user doc: added details about deduplication strategy and delay parameter
@@ -30,9 +30,25 @@ select one of the following:
* `ExchangeIdMessageGroupIdStrategy`
* `PropertyValueMessageGroupIdStrategy`
++
+FIFO queues are designed to ensure that the order in which messages
+are sent and received is strictly preserved and that each message
+is processed exactly once. A FIFO queue name has `.fifo` as a suffix.
+
. In the *Message deduplication ID strategy* field, for a FIFO queue,
accept `NullMessageDeduplicationIdStrategy` or click in the field
to select `ExchangeIdMessageDeduplicationIdStrategy`.
++
+The setting of this parameter has no effect on simple queues. For a FIFO queue,
+the connection uses the selected strategy to ensure that it does not return
+duplicate messages to the integration.
++
+** `NullMessageDeduplicationIdStrategy` uses the message body as the
+deduplication element. In other words, the connection compares message
+bodies to identify duplicate messages.
+** `ExchangeIdMessageDeduplicationIdStrategy` uses the message's exchange
+ID as the deduplication element. In other words, the connection compares
+exchange IDs to identify duplicate messages.
. In the *Queue Name or Amazon Resource Name* field, enter the
name of the queue to send messages to. If the queue does not exist,
@@ -40,7 +56,10 @@ the connection creates it.
. In the *Delay* field, accept the default, which is 0 for no delay.
Or, to add a delay, specify a number. The integration waits this number
-of seconds before sending messages.
+of seconds before sending messages. This is useful when the message
+consumers might not be immediately ready for the messages that the
+connection is sending.
+
. Click *Next*.
