HI Piotrek, Yes, to be more clear, 1) the network I/O issue I am referring to is in between Flink and external sink. We did not see issues in between operators. 2) yes we've considered rate limiting sink functions as well which is also mentioned in the doc. along with some of the the pro-con we identified.
This kind of problem seems to only occur in WindowOperator so far, but yes it can probably occur to any aligned interval based operator. -- Rong On Wed, Sep 26, 2018 at 11:44 PM Piotr Nowojski <pi...@data-artisans.com> wrote: > Hi, > > Thanks for the proposal. Could you provide more > background/explanation/motivation why do you need such feature? What do you > mean by “network I/O” degradation? > > On it’s own burst writes shouldn’t cause problems within Flink. If they > do, we might want to fix the original underlying problem and if they are > causing problems in external systems, we also might think about other > approaches to fix/handle the problem (write rate limiting?), which might be > more general and not fixing only bursts originating from WindowOperator. > I’m not saying that your proposal is bad or anything, but I would just like > to have more context :) > > Piotrek. > > > On 26 Sep 2018, at 19:21, Rong Rong <walter...@gmail.com> wrote: > > > > Hi Dev, > > > > I was wondering if there's any previous discussion regarding how to > handle > > burst network I/O when deploying Flink applications with window > operators. > > > > We've recently see some significant network I/O degradation when trying > to > > use sliding window to perform rolling aggregations. The pattern is very > > periodic: output connections get no traffic for a period of time until a > > burst at window boundaries (in our case every 5 minutes). > > > > We have drafted a doc > > < > https://docs.google.com/document/d/1fEhbcRgxxX8zFYD_iMBG1DCbHmTcTRfRQFXelPhMFiY/edit?usp=sharing > > > > on > > how we proposed to handle it to smooth the output traffic spikes. Please > > kindly take a look, any comments and suggestions are highly appreciated. > > > > -- > > Rong > >
