Remove stacktrace from recoverable discovery log warnings (#943) (#954)

* Remove stacktrace from recoverable discovery log warnings

This is to reduce the noise in the logs when recoverable discovery exceptions occur. Complete discovery failures are expected to be reported separately.

* Update class comment on RediscoveryImpl

Author: injectives

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

@@ -25,8 +25,21 @@
 import org.neo4j.driver.internal.BoltServerAddress;
 import org.neo4j.driver.internal.spi.ConnectionPool;
 
+/**
+ * Provides cluster composition lookup capabilities and initial router address resolution.
+ */
 public interface Rediscovery
 {
+    /**
+     * Fetches cluster composition using the provided routing table.
+     * <p>
+     * Implementation must be thread safe to be called with distinct routing tables concurrently. The routing table instance may be modified.
+     *
+     * @param routingTable   the routing table for cluster composition lookup
+     * @param connectionPool the connection pool for connection acquisition
+     * @param bookmark       the bookmark that is presented to the server
+     * @return cluster composition lookup result
+     */
     CompletionStage<ClusterComposition> lookupClusterComposition( RoutingTable routingTable, ConnectionPool connectionPool, Bookmark bookmark );
 
     List<BoltServerAddress> resolve();

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

@@ -49,14 +49,13 @@
 import static org.neo4j.driver.internal.util.Futures.completedWithNull;
 import static org.neo4j.driver.internal.util.Futures.failedFuture;
 
-/**
- * This class is used by all router tables to perform discovery.
- * In other words, the methods in this class could be called by multiple threads concurrently.
- */
 public class RediscoveryImpl implements Rediscovery
 {
     private static final String NO_ROUTERS_AVAILABLE = "Could not perform discovery for database '%s'. No routing server available.";
     private static final String RECOVERABLE_ROUTING_ERROR = "Failed to update routing table with server '%s'.";
+    private static final String RECOVERABLE_DISCOVERY_ERROR_WITH_SERVER = "Received a recoverable discovery error with server '%s', " +
+                                                                          "will continue discovery with other routing servers if available. " +
+                                                                          "Complete routing failures will be reported separately from this warning.";
 
     private final BoltServerAddress initialRouter;
     private final RoutingSettings settings;
@@ -258,8 +257,9 @@ private ClusterComposition handleRoutingProcedureError( Throwable error, Routing
         // Retriable error happened during discovery.
         DiscoveryException discoveryError = new DiscoveryException( format( RECOVERABLE_ROUTING_ERROR, routerAddress ), error );
         Futures.combineErrors( baseError, discoveryError ); // we record each failure here
-        logger.warn( format( "Received a recoverable discovery error with server '%s', will continue discovery with other routing servers if available.",
-                routerAddress ), discoveryError );
+        String warningMessage = format( RECOVERABLE_DISCOVERY_ERROR_WITH_SERVER, routerAddress );
+        logger.warn( warningMessage );
+        logger.debug( warningMessage, discoveryError );
         routingTable.forget( routerAddress );
         return null;
     }

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

@@ -52,7 +52,6 @@
 import static org.junit.jupiter.api.Assertions.assertNotNull;
 import static org.junit.jupiter.api.Assertions.assertThrows;
 import static org.mockito.ArgumentMatchers.any;
-import static org.mockito.ArgumentMatchers.anyString;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.never;
 import static org.mockito.Mockito.startsWith;
@@ -182,9 +181,14 @@ void shouldFailImmediatelyWhenClusterCompositionProviderReturnsFailure()
         ClusterComposition composition = await( rediscovery.lookupClusterComposition( table, pool, empty() ) );
         assertEquals( validComposition, composition );
 
-        ArgumentCaptor<DiscoveryException> argument = ArgumentCaptor.forClass( DiscoveryException.class );
-        verify( logger ).warn( anyString(), argument.capture() );
-        assertThat( argument.getValue().getCause(), equalTo( protocolError ) );
+        ArgumentCaptor<String> warningMessageCaptor = ArgumentCaptor.forClass( String.class );
+        ArgumentCaptor<String> debugMessageCaptor = ArgumentCaptor.forClass( String.class );
+        ArgumentCaptor<DiscoveryException> debugThrowableCaptor = ArgumentCaptor.forClass( DiscoveryException.class );
+        verify( logger ).warn( warningMessageCaptor.capture() );
+        verify( logger ).debug( debugMessageCaptor.capture(), debugThrowableCaptor.capture() );
+        assertNotNull( warningMessageCaptor.getValue() );
+        assertEquals( warningMessageCaptor.getValue(), debugMessageCaptor.getValue() );
+        assertThat( debugThrowableCaptor.getValue().getCause(), equalTo( protocolError ) );
     }
 
     @Test