Replaying of tuples is done from the Spout and not done on a point to point basis like Apache Flume.
Either a tuple is completely processed i.e. acked by every single bolt in the pipeline or it's not; if it's not then it will be replayed by the Spout (if the Spout implements a replay logic when the fail() method is called) Acking has to be done at every stage of the pipeline. Here's a post that will explain you the necessary details of the XoR Ledger: https://bryantsai.com/fault-tolerant-message-processing-in-storm/ On Wed, Nov 30, 2016 at 9:10 PM, Navin Ipe <navin....@searchlighthealth.com> wrote: > Apart from the previous question, there's also the question of whether we > should ack the tuple in execute() of Bolt1? Or is it just sufficient to ack > it in Bolt2? > > > On Wed, Nov 30, 2016 at 12:28 PM, Navin Ipe <navin.ipe@searchlighthealth. > com> wrote: > >> Hi, >> >> Just need a confirmation for this topology: >> >> *Spout* ---emit---> *Bolt1* ---emit---> *Bolt2* >> >> Spout is BaseRichSpout. Bolt1 and Bolt2 are BaseRichBolt. >> Spout emits just one tuple per nextTuple() call. >> Bolt1 anchors to the tuple it received from Spout and emits many >> different tuple objects. >> >> If any of the emits of Bolt1 fails, is there no way for Bolt 1 to re-emit >> the tuple? Do I have to wait for the topology to figure out that one of >> Bolt1's tuples failed and then do a re-emit from the Spout? >> >> -- >> Regards, >> Navin >> > > > > -- > Regards, > Navin >
