3rd Party Event Tracing Calls in Apigee

Apigee has information on their website which makes event tracing of calls to a 3rd party system relatively easy. But, the information is spread out over a couple of pages. To provide this functionality effectively, you’ll want to use two different features together:

• Use a PostClientFlow to ensure the event logging is performed after the response is sent to the client.
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• Use a ServiceCallout Policy, with the <Response /> element removed. This will ensure the call to the 3rd party system is done as a Fire-and-Forget call, rather than one that waits for a response before continuing processing.
  
  There is a MessageLogging Policy, which is specifically designed for this logging scenario. However, the MessageLogging policy doesn’t allow for Header information to be added into the call; and there are a number of 3rd party logging systems (like Splunk) which use the Authentication header to verify the incoming caller.

The end result of making these changes looks a little like this:

The 5 steps within the workflow taht are grouped by a red box show a group of 2 service calls which are each logging to separate 3rd party systems (we wanted to compare the two products to see which would fit our needs better). In the top left red box is the complete processing time within Apigee, 78 ms. And the small red box at the bottom right (in Postman) is the amount time from the client’s perspective, just 46 ms.

To do this, you’ll want to setup a shared flow that will make the ServiceCallout's. Remember that each ServiceCallout should remove it’s <Response> element:

Once that’s in place, you’ll just need use the shared flow as part of a <PostClientFlow> within you API’s. I wish this was an element I could use within the Post-proxy Flow Hook; that way I could add it to all APIs in one place.