MWS: Is there a limit on the number of messages in an update request?

Question

I am trying to update product listing on Amazon. I am using Feed API for doing this. What I do is - every half an hour I compile the list orders on our site, and send update requests via API calls. But I stated encountering a problem with this. Some of my requests started getting throttled. On research I found other people questioning request throttling. That explains why I cannot send more than 15 requests in a go as there is a restore period.

So what I plan to do now instead is send multiple update requests in a single feed as:

<?xml version="1.0" encoding="utf-8" ?>
<AmazonEnvelope xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="amzn-
envelope.xsd">
<Header>
<DocumentVersion>1.01</DocumentVersion>
<MerchantIdentifier>M_SELLER_354577</MerchantIdentifier>
</Header>
<MessageType>Inventory</MessageType>
<Message>
<MessageID>1</MessageID>
<OperationType>Update</OperationType>
<Inventory>
<SKU>ASUSVNA1</SKU>
<Quantity>8</Quantity>
<FulfillmentLatency>1</FulfillmentLatency>
</Inventory>
</Message>
<Message>
<MessageID>2</MessageID>
<OperationType>Update</OperationType>
<Inventory>
<SKU>ASUS8VM</SKU>
<Quantity>6</Quantity>
<FulfillmentLatency>1</FulfillmentLatency>
</Inventory>
</Message>
</AmazonEnvelope>

I want to know if there is a limit on the number of messages I can send in a single feed.

Answer 1

There is no limit on the number of messages but the size of the feed is limited to 2,147,483,647 bytes.

For best performance, Amazon recommends keeping the feed size under 10MB and 30,000 messages or fewer: http://docs.developer.amazonservices.com/en_US/feeds/Feeds_SubmitFeed.html