Hi, Before adding the partitioner all your functions are chained together. That is, everything is executed in one Thread and sending elements from one function to the next is essentially just a method call. By introducing a partitioner you break this chain and therefore your job now has to send data (at least) across between different Threads. I think you should see this if you look at the execution graph.
Best, Aljoscha > On 15. Jun 2017, at 14:35, sohimankotia <sohimanko...@gmail.com> wrote: > > Hi, > > I have streaming job which is running with parallelism 1 as of now . (This > job will run with parallelism > 1 in future ) > > So I have added custom partitioner to partition the data based on one tuple > field . > > The flow is : > > source -> map -> partitioner -> flatmap -> sink > > The partitioner is adding around 40 sec or more delay for 40% of data (from > map to flatmap ). > > I am not able to understand if parallelism is one how this delay is getting > added . > > > > -- > View this message in context: > http://apache-flink-user-mailing-list-archive.2336050.n4.nabble.com/Using-Custom-Partitioner-in-Streaming-with-parallelism-1-adding-latency-tp13766.html > Sent from the Apache Flink User Mailing List archive. mailing list archive at > Nabble.com.