Previous – Detour | Index | Next – Message History

This week, we’ll study the next system management pattern known as Wire Tap.

When do I use this pattern?

Wire Tap pattern is used to listen into Point-to-Point communication, generally, to measure the performance of communication or to prepare reports based on the content of the message. Wire Tap is implemented using a Recipient List where recipients include the intended receiver and the component that wants to measure performance.

Wire Tap in CPI

For demonstration, we’ll send the orders from Orders Management System to ECC and also send it to the reporting software.

Integration Flow

Processing an Order

This simple flow exposes the Order Creation in ECC using HTTPS Sender Adapter. The IDoc is created in ECC using IDoc Receiver Adapter. For simplicity, the assumption is that the consumer will send an IDoc.

In between the sender and receiver, there is a Parallel Multicast. The Parallel Multicast sends the inbound IDoc to ECC and to the Reporting software without changing the contents.

Here, the OMS to ECC is the main flow, whereas, the Reporting system is tapping into the wire connecting the OMS to ECC.

This implementation does not let the system administrators turn off the Wire Tap using a Control Bus. We can simply add a Detour to enable control from the Control Bus like so:

Processing an Order with Control Bus

In this flow, we have added ‘Wire Tap?’ router to toggle sending the inbound IDoc to Reporting System.

EIPinCPI Rating – 7/10

CPI does not provide out of the box component to implement a Wire Tap. The implementation discussed here has a disadvantage that if the Reporting system is causing an error, it will show up in the monitoring. Therefore, the rating for implementation of Wire Tap pattern is 7 out of 10.

Conclusion

Wire Tap is used to inspect the message in Point-to-Point communication.

References/Further Readings

• Wire Tap Pattern in Enterprise Integration Patterns
• EIPinCPI
  • Recipient List
  • Control Bus
• CPI Components
  • HTTPS Sender Adapter
  • IDoc Receiver Adapter
  • Parallel Multicast

Hope this helps,
Bala

Previous – Detour | Index | Next – Message History