Fixed Bug:- Multi-Driver Failover when one of multiple hosts down

src/Neo4j/Neo4jConnectionPool.php

@@ -40,14 +40,12 @@
 use Laudis\Neo4j\Databags\SessionConfiguration;
 use Laudis\Neo4j\Enum\AccessMode;
 use Laudis\Neo4j\Enum\RoutingRoles;
+use Laudis\Neo4j\Exception\ConnectionPoolException;
 use Psr\Http\Message\UriInterface;
 use Psr\Log\LogLevel;
 use Psr\SimpleCache\CacheInterface;
 
 use function random_int;
-
-use RuntimeException;
-
 use function sprintf;
 use function str_replace;
 use function time;
@@ -165,7 +163,7 @@ public function acquire(SessionConfiguration $config): Generator
         }
 
         if ($table === null) {
-            throw new RuntimeException(sprintf('Cannot connect to host: "%s". Hosts tried: "%s"', $this->data->getUri()->getHost(), implode('", "', $triedAddresses)), previous: $latestError);
+            throw new ConnectionPoolException(sprintf('Cannot connect to host: "%s". Hosts tried: "%s"', $this->data->getUri()->getHost(), implode('", "', $triedAddresses)), previous: $latestError);
         }
 
         $server = $this->getNextServer($table, $config->getAccessMode());

src/Neo4j/Neo4jDriver.php

@@ -31,6 +31,7 @@
 use Laudis\Neo4j\Databags\ServerInfo;
 use Laudis\Neo4j\Databags\SessionConfiguration;
 use Laudis\Neo4j\Enum\AccessMode;
+use Laudis\Neo4j\Exception\ConnectionPoolException;
 use Laudis\Neo4j\Formatter\SummarizedResultFormatter;
 use Psr\Http\Message\UriInterface;
 use Psr\Log\LogLevel;
@@ -92,7 +93,7 @@ public function verifyConnectivity(?SessionConfiguration $config = null): bool
         $config ??= SessionConfiguration::default();
         try {
             GeneratorHelper::getReturnFromGenerator($this->pool->acquire($config));
-        } catch (ConnectException $e) {
+        } catch (ConnectException|ConnectionPoolException $e) {
             $this->pool->getLogger()?->log(LogLevel::WARNING, 'Could not connect to server on URI '.$this->parsedUrl->__toString(), ['error' => $e]);
 
             return false;

tests/Unit/ClientExceptionHandlingTest.php

@@ -0,0 +1,122 @@
+<?php
+
+declare(strict_types=1);
+
+/*
+ * This file is part of the Neo4j PHP Client and Driver package.
+ *
+ * (c) Nagels <https://nagels.tech>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Laudis\Neo4j\Tests\Unit;
+
+use Laudis\Neo4j\Client;
+use Laudis\Neo4j\Common\DriverSetupManager;
+use Laudis\Neo4j\Databags\SessionConfiguration;
+use Laudis\Neo4j\Databags\TransactionConfiguration;
+use PHPUnit\Framework\TestCase;
+use RuntimeException;
+
+final class ClientExceptionHandlingTest extends TestCase
+{
+    public function testClientRunStatementWithFailingDriver(): void
+    {
+        $driverSetupManager = $this->createMock(DriverSetupManager::class);
+        $sessionConfig = SessionConfiguration::default();
+        $transactionConfig = TransactionConfiguration::default();
+
+        $driverSetupManager->method('getDriver')
+            ->willThrowException(new RuntimeException(
+                'Cannot connect to any server on alias: default with Uris: (\'neo4j://node1:7687\', \'neo4j://node2:7687\')'
+            ));
+
+        $client = new Client($driverSetupManager, $sessionConfig, $transactionConfig);
+
+        $this->expectException(RuntimeException::class);
+        $this->expectExceptionMessage('Cannot connect to any server on alias: default');
+        $client->run('RETURN 1 as n');
+    }
+
+    public function testClientWriteTransactionWithFailingDriver(): void
+    {
+        $driverSetupManager = $this->createMock(DriverSetupManager::class);
+        $sessionConfig = SessionConfiguration::default();
+        $transactionConfig = TransactionConfiguration::default();
+
+        $driverSetupManager->method('getDriver')
+            ->willThrowException(new RuntimeException(
+                'Cannot connect to any server on alias: default with Uris: (\'neo4j://node1:7687\', \'neo4j://node2:7687\')'
+            ));
+
+        $client = new Client($driverSetupManager, $sessionConfig, $transactionConfig);
+
+        $this->expectException(RuntimeException::class);
+        $this->expectExceptionMessage('Cannot connect to any server');
+
+        $client->writeTransaction(function () {
+            return 'test';
+        });
+    }
+
+    public function testClientReadTransactionWithFailingDriver(): void
+    {
+        $driverSetupManager = $this->createMock(DriverSetupManager::class);
+        $sessionConfig = SessionConfiguration::default();
+        $transactionConfig = TransactionConfiguration::default();
+
+        $driverSetupManager->method('getDriver')
+            ->willThrowException(new RuntimeException(
+                'Cannot connect to any server on alias: default with Uris: (\'neo4j://node1:7687\', \'neo4j://node2:7687\')'
+            ));
+
+        $client = new Client($driverSetupManager, $sessionConfig, $transactionConfig);
+
+        $this->expectException(RuntimeException::class);
+        $this->expectExceptionMessage('Cannot connect to any server');
+
+        $client->readTransaction(function () {
+            return 'test';
+        });
+    }
+
+    public function testClientBeginTransactionWithFailingDriver(): void
+    {
+        $driverSetupManager = $this->createMock(DriverSetupManager::class);
+        $sessionConfig = SessionConfiguration::default();
+        $transactionConfig = TransactionConfiguration::default();
+
+        $driverSetupManager->method('getDriver')
+            ->willThrowException(new RuntimeException(
+                'Cannot connect to any server on alias: default with Uris: (\'neo4j://node1:7687\', \'neo4j://node2:7687\')'
+            ));
+
+        $client = new Client($driverSetupManager, $sessionConfig, $transactionConfig);
+
+        $this->expectException(RuntimeException::class);
+        $this->expectExceptionMessage('Cannot connect to any server');
+
+        $client->beginTransaction();
+    }
+
+    public function testClientExceptionIncludesFailedAliasInfo(): void
+    {
+        $driverSetupManager = $this->createMock(DriverSetupManager::class);
+        $sessionConfig = SessionConfiguration::default();
+        $transactionConfig = TransactionConfiguration::default();
+
+        $driverSetupManager->method('getDriver')
+            ->willThrowException(new RuntimeException(
+                'Cannot connect to any server on alias: secondary with Uris: (\'neo4j://node4:7687\', \'neo4j://node5:7687\')'
+            ));
+
+        $client = new Client($driverSetupManager, $sessionConfig, $transactionConfig);
+
+        $this->expectException(RuntimeException::class);
+        $this->expectExceptionMessage('Cannot connect to any server on alias: secondary');
+
+        $client->run('RETURN 1 as n', [], 'secondary');
+    }
+}