Regarding Sub transaction
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We have a scenario, where we are trying to get the consolidate response time of some transactions(actions). So, we are using Sub transaction for these actions. But, there is a difference between the response time of the main transaction and sum of response time of sub transactions. Is there any other way of consolidating the response time of some actions.
Re: Regarding Sub transaction
One thing I can think of as soon as I read your problem is that your overall transaction might be timing the wasted time between the sub-transactions also which might be causing your overall transaction to report slightly higher time as compared to the total of your individual sub-transactions.
The alternate way I can think of for timing individual actions is by using timers. Use the functions lr_start_timer and lr_end_timer along with your actions to time the individual actions and use it in the place where you need it.