Re: Backpressure and 99th percentile latency

2020-03-09 Thread Felipe Gutierrez
Indeed, it is a bit tricky to understand the relation between floatingBuffersUsage, exclusiveBuffersUsage. I am reading again that table on (https://flink.apache.org/2019/07/23/flink-network-stack-2.html) but I guess I can rely on the latency metric that I implemented on my operator (not the defaul

Re: Backpressure and 99th percentile latency

2020-03-07 Thread Zhijiang
Thanks for the feedback Felipe! Regarding with your below concern: > Although I think it is better to use outPoolUsage and inPoolUsage according > to [1]. However, in your opinion is it better (faster to see) to use > inputQueueLength and > outputQueueLength or outPoolUsage and inPoolUsage to m

Re: Backpressure and 99th percentile latency

2020-03-06 Thread Felipe Gutierrez
Thanks for the clarified answer @Zhijiang, I am gonna monitor inputQueueLength and outputQueueLength to check some relation with backpressure. Although I think it is better to use outPoolUsage and inPoolUsage according to [1]. However, in your opinion is it better (faster to see) to use inputQueueL

Re: Backpressure and 99th percentile latency

2020-03-05 Thread Arvid Heise
Hi Felipe, latency under backpressure has to be carefully interpreted. Latency's semantics actually require that the data source is read in a timely manner; that is, there is no bottleneck in your pipeline where data is piling up. Thus, to measure latency in experiments you must ensure that the c

Re: Backpressure and 99th percentile latency

2020-03-05 Thread Zhijiang
Hi Felipe, Try to answer your below questions. > I understand that I am tracking latency every 10 seconds for each physical > instance operator. Is that right? Generally right. The latency marker is emitted from source and flow through all the intermediate operators until sink. This interval c