Data Transformation Engine Services Guide

Chapter 19 – Advanced Topics for Mercator Command Server Adapters
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Chapter 19 – Advanced Topics
for Mercator Command
Server Adapters
The following is a summary of the functionality that may be supported by a Mercator
Command Server adapter. This section was written with messaging adapters in mind,
but most of the points are also relevant to other types of adapter.
Summary of Functionality
1. Determine what constitutes a connection and when they can be shared
2. Support adapter scope (map, burst, card)
3. Support completion actions (OnSuccess)
4. Support burst mode – requires remembering the context
5. Have the ability to append multiple messages together. This may require a change to
the type trees in some instances.
6. Support fetch unit to get multiple messages in a single call to ‘Get’
7. Listen option (-LSN) should be cumulative (when applied to multiple messages), but
not cumulative across bursts
8. Provide a quantity (–QTY) option (the total number of messages to be received
across all bursts in a map)
9. Support retries wherever it makes sense (such as connecting to a queue, or sending a
message).
Connection Sharing Wizard
1. Are the connection parameters the same? (for example, queue name, queue manager
name). In the case of the sample user adapter “useradapter”, the relevant parameters
are the service name and the hostname.
2. Is the connection active? If it is then the rules are generally much stricter. If it is
currently not being used in a map then as long as the connection parameters match,
then the connection can be reused.
3. Is the transactional mode the same? If rollback is not specified, there is more
opportunity to share connections.
4. Is the adapter scope the same? If they are not then it still may be possible to share
connections. For example, if we are always deleting on input, always creating on
output and OnFailure is commit in all cases, then it may be possible to handle cards
which have different adapter scopes without problem.
5. Is the card mode the same? If one card is integral, and another is bursting, we may or
may not be able to share the connection.
-QTY, -LSN and FetchUnit
These 3 parameters are related. How they work together is described below.
-QTY