What is “Outbound Transaction” in layman terms?

Question

We are going to build WCF services based on SOA. During a meeting recently, client explained the new system environment. He used the word “outbound transaction”. Due to time limitations, I could not get it clarified. Then I made some search in internet. However it leads me to different topics.

So, my question is - what is “Outbound Transaction” in the context of “service orientation”? Can you give an example?

READING:

1. What is SOA "in plain english"?

2. What is a "web service" in plain English?

3. WCF, DataPower integration - secure binding necessary?

Rare

I think you should ask the speaker to clarify, really, but: personally I start to get very worried when people start talking about transactions in the context of WCF/SOA - can get very sticky. – Pertain

Answer 1

For the sake of your project, make sure you do as @Marc suggests and follow up with the client.

But, in general terms, for asynchronous or batch type communication

• Inbound message - the flow of the message comes into YOUR system
• Outbound message - the flow of the message flows out of YOUR system.

(obviously the direction of inbound / outbound depends on the point of view of the system or esb / eai hub - system architects on the other side of the interface will see things the other way around)

The word transaction might mean many things:

1. ACID Transactions (Single phase, e.g. SQL BEGIN TRAN, or Two Phase e.g. XA/DTC)
2. Compensated / Long running transactions (usually in context of a ESB or EAI or BPEL engine)
3. The data flowing between systems contains Financial transactions (i.e. business domain context, nothing to do with XA / DTC / SQL transactions at all)

Admittedly

The word transaction could be misused as a word to just mean communication. I am not saying its a correct term to use in this context, but in conversations the mouth can sometimes run faster than the brain. – Habana

Answer 2

Say suppose you are providing a service to a consumer say A and in some part of your service you are depending on some other service provider which is providing a service B to complete your service and give the final output to the consumer. so in this case the point of contact from service A to service B (external system) is know as outbound transaction.

Nichol