Remove unused methods from Neo4jRunner

Add guard against running when another Neo4j instance is running.

The Neo4jRunner contained a lot of functionality that was not
used, with four separate code paths for starting Neo4j, which made
it somewhat complex to reason about how to prevent starting Neo4j
over an existing instance. This removes those unused code paths and
consolidates API usage to one main start path.

Author: jakewins

driver/src/main/java/org/neo4j/driver/internal/pool/InternalConnectionPool.java

@@ -65,16 +65,22 @@ public class InternalConnectionPool implements ConnectionPool
      */
     private final ValidationStrategy<PooledConnection> connectionValidation;
 
+    /**
+     * Timeout in milliseconds if there are no available sessions.
+     */
+    private final long acquireSessionTimeout;
+
     private final Clock clock;
     private final Config config;
 
     public InternalConnectionPool( Config config )
     {
-        this( loadConnectors(), Clock.SYSTEM, config );
+        this( loadConnectors(), Clock.SYSTEM, config, Long.getLong( "neo4j.driver.acquireSessionTimeout", 30_000 ) );
     }
 
-    public InternalConnectionPool( Collection<Connector> conns, Clock clock, Config config )
+    public InternalConnectionPool( Collection<Connector> conns, Clock clock, Config config, long acquireTimeout )
     {
+        this.acquireSessionTimeout = acquireTimeout;
         this.config = config;
         this.clock = clock;
         this.connectionValidation = new PooledConnectionValidator( config.idleTimeBeforeConnectionTest() );
@@ -92,7 +98,7 @@ public Connection acquire( URI sessionURI )
     {
         try
         {
-            Connection conn = pool( sessionURI ).acquire( 30, TimeUnit.SECONDS );
+            Connection conn = pool( sessionURI ).acquire( acquireSessionTimeout, TimeUnit.MILLISECONDS );
             if( conn == null )
             {
                 throw new ClientException(

driver/src/test/java/org/neo4j/driver/internal/pool/InternalConnectionPoolTest.java

@@ -53,7 +53,7 @@ public void shouldThrowExceptionWhenConnectionPoolIsFull() throws Throwable
         Connector connector = connector( "bolt" );
         Config config = Config.build().withConnectionPoolSize( 1 ).toConfig();
         InternalConnectionPool pool = new InternalConnectionPool( singletonList( connector ),
-                Clock.SYSTEM, config );
+                Clock.SYSTEM, config, 100 );
 
         // When & Then
         pool.acquire( uri );
@@ -74,7 +74,7 @@ public void shouldAcquireAndRelease() throws Throwable
         Connector connector = connector( "bolt" );
         Config config = Config.defaultConfig();
         InternalConnectionPool pool = new InternalConnectionPool( singletonList( connector ),
-                Clock.SYSTEM, config );
+                Clock.SYSTEM, config, 100 );
 
         Connection conn = pool.acquire( uri );
         conn.close();

driver/src/test/java/org/neo4j/driver/v1/integration/ConnectionPoolIT.java

@@ -18,14 +18,14 @@
  */
 package org.neo4j.driver.v1.integration;
 
-import java.util.LinkedList;
-import java.util.concurrent.CountDownLatch;
-import java.util.concurrent.TimeUnit;
-
 import org.junit.After;
 import org.junit.Rule;
 import org.junit.Test;
 
+import java.util.LinkedList;
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.TimeUnit;
+
 import org.neo4j.driver.v1.Driver;
 import org.neo4j.driver.v1.GraphDatabase;
 import org.neo4j.driver.v1.Session;
@@ -53,7 +53,7 @@ public void shouldRecoverFromDownedServer() throws Throwable
         sessionGrabber.start();
 
         // When
-        neo4j.restartServerOnEmptyDatabase();
+        neo4j.restart();
 
         // Then we accept a hump with failing sessions, but demand that failures stop as soon as the server is back up.
         sessionGrabber.assertSessionsAvailableWithin( 60 );

driver/src/test/java/org/neo4j/driver/v1/integration/SSLSocketChannelIT.java

@@ -44,7 +44,6 @@
 import org.neo4j.driver.v1.ResultCursor;
 import org.neo4j.driver.v1.util.CertificateToolTest;
 import org.neo4j.driver.v1.util.Neo4jRunner;
-import org.neo4j.driver.v1.util.Neo4jSettings;
 import org.neo4j.driver.v1.util.TestNeo4j;
 
 import static org.junit.Assert.assertEquals;
@@ -59,7 +58,7 @@
 public class SSLSocketChannelIT
 {
     @Rule
-    public TestNeo4j neo4j = new TestNeo4j( Neo4jSettings.DEFAULT.usingTLS( true ) );
+    public TestNeo4j neo4j = new TestNeo4j();
 
     @Test
     public void shouldPerformTLSHandshakeWithEmptyKnownCertsFile() throws Throwable

driver/src/test/java/org/neo4j/driver/v1/integration/ServerKilledIT.java

@@ -21,15 +21,14 @@
 import org.junit.Rule;
 import org.junit.Test;
 
-import org.neo4j.driver.v1.GraphDatabase;
 import org.neo4j.driver.v1.Driver;
+import org.neo4j.driver.v1.GraphDatabase;
 import org.neo4j.driver.v1.Session;
 import org.neo4j.driver.v1.exceptions.ClientException;
 import org.neo4j.driver.v1.util.Neo4jRunner;
 import org.neo4j.driver.v1.util.TestNeo4j;
 
 import static org.junit.Assert.fail;
-import static org.junit.Assume.assumeTrue;
 
 /**
  * Mainly concerned about the connection pool - we want to make sure that bad connections are evacuated from the
@@ -44,9 +43,6 @@ public class ServerKilledIT
     public void shouldRecoverFromServerRestart() throws Throwable
     {
         // Given
-        assumeTrue( neo4j.canControlServer() );
-
-        // And given we've spun up a few running sessions
         try ( Driver driver = GraphDatabase.driver( Neo4jRunner.DEFAULT_URL ) )
         {
             Session s1 = driver.session();
@@ -61,7 +57,7 @@ public void shouldRecoverFromServerRestart() throws Throwable
             s4.close();
 
             // When
-            neo4j.restartServerOnEmptyDatabase();
+            neo4j.restart();
 
             // Then we should be able to start using sessions again, at most O(numSessions) session calls later
             // TODO: These should value evicted immediately, not show up as application-loggingLevel errors first

driver/src/test/java/org/neo4j/driver/v1/stress/DriverStresser.java

@@ -33,6 +33,7 @@
 import org.neo4j.driver.v1.Session;
 import org.neo4j.driver.v1.Value;
 import org.neo4j.driver.v1.util.Neo4jRunner;
+import org.neo4j.driver.v1.util.Neo4jSettings;
 
 import static org.neo4j.driver.v1.Values.parameters;
 
@@ -57,7 +58,7 @@ public static void main( String... args ) throws Throwable
     public static void setup() throws Exception
     {
         server = Neo4jRunner.getOrCreateGlobalRunner();
-        server.startServerOnEmptyDatabase();
+        server.ensureRunning( Neo4jSettings.DEFAULT );
         driver = GraphDatabase.driver( "bolt://localhost" );
     }
 
@@ -88,7 +89,7 @@ public int operation()
     public static void tearDown() throws Exception
     {
         driver.close();
-        server.stopServerIfRunning();
+        server.stop();
     }