承诺被拒绝的原因：调用等待回调没有解决承诺

Question

我正在尝试通过 Amazon SES 及其 SDK 发送批量电子邮件。我可以看到他们使用GuzzleHttp 来表示承诺。

正在发送电子邮件，一段时间后（有时在 7 封电子邮件之后，有时在 10,000 封之后）我收到来自$promise->wait(); 的异常，并出现以下错误：

PHP 致命错误：未捕获的 GuzzleHttp\Promise\RejectionException：The 承诺被拒绝的原因：调用等待回调没有 在 ... 中解决承诺

相关堆栈跟踪：

#0 /path/to/aws/GuzzleHttp/Promise/Promise.php(75): GuzzleHttp\Promise\exception_for()
#1 /path/to/myfile.php(725): GuzzleHttp\Promise\Promise->wait()

我的代码：

function sendMassEmails($subject, $message, $recipients)
{
    $SesClient = new SesClient([
        'profile' => 'default',
        'version' => '2010-12-01',
        'region' => 'eu-central-1'
    ]);

    $sender_email = 'MyCompany <noreply@mycompany.com>';
    $char_set = 'UTF-8';
    $commands = [];

    foreach ($recipients as $recipient) {
        $commands[] = $SesClient->getCommand('SendEmail', [
            'Destination' => [
                'ToAddresses' => [$recipient],
            ],
            'ReplyToAddresses' => [$sender_email],
            'Source' => $sender_email,
            'Message' => [
                'Body' => [
                    'Html' => [
                        'Charset' => $char_set,
                        'Data' => $message,
                    ],
                    'Text' => [
                        'Charset' => $char_set,
                        'Data' => convert_html_to_text($message),
                    ],
                ],
                'Subject' => [
                    'Charset' => $char_set,
                    'Data' => $subject,
                ],
            ],
            'ConfigurationSetName' => 'MyConfigurationSetName',
        ]);
    }

    $pool = new CommandPool($SesClient, $commands, [
        'concurrency' => 2,
        'before' => function (CommandInterface $cmd, $iteratorId) {
            $a = $cmd->toArray();
            echo sprintf('About to send %d: %s' . PHP_EOL, $iteratorId, $a['Destination']['ToAddresses'][0]);
        },
        'fulfilled' => function (ResultInterface $result, $iteratorId) use ($commands) {
            // log $commands[$iteratorId]['Destination']['ToAddresses'][0]
        },
        'rejected' => function (AwsException $reason, $iteratorId) use ($commands) {
            $logData = sprintf(
                '%s | Reason: %s' . PHP_EOL,
                $commands[$iteratorId]['Destination']['ToAddresses'][0],
                $reason
            );
            // log $logData
        },
    ]);

    $promise = $pool->promise();

    $promise->wait(); // <-- this line throws the exception

    $promise->then(function () {
        // Log 'done'
    });
}

我这样调用函数：

sendMassEmails('Subject', 'Message', ['email1@example.com', 'email2@example.com', ...]);

知道为什么会这样吗？

Answer 1

wait() 方法意味着等待请求完成，即使其中一些请求失败。在代码中，我相信您已经在 CommandPool 中扩展了 EachPromise Class .
因此，您可以尝试将并发数从 2 增加到 4，这意味着现在同时发生 4 个计算，而不是之前的 2，这在我们同时处理大量请求时很好。