help with dynamically modifying request data

[Rabi Lahiri <ra...@gmail.com>]

Hi,
I have a testing requirement I'm not quite sure how to fulfill. We have a 
large stream of recorded HTTP requests to our service that we want to replay 
to do capacity testing. We have a mix of APIs and for most of them we simply 
want to replay exactly what is in the input file. However, for a few APIs, 
we need to insert a corresponding service call immediately preceding the API 
call and then use the response in the original request.

For example:
API insertN requires an id parameter which the client would have obtained 
from API getNewN. Our recorded stream of calls has old, invalid id numbers 
for all of the insert calls. If the input stream we have is like this 
(assume all id numbers <100 are old and invalid):

insert1(id=10);
insert2(id=20);
insert3(id=30);

We can't replay these exactly because ids 10,20 and 30 already exist in our 
database. What we need is:

getNew1; <- returns id=100
insert1(id=100); <- id 10 replaced with 100 dynamically
getNew2; <- returns id=110
insert2(id=110); <- id 20 replaced with 110
getNew3; <- returns id=120
insert3(id=120); <- id 30 replaced with 120


I think I could do this if these were the only APIs we had in our test run, 
but the insert calls are intermixed with many other APIs that we want to 
replay without modifying. Can I do this utilizing existing JMeter 
functionality or is it likely that I'll have to modify some code?

thanks,
Rabi Lahiri