Hi, in Flink the accumulators/aggregators are not faul-tolerant. In case of a failure the job will be restarted but the accumulators will start from scratch. Initially they were only meant as a rough way to gauge the progress that a job is making. People should not rely on them for accurate numbers right now.
Cheers, Aljoscha > On 21 Mar 2016, at 20:37, William McCarthy <[email protected]> wrote: > > Hi, > > I just had a look at the capability matrix here: > http://beam.incubator.apache.org/capability-matrix/ . I really like it, as it > gives a nice summary of the current state of implementation completeness for > the different runners. > > I had one follow-up question, regarding the cell at the intersection of the > Aggregators row and the Apache Flink column, with this content: "In streaming > mode, Aggregators may undercount”. Can you give me some ideas about what this > means? In what circumstances might this happen? Are there some mitigation > strategies that are appropriate? > > Thanks, > > Bill
