title: Amazon MWS - Update product quantity
body: <p>I am using amazon api for update product's quantity using "_POST_INVENTORY_AVAILABILITY_DATA_" feedtype like,</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="utf-8" ?&gt;
  &lt;AmazonEnvelope xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="amzn-envelope.xsd"&gt;
  &lt;Header&gt;
  &lt;DocumentVersion&gt;1.01&lt;/DocumentVersion&gt;
  &lt;MerchantIdentifier&gt;$merchantID&lt;/MerchantIdentifier&gt;
  &lt;/Header&gt;
  &lt;MessageType&gt;Inventory&lt;/MessageType&gt;
  &lt;Message&gt;
  &lt;MessageID&gt;1&lt;/MessageID&gt;
  &lt;OperationType&gt;Update&lt;/OperationType&gt;
  &lt;Inventory&gt;
  &lt;SKU&gt;$SKU&lt;/SKU&gt;
  &lt;Quantity&gt;8&lt;/Quantity&gt;
  &lt;/Inventory&gt;
  &lt;/Message&gt;
  &lt;/AmazonEnvelope&gt;
  
  &lt;?xml version="1.0"?&gt;
  &lt;SubmitFeedResponse xmlns="http://mws.amazonaws.com/doc/2009-01-01/"&gt;
  &lt;SubmitFeedResult&gt;
    &lt;FeedSubmissionInfo&gt;
      &lt;FeedSubmissionId&gt;6791310806&lt;/FeedSubmissionId&gt;
      &lt;FeedType&gt;_POST_INVENTORY_AVAILABILITY_DATA_&lt;/FeedType&gt;
      &lt;SubmittedDate&gt;2013-03-21T19:48:37+00:00&lt;/SubmittedDate&gt;
      &lt;FeedProcessingStatus&gt;_SUBMITTED_&lt;/FeedProcessingStatus&gt;
    &lt;/FeedSubmissionInfo&gt;
  &lt;/SubmitFeedResult&gt;
  &lt;ResponseMetadata&gt;
    &lt;RequestId&gt;fd07bf18-4f6a-4786-bdf9-9d4db50956d0&lt;/RequestId&gt;
  &lt;/ResponseMetadata&gt;
  &lt;/SubmitFeedResponse&gt;
  </code></pre>
  
  <p>but when i try to update 15k or more products at a time by loading products using magento collection quantity not updating in amazon after few hours also. Is it right method or do i need to use any other method?</p>
  
  <p>Can anyone help me?</p>
  
  <p>Thanks in advance.</p>