16.2Measure downstream calls

For each important external dependency, collect something conceptually like:

dependency = Salesforce
operation  = upsert-account
duration   = 387 ms
status     = SUCCESS

and:

dependency = Billing
operation  = get-balance
duration   = 4218 ms
status     = TIMEOUT

Then if p95 API latency jumps:

500 ms → 5 sec

you can determine:

Mule CPU stable
Salesforce stable
Billing p95 jumped to 4.5 sec

Much more useful.