -51,7 +51,8 @@ public LoadBalancer(
             ConnectionPool connections,
             BoltServerAddress... routingAddresses ) throws ServiceUnavailableException
     {
-        this( settings, clock, log, connections, new ClusterComposition.Provider.Default( clock ), routingAddresses );
+        this( settings, clock, log, connections, new ClusterComposition.Provider.Default( clock, log ),
+                routingAddresses );
     }
 
     LoadBalancer(
@@ -118,6 +119,9 @@ private Connection acquireConnection( RoundRobinAddressSet servers ) throws Serv
                 }
                 catch ( ServiceUnavailableException e )
                 {
+                    log.error( String.format( "Failed to refresh routing information using routing address %s",
+                            address ), e );
+
                     forget( address );
                 }
             }
@@ -129,6 +133,8 @@ private synchronized void ensureRouting() throws ServiceUnavailableException
     {
         if ( stale() )
         {
+            log.info( "Routing information is stale. Ttl %s, currentTime %s, routers %s, writers %s, readers %s",
+                    expirationTimeout, clock.millis(), routers, writers, readers );
             try
             {
                 // get a new routing table
@@ -143,6 +149,9 @@ private synchronized void ensureRouting() throws ServiceUnavailableException
                 {
                     connections.purge( address );
                 }
+
+                log.info( "Refreshed routing information. Ttl %s, routers %s, writers %s, readers %s",
+                        expirationTimeout, routers, writers, readers );
             }
             catch ( InterruptedException e )
             {
@@ -177,6 +186,7 @@ private ClusterComposition lookupRoutingTable() throws InterruptedException, Ser
                 try ( Connection connection = connections.acquire( address ) )
                 {
                     cluster = provider.getClusterComposition( connection );
+                    log.info( "Got cluster composition %s", cluster );
                 }
                 catch ( Exception e )
                 {

driver/src/main/java/org/neo4j/driver/internal/cluster/RoundRobinAddressSet.java

@@ -18,6 +18,7 @@
  */
 package org.neo4j.driver.internal.cluster;
 
+import java.util.Arrays;
 import java.util.Set;
 import java.util.concurrent.atomic.AtomicInteger;
 
@@ -128,6 +129,12 @@ public synchronized void remove( BoltServerAddress address )
         }
     }
 
+    @Override
+    public String toString()
+    {
+        return "RoundRobinAddressSet=" + Arrays.toString( addresses );
+    }
+
     /** breaking encapsulation in order to perform white-box testing of boundary case */
     void setOffset( int target )
     {

driver/src/test/java/org/neo4j/driver/internal/cluster/ClusterCompositionProviderTest.java

@@ -18,22 +18,23 @@
  */
 package org.neo4j.driver.internal.cluster;
 
+import org.junit.Test;
+import org.mockito.invocation.InvocationOnMock;
+import org.mockito.stubbing.Answer;
+import org.mockito.stubbing.Stubber;
+
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.Map;
 import java.util.Set;
 
-import org.junit.Test;
-import org.mockito.invocation.InvocationOnMock;
-import org.mockito.stubbing.Answer;
-import org.mockito.stubbing.Stubber;
-
 import org.neo4j.driver.internal.EventHandler;
 import org.neo4j.driver.internal.net.BoltServerAddress;
 import org.neo4j.driver.internal.spi.Collector;
 import org.neo4j.driver.internal.spi.Connection;
 import org.neo4j.driver.internal.util.FakeClock;
+import org.neo4j.driver.v1.Logger;
 import org.neo4j.driver.v1.Value;
 import org.neo4j.driver.v1.exceptions.ServiceUnavailableException;
 
@@ -148,7 +149,8 @@ public void shouldPropagateConnectionFailureExceptions() throws Exception
 
     private ClusterComposition getClusterComposition()
     {
-        return new ClusterComposition.Provider.Default( clock ).getClusterComposition( connection );
+        return new ClusterComposition.Provider.Default( clock, mock( Logger.class ) )
+                .getClusterComposition( connection );
     }
 
     private void keys( final String... keys )