Hi Jihyoun, PE graphs with cycles can certainly get a bit tricky sometimes, but mainly because they can lead to deadlocks.
I don't see how you'd lose events in the case you present if you don't lose or reconfigure nodes. In the very specific case of sending an event from PE instance a1 to the same PE instance a1, the event is simply put in an in-memory blocking queue. It would be great to understand in which conditions you can see this issue. Could you be more specific? (I can't reproduce that with simple tests, but I don't have your own settings/code/environment). Thanks, Matthieu On Feb 20, 2013, at 03:04 , JiHyoun Park wrote: > Dear Matthieu > > I also experienced the same problem with Gowtham. > Unlike him, I created a downstream to itself with only one key. (It was like > a flag to be turned on/off.) > I tested it and found sometimes one PE instance does not receive the event. > I remember that it didn't depend on a specific node. > > At the time, I also wondered why. > Since it's a very simple logic, you can test it by yourself without much > efforts. > It would be really appreciated if you can tell us the solution or at least > the reason. > > Best Regards > Jihyoun > > > > On Tue, Feb 19, 2013 at 11:38 PM, Matthieu Morel <mmo...@apache.org> wrote: > Hi, > > Can you provide more detail about a node not running correctly? what does > that mean to you, that it does not receive messages? Maybe that's normal > because of the distribution of keys. Or maybe you only have 3 active nodes in > the cluster. (you can check that with the s4 status tool) > > The distribution of keys across nodes is a simple hash+mod , which you can > override if needed. > > I would recommend to check whether all data is processed as expected, > regardless of the location. > > Let us know, > > thanks, > > Matthieu > > > On Feb 19, 2013, at 16:27 , Gowtham S wrote: > >> Hi S4 community, >> >> I have been working with s4 piper for 3 months. now i am just trying to make >> a downstream from a PE to the same PE with different Key Id. >> >> i just have a scenario in which i would have an unique PE whose downstream >> is also to that PE but each time the Key Id of the targeted PE may vary. >> this continues until it satisfies a condition where it just stops. >> >> i started implementing this in a single machine with 4 nodes, as i had 4 >> different keys for that unique PE(say 0,1,2,3). so now every node will have >> that PE clone with one individual key Id from the available Key Ids. one PE >> may send some events to PE in other nodes , until certain condition is >> reached where the process is stopped. >> >> now three nodes are running correctly except one node.. i wonder why .. >> because all the nodes have same computational part to execute. >> >> please help me as how s4 deals while assigning a single PE to different >> nodes with different key Id .. >> >> >> >> >> >> >> On Tue, Feb 19, 2013 at 8:22 PM, Gowtham S <seldomgowt...@gmail.com> wrote: >> Hi S4 community, >> >> > >
