feat: load balancing of api requests, cleanup api client

.env

@@ -43,7 +43,7 @@ MAILER_DSN=null://null
 APP_BPN_USER=
 APP_BPN_PASSWORD=
 APP_BPN_IP=
-APP_BPN_PORT=
+APP_BPN_PORTS=
 APP_BPN_DEBUG=false
 APP_BPN_CONNECTION_TIMEOUT=5
 APP_BPN_STREAM_TIMEOUT=30

config/services.yaml

@@ -60,7 +60,7 @@ services:
                 bpn_username: '%env(APP_BPN_USER)%'
                 bpn_password: '%env(APP_BPN_PASSWORD)%'
                 bpn_api_ip: '%env(APP_BPN_IP)%'
-                bpn_api_port: '%env(APP_BPN_PORT)%'
+                bpn_api_ports: '%env(csv:APP_BPN_PORTS)%'
                 debug: '%env(bool:APP_BPN_DEBUG)%'
                 connection_timeout: '%env(int:APP_BPN_CONNECTION_TIMEOUT)%'
                 stream_timeout: '%env(int:APP_BPN_STREAM_TIMEOUT)%'

src/BusProNet/ApiClient.php

@@ -6,6 +6,7 @@ use App\BusProNet\DataProcessor\BookingDataProcessor;
 use App\BusProNet\Exception\ApiClientException;
 use App\BusProNet\Exception\ImmediateConnectionCloseException;
 use App\BusProNet\Exception\ResponseParserException;
+use App\BusProNet\Exception\TimeoutException;
 use App\BusProNet\Model\BaseData;
 use App\BusProNet\Model\Booking;
 use App\BusProNet\Model\BookingResponse;
@@ -18,7 +19,6 @@ use App\BusProNet\Model\PurchaseVoucher;
 use App\BusProNet\Model\RegistrationResponse;
 use App\BusProNet\Model\ServiceAvailabilityResponse;
 use App\BusProNet\Model\Travel;
-use App\BusProNet\Traits\ApiClientTrait;
 use App\BusProNet\XmlParser\ApiResponseParser;
 use App\Form\Model\BookingDto;
 use App\Form\Model\RegistrationDto;
@@ -31,8 +31,6 @@ use Symfony\Component\Serializer\SerializerInterface;
 
 class ApiClient
 {
-    use ApiClientTrait;
-
     public const TYPE_NOTIFICATION = 'HINWEIS';
     public const TYPE_CUSTOMER_DATA = 'KUNDENKONTO';
     public const TYPE_BASE_DATA_COUNTRIES = 'STAMMLAENDER';
@@ -48,6 +46,8 @@ class ApiClient
     public const TYPE_PROMO_VOUCHER = 'AKTIONSGUTSCHEIN';
 
     private array $config;
+    private float $operationStartTime;
+    private int $selectedPort;
 
     public function __construct(
         private readonly SerializerInterface $serializer,
@@ -505,32 +505,7 @@ class ApiClient
      */
     public function sendRawXml(string $xml, bool $debug = false): string
     {
-        $maxAttempts = $this->config['busy_retry_attempts'];
+        return $this->executeWithRetry(fn () => $this->doSendRawXml($xml, $debug));
-        $retryDelay = $this->config['busy_retry_delay'];
-        $lastException = null;
-
-        for ($attempt = 1; $attempt <= $maxAttempts; ++$attempt) {
-            try {
-                return $this->doSendRawXml($xml, $debug);
-            } catch (ImmediateConnectionCloseException $e) {
-                $lastException = $e;
-
-                if ($attempt < $maxAttempts) {
-                    $this->logger->warning('BPN server busy, retrying raw XML request', [
-                        'attempt' => $attempt,
-                        'maxAttempts' => $maxAttempts,
-                        'retryDelay' => $retryDelay,
-                    ]);
-                    sleep($retryDelay);
-                }
-            }
-        }
-
-        $this->logger->error('BPN server busy after all retry attempts (raw XML)', [
-            'attempts' => $maxAttempts,
-        ]);
-
-        throw $lastException;
     }
 
     /**
@@ -572,25 +547,19 @@ class ApiClient
 
         $body = $doc->saveXML();
 
-        $this->logger->info('Sending raw XML request to BPN API', [
-            'requestId' => $requestId,
-            'type' => $type,
-        ]);
-
         if (true === $debug || true === $this->config['debug']) {
             $this->dumpXmlToFile('request', $requestId, $body);
         }
 
-        $socket = $this->connect(
+        $socket = $this->connect();
-            $this->config['bpn_api_ip'],
+
-            $this->config['bpn_api_port'],
+        $this->logger->info('Sending raw XML request to BPN API', [
-            $this->config['max_retries'],
+            'requestId' => $requestId,
-            $this->config['connection_timeout'],
+            'type' => $type,
-            $this->config['stream_timeout'],
+            'port' => $this->selectedPort,
-            $this->config['total_timeout']
+        ]);
-        );
+        $this->send($socket, $body);
-        $this->send($socket, $body, $this->config['total_timeout']);
+        $response = $this->receive($socket);
-        $response = $this->receive($socket, $this->config['total_timeout']);
         $this->disconnect($socket);
 
         $responseXml = substr($response, 10);
@@ -603,14 +572,22 @@ class ApiClient
     }
 
     /**
-     * Sends a request to the BPN API with automatic retry on immediate connection close.
+     * @throws ApiClientException
+     */
+    private function sendRequest(string $type, array $data, array $additionalArgs = [], bool $debug = false): mixed
+    {
+        return $this->executeWithRetry(fn () => $this->doSendRequest($type, $data, $additionalArgs, $debug), $type);
+    }
+
+    /**
+     * Executes an operation with automatic retry on immediate connection close.
      *
      * When the BPN server is busy, it may close connections immediately without responding.
      * This method detects such conditions and automatically retries after a short delay.
      *
-     * @throws ApiClientException
+     * @throws ImmediateConnectionCloseException If all retry attempts fail
      */
-    private function sendRequest(string $type, array $data, array $additionalArgs = [], bool $debug = false): mixed
+    private function executeWithRetry(callable $operation, ?string $type = null): mixed
     {
         $maxAttempts = $this->config['busy_retry_attempts'];
         $retryDelay = $this->config['busy_retry_delay'];
@@ -618,26 +595,30 @@ class ApiClient
 
         for ($attempt = 1; $attempt <= $maxAttempts; ++$attempt) {
             try {
-                return $this->doSendRequest($type, $data, $additionalArgs, $debug);
+                return $operation();
             } catch (ImmediateConnectionCloseException $e) {
                 $lastException = $e;
 
                 if ($attempt < $maxAttempts) {
-                    $this->logger->warning('BPN server busy, retrying request', [
+                    $context = [
                         'attempt' => $attempt,
                         'maxAttempts' => $maxAttempts,
                         'retryDelay' => $retryDelay,
-                        'type' => $type,
+                    ];
-                    ]);
+                    if (null !== $type) {
+                        $context['type'] = $type;
+                    }
+                    $this->logger->warning('BPN server busy, retrying request', $context);
                     sleep($retryDelay);
                 }
             }
         }
 
-        $this->logger->error('BPN server busy after all retry attempts', [
+        $context = ['attempts' => $maxAttempts];
-            'attempts' => $maxAttempts,
+        if (null !== $type) {
-            'type' => $type,
+            $context['type'] = $type;
-        ]);
+        }
+        $this->logger->error('BPN server busy after all retry attempts', $context);
 
         throw $lastException;
     }
@@ -660,25 +641,20 @@ class ApiClient
             ])
         ;
 
-        $this->logger->info('Sending request to BPN API', [
-            'requestId' => $requestId,
-            'type' => $data['satz']['@typ'],
-        ]);
-
         if (true === $debug || true === $this->config['debug']) {
             $this->dumpXmlToFile('request', $requestId, $body);
         }
 
-        $socket = $this->connect(
+        $socket = $this->connect();
-            $this->config['bpn_api_ip'],
+
-            $this->config['bpn_api_port'],
+        $this->logger->info('Sending request to BPN API', [
-            $this->config['max_retries'],
+            'requestId' => $requestId,
-            $this->config['connection_timeout'],
+            'type' => $data['satz']['@typ'],
-            $this->config['stream_timeout'],
+            'port' => $this->selectedPort,
-            $this->config['total_timeout']
+        ]);
-        );
+
-        $this->send($socket, $body, $this->config['total_timeout']);
+        $this->send($socket, $body);
-        $response = $this->receive($socket, $this->config['total_timeout']);
+        $response = $this->receive($socket);
         $this->disconnect($socket);
 
         // message length (10 bytes) is prepended to actual message
@@ -716,6 +692,146 @@ class ApiClient
         return md5($username.$password.$date.$type);
     }
 
+    /**
+     * @throws ApiClientException
+     * @throws TimeoutException
+     */
+    private function connect()
+    {
+        // Randomly select a port from the available ports for load balancing
+        $this->selectedPort = $this->config['bpn_api_ports'][array_rand($this->config['bpn_api_ports'])];
+        $this->operationStartTime = microtime(true);
+
+        $tries = 1;
+        $errNo = $errStr = '';
+        $errorCodesForRetry = [
+            SOCKET_ECONNREFUSED,
+            SOCKET_EBADF,
+        ];
+
+        $openSocket = function (&$errNo, &$errStr) {
+            return @fsockopen(
+                $this->config['bpn_api_ip'],
+                $this->selectedPort,
+                $errNo,
+                $errStr,
+                $this->config['connection_timeout']
+            );
+        };
+
+        $socket = $openSocket($errNo, $errStr);
+
+        while (false === $socket && true === in_array($errNo, $errorCodesForRetry) && $this->config['max_retries'] > $tries) {
+            // Check if we've exceeded total timeout during retries
+            if (microtime(true) - $this->operationStartTime > $this->config['total_timeout']) {
+                $this->logger->error('Connection retry timeout exceeded', [
+                    'elapsed_time' => microtime(true) - $this->operationStartTime,
+                    'total_timeout' => $this->config['total_timeout'],
+                ]);
+                throw new TimeoutException('Connection timeout exceeded during retries');
+            }
+
+            $this->logger->warning('Could not connect to socket, retrying', [
+                'error_message' => $errStr,
+                'error_number' => $errNo,
+                'attempt' => $tries,
+            ]);
+            ++$tries;
+            sleep(1);
+            $socket = $openSocket($errNo, $errStr);
+        }
+
+        if (false !== $socket) {
+            stream_set_timeout($socket, $this->config['stream_timeout']);
+        } else {
+            $this->logger->error('Unable to open socket', [
+                'error_message' => $errStr,
+                'error_number' => $errNo,
+                'elapsed_time' => microtime(true) - $this->operationStartTime,
+            ]);
+            throw new ApiClientException('Unable to open socket');
+        }
+
+        return $socket;
+    }
+
+    /**
+     * @throws TimeoutException
+     */
+    private function send($socket, string $data): void
+    {
+        // Check total timeout before sending
+        if (microtime(true) - $this->operationStartTime > $this->config['total_timeout']) {
+            $this->logger->error('Total timeout exceeded before send', [
+                'elapsed_time' => microtime(true) - $this->operationStartTime,
+            ]);
+            throw new TimeoutException('Total operation timeout exceeded before send');
+        }
+
+        // message length is prepended to actual message
+        $send = sprintf('%010s', strlen($data)).$data;
+        fwrite($socket, $send);
+    }
+
+    /**
+     * @throws TimeoutException
+     * @throws ImmediateConnectionCloseException
+     */
+    private function receive($socket): string
+    {
+        $response = '';
+        $readAttempts = 0;
+        $totalTimeout = $this->config['total_timeout'];
+
+        while (false === feof($socket)) {
+            // Check total timeout before each read
+            $elapsedTime = microtime(true) - $this->operationStartTime;
+            if ($elapsedTime > $totalTimeout) {
+                $this->logger->error('Total timeout exceeded during receive', [
+                    'elapsed_time' => $elapsedTime,
+                    'total_timeout' => $totalTimeout,
+                    'bytes_received' => strlen($response),
+                    'read_attempts' => $readAttempts,
+                ]);
+                throw new TimeoutException('Total operation timeout exceeded while receiving data');
+            }
+
+            $chunk = fread($socket, 4096);
+            ++$readAttempts;
+
+            // Check if stream timed out on this specific read
+            $metadata = stream_get_meta_data($socket);
+            if (true === $metadata['timed_out']) {
+                // Check if this is an immediate rejection (0 bytes, < 1 second)
+                // This indicates the server is busy rather than a true timeout
+                if (0 === strlen($response) && $elapsedTime < 1.0) {
+                    $this->logger->warning('Server closed connection immediately', [
+                        'elapsed_time' => $elapsedTime,
+                        'bytes_received' => 0,
+                        'read_attempts' => $readAttempts,
+                    ]);
+                    throw new ImmediateConnectionCloseException('Server closed connection immediately - server may be busy');
+                }
+
+                $this->logger->error('Stream read timeout detected', [
+                    'elapsed_time' => $elapsedTime,
+                    'bytes_received' => strlen($response),
+                    'read_attempts' => $readAttempts,
+                ]);
+                throw new TimeoutException('Stream timeout while reading from socket');
+            }
+
+            $response .= $chunk;
+        }
+
+        return $response;
+    }
+
+    private function disconnect($socket): void
+    {
+        @fclose($socket);
+    }
+
     private function resolveOptions(array $options): array
     {
         $optionsResolver = new OptionsResolver();
@@ -723,8 +839,9 @@ class ApiClient
             'bpn_username',
             'bpn_password',
             'bpn_api_ip',
-            'bpn_api_port',
+            'bpn_api_ports',
         ]);
+        $optionsResolver->setAllowedTypes('bpn_api_ports', ['array']);
         $optionsResolver->setDefaults([
             'max_retries' => 25,
             'debug' => false,

src/BusProNet/Traits/ApiClientTrait.php

@@ -1,149 +0,0 @@
-<?php
-
-namespace App\BusProNet\Traits;
-
-use App\BusProNet\Exception\ApiClientException;
-use App\BusProNet\Exception\ImmediateConnectionCloseException;
-use App\BusProNet\Exception\TimeoutException;
-
-trait ApiClientTrait
-{
-    private float $operationStartTime;
-
-    /**
-     * @throws ApiClientException
-     * @throws TimeoutException
-     */
-    private function connect(string $host, int $port, int $maxRetries = 25, int $connectionTimeout = 5, int $streamTimeout = 30, int $totalTimeout = 45)
-    {
-        $this->operationStartTime = microtime(true);
-
-        $tries = 1;
-        $errNo = $errStr = '';
-        $errorCodesForRetry = [
-            SOCKET_ECONNREFUSED,
-            SOCKET_EBADF,
-        ];
-
-        $openSocket = function (&$errNo, &$errStr) use ($host, $port, $connectionTimeout) {
-            return @fsockopen(
-                $host,
-                $port,
-                $errNo,
-                $errStr,
-                $connectionTimeout
-            );
-        };
-
-        $socket = $openSocket($errNo, $errStr);
-
-        while (false === $socket && true === in_array($errNo, $errorCodesForRetry) && $maxRetries > $tries) {
-            // Check if we've exceeded total timeout during retries
-            if (microtime(true) - $this->operationStartTime > $totalTimeout) {
-                $this->logger->error('Connection retry timeout exceeded', [
-                    'elapsed_time' => microtime(true) - $this->operationStartTime,
-                    'total_timeout' => $totalTimeout,
-                ]);
-                throw new TimeoutException('Connection timeout exceeded during retries');
-            }
-
-            $this->logger->warning('Could not connect to socket, retrying', [
-                'error_message' => $errStr,
-                'error_number' => $errNo,
-                'attempt' => $tries,
-            ]);
-            ++$tries;
-            sleep(1);
-            $socket = $openSocket($errNo, $errStr);
-        }
-
-        if (false !== $socket) {
-            stream_set_timeout($socket, $streamTimeout);
-        } else {
-            $this->logger->error('Unable to open socket', [
-                'error_message' => $errStr,
-                'error_number' => $errNo,
-                'elapsed_time' => microtime(true) - $this->operationStartTime,
-            ]);
-            throw new ApiClientException('Unable to open socket');
-        }
-
-        return $socket;
-    }
-
-    /**
-     * @throws TimeoutException
-     */
-    private function send($socket, string $data, int $totalTimeout): void
-    {
-        // Check total timeout before sending
-        if (microtime(true) - $this->operationStartTime > $totalTimeout) {
-            $this->logger->error('Total timeout exceeded before send', [
-                'elapsed_time' => microtime(true) - $this->operationStartTime,
-            ]);
-            throw new TimeoutException('Total operation timeout exceeded before send');
-        }
-
-        // message length is prepended to actual message
-        $send = sprintf('%010s', strlen($data)).$data;
-        fwrite($socket, $send);
-    }
-
-    /**
-     * @throws TimeoutException
-     * @throws ImmediateConnectionCloseException
-     */
-    private function receive($socket, int $totalTimeout): string
-    {
-        $response = '';
-        $readAttempts = 0;
-
-        while (false === feof($socket)) {
-            // Check total timeout before each read
-            $elapsedTime = microtime(true) - $this->operationStartTime;
-            if ($elapsedTime > $totalTimeout) {
-                $this->logger->error('Total timeout exceeded during receive', [
-                    'elapsed_time' => $elapsedTime,
-                    'total_timeout' => $totalTimeout,
-                    'bytes_received' => strlen($response),
-                    'read_attempts' => $readAttempts,
-                ]);
-                throw new TimeoutException('Total operation timeout exceeded while receiving data');
-            }
-
-            $chunk = fread($socket, 4096);
-            ++$readAttempts;
-
-            // Check if stream timed out on this specific read
-            $metadata = stream_get_meta_data($socket);
-            if (true === $metadata['timed_out']) {
-                // Check if this is an immediate rejection (0 bytes, < 1 second)
-                // This indicates the server is busy rather than a true timeout
-                if (0 === strlen($response) && $elapsedTime < 1.0) {
-                    $this->logger->warning('Server closed connection immediately', [
-                        'elapsed_time' => $elapsedTime,
-                        'bytes_received' => 0,
-                        'read_attempts' => $readAttempts,
-                    ]);
-                    throw new ImmediateConnectionCloseException('Server closed connection immediately - server may be busy');
-                }
-
-                $this->logger->error('Stream read timeout detected', [
-                    'elapsed_time' => $elapsedTime,
-                    'bytes_received' => strlen($response),
-                    'read_attempts' => $readAttempts,
-                ]);
-                throw new TimeoutException('Stream timeout while reading from socket');
-            }
-
-            $response .= $chunk;
-        }
-
-        return $response;
-    }
-
-    private function disconnect($socket): void
-    {
-        @fclose($socket);
-    }
-}