User defined keys and FRONT ARENA keys

You can create objects in the FRONT ARENA system from a collaboration and update or delete such objects by defining a key for each object type and verb to be supported. This key is needed to correlate replies with the originating requests. The FRONT ARENA application does not provide a consistent internal mechanism for this.

FRONT ARENA keys

For each object created in the FRONT ARENA system, an internal key is generated by the FRONT ARENA application. This key is unique for each object type. For example, all TRADE objects have different internal keys. Internal keys are stored persistently in the primary database table of the object. The column used for storing the key depends on the object type.

Examples for the internal key for TRADE objects are stored in column trdnbr of the TRADE database table. Examples for the internal key for INSTRUMENT objects are stored in the column, insaddr of the INSTRUMENT database table.

AMB message IDs

Each message that is put on the FRONT ARENA AMB bus is assigned a unique message ID by the AMB. This message ID is made available to the AMB client application issuing the message.

If a message is rejected by FRONT ARENA, the error reply returned by the system contains the message ID of the causing message.

This is exploited by the bridge for correlating requests and error replies. The AMB message ID is not externalized by the bridge, however. It is neither part of the reply message sent to the adapter for FRONT ARENA nor part of the business object built by the adapter.

FRONT ARENA keys as user-defined keys

Obviously, the FRONT ARENA key cannot be used in create (insert) scenarios for request-reply correlation. In the cases of updates and deletions it can be used, provided this internal key is known to the requestor.

In scenarios that include all types of requests, the FRONT ARENA keys are not usually utilized. Relationship tables must be maintained and used by the collaborations that are involved for correlating FRONT ARENA objects with the same objects in other systems. Typically, the user-defined key will be used as a key for FRONT ARENA objects in these tables as well.

If different keys are used for different types of requests, several of these tables are required. Thus, the complexity of the collaborations will be increased significantly.

Candidates for user-defined keys

Obviously, only attributes of an object that can be assigned (or internally are assigned) unique values are candidates for user-defined keys. Furthermore, the corresponding database columns must be part of an index.

Candidates can be found in the Keys and Indexes chapter of the FRONT ARENA Data Model Reference (FCA 1051).

Examples:


Table 26. Stanza RequestHandler/ObjectKeys:

Keyword Mandatory/ Optional/ Default value Possible values Description

<requesttype>_<ob ject>

Mandatory The name of the attribute of <object>. The name of the attribute of <object> to be used as the user key if a request of type <request type> is performed for <object>.

Valid <request type>'s: INSERT, UPDATE, and DELETE.

Valid <object>'s: TRADE, INSTRUMENT, etc. (any FRONT ARENA objects)

Example:

[RequestHandler/ObjectKeys]
INSERT_TRADE = OPTIONAL_KEY
UPDATE_TRADE = TRDNBR
DELETE_TRADE = TRDNBR

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