Kishore It sounds like the solution is to set the constraints so that only one transition at a time. Can you point me to an example of how to do this? Also is this something I can set in the JSON file?
Sent from my iPad On Apr 1, 2013, at 11:32 AM, kishore g <[email protected]> wrote: > Hi Ming, > > Thanks for the detailed explanation. Actually 5 & 6 happen in parallel, > Helix tries to parallelize the transitions as much as possible. > > There is another feature in Helix that allows you to sort the transitions > based on some priority.See STATE_TRANSITION_PRIORITY_LIST in state model > definition. But after sorting Helix will send as many as possible in parallel > without violating constraints. > > In your case you want the priority to be S-M, O-S, M-S but that is not > sufficient since O-S and M-S will be sent in parallel. > > Additionally, what you need to do is set contraint on transition that there > should be only one transition per partition at any time. This will basically > make the order 6 5 7 and they will be executed sequentially per partition. > > We will try this out and let you know, you dont need to change any code in > Helix or your app. You should be able to tweak the configuration dynamically. > > We will try to think of solving this in a more elegant way. I will file a > jira and add more info. > > I also want to ask this question, when a node comes up if it is mandatory to > talk to MASTER what happens when the nodes are started for the first time or > when all nodes crash and come back. > > thanks, > Kishore G > > > > > > >
