title: Amazon SQS Long Polling not returning all messages
body: <p>I have a requirement to read all messages in my Amazon SQS queue in 1 read and then sort it based on created timestamp and do business logic on it.</p>
  
  <p>To make sure all the SQS hosts are checked for messages, I enabled long polling. The way I did that was to set the default wait time for the queue as 10 seconds. (Any value more than 0 will enable long polling).</p>
  
  <p>However when I tried to read the queue, it still did not give me all the messages and I had to do multiple reads to get all the messages. I even enabled long polling through code per receive request, still did not work. Below is the code I am using.</p>
  
  <pre><code>AmazonSQSClient sqsClient = new AmazonSQSClient(new ClasspathPropertiesFileCredentialsProvider());
  sqsClient.setEndpoint("sqs.us-west-1.amazonaws.com");
  String queueUrl = "https://sqs.us-west-1.amazonaws.com/12345/queueName";
  ReceiveMessageRequest receiveRequest = new ReceiveMessageRequest().withQueueUrl(queueUrl).withMaxNumberOfMessages(10).withWaitTimeSeconds(20);
  List&lt;Message&gt; messages = sqsClient.receiveMessage(receiveRequest).getMessages();
  </code></pre>
  
  <p>I have 3 messages in the queue and each time I run the code I get a different result, sometimes I get all 3 messages, sometimes just 1. The visibility timeout I set as 2 seconds, just to eliminate the messages becoming invisible as the reason for not seeing them in the read.
  This is the expected behavior for short polling. Long polling is supposed to eliminate multiple polls. Is there anything I am doing wrong here? </p>
  
  <p>Thanks    </p>