Cost-Based Optimization of Integration Flows - Datenbanken ...

2.4 Use Cases
message) is used. The Join operator (o 4 ) merges the result message with the received
message (with the customer key as join predicate). Finally, an Assign operator (o 5 ) and
an Invoke operator (o 6 ) are used to sent the join result to system s 3 (ERP system).
Example 2.6 (Material Inventory Update). The ERP system is the leading information
system in our example scenario. Hence, the current material inventory is periodically
updated within the ERP system. Therefore, the integration flow (plan P 3 ) that is shown
in Figure 2.9(c) is periodically executed. Essentially, this plan specifies that after a query
has been prepared, the external systems s 1 (SCM system) and s 2 (Material system) are
queried. The result sets are joined (o 4 ) and aggregated (o 5 ) per material. Finally, the
aggregated material inventory is sent to the ERP system s 3 .
Example 2.7 (Product Cost Estimate). Using the eCommerce Web shop, a customer
can order user-defined products. Therefore, one can pose a cost estimate bid. In order
to answer such a cost estimate bid, data from several operational systems is required.
Therefore, the synchronous integration flow (plan P 4 ) shown in Figure 2.10 is used.
Receive (o1)
[service: s5, out: msg1]
Assign (o2)
[in: msg1, out: msg2]
Invoke (o3)
[service s3, in: msg2, out: msg3]
Translation (o4)
[in: msg3, out: msg4]
Join (o5)
[in: msg1,msg4, out: msg5]
LEFT OUTER
A1_Productkey>0
Switch (o6)
[in: msg5]
Assign (o7)
[in: msg5, out: msg6]
Invoke (o8)
[service s1, in: msg6, out: msg7]
Assign (o10)
[in: msg5, out: msg6]
Invoke (o11)
[service s2, in: msg6, out: msg7]
Join (o9)
[in: msg5,msg7, out: msg9]
INNER
A1_Productkey
> 9000000
Join (o13)
[in: msg5,msg7, out: msg8]
Switch (o12)
[in: msg7]
INNER
INNER
Join (o14)
[in: msg5,msg7, out: msg8]
Assign (o15)
[in: msg8, out: msg9]
Reply (o16)
[in: msg9]
Figure 2.10: Example Integration Flow – Plan P 4
We receive a message from the external system s 5 (eCommerce). Subsequently, we query
the ERP system in order to determine if this user-defined product has already been sold. If
this is the case, we query the SCM system and join those possible products with the basic
information. Otherwise, we query the Material system in order to determine the costs of
a newly created product. Finally, we prepare the answer in the sense of a cost estimate
and send a reply message to the customer (who was blocked during execution).
To summarize, the plans P 1 , P 2 , and P 4 are data-driven integration flows, while the
plan P 3 is a periodically (time-based) initiated integration flow. Furthermore, the plans
P 1 , P 2 , and P 3 are executed asynchronously (where for P 1 and P 2 inbound queues are
used), while the plan P 4 is executed synchronously (where the client system is blocked).
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