Hello,
As for 1), my suspicion is that this is caused by chaining. If the map
function is chained to the kafka source then the latency markers are
always immediately forwarded, regardless of what your map function is doing.
If the map function is indeed chained to the source, could you try again
after disabling the chain by calling `X.map(...).createNewChain()` and
report back?
As for 2), I don't think this is possible right now.
Regards,
Chesnay
On 17.07.2017 12:42, Paolo Cristofanelli wrote:
Hi,
I would like to understand how to measure the latency of a record.
I have set up a simple project with a Kafka consumer that reads from a
topic and performs a simple map (with a thread sleep inside).
In order to measure the latency of this mapper I have added
env.getConfig().setLatencyTrackingInterval(10);
After that, I was planning to access the latency through the webUI
interface but the related graph does not show any values.
I do not understand why. I was thinking that I in the graph I should
observe at least the sleep duration.
I also have another question:
I am using a count window, aggregating every 100 input records and
then I perform a map. I want to see the latency as the difference
between the time at which the output record is emitted and the arrival
time of the earliest input record.
For example, the first value arrives at x. After x +5 I all the 100
values arrived and the system can aggregate them. Now I perform the
map operation and we emit the output record at time x+15.
I would like to obtain 15 as latency.
Do you have any suggestion on how to proceed?
Thanks for your time,
Paolo Cristofanelli
