> Yes they do have same group id. That is good.
> ... Serve A could have peer list: [A, B], and Server B could have peer list: [B, C] ... In this case, all servers A, B and C must have the same peer list [A, B, C] when they start up. Tsz-Wo On Wed, Aug 3, 2022 at 10:10 PM Swapnil Tailor <[email protected]> wrote: > You can take a look at the code here: > https://github.com/prestodb/presto/pull/17915 > > On Wed, Aug 3, 2022 at 5:55 PM Swapnil Tailor <[email protected]> > wrote: > >> Yes they do have same group id. >> >> On Wed, Aug 3, 2022, 4:35 PM Tsz Wo Sze <[email protected]> wrote: >> >>> Hi Swapnil, >>> >>> We should use the same group configuration (i.e. the same set of >>> servers) to start up the servers. Otherwise, there is no way to compute >>> "majority" correctly. >>> >>> BTW, they should also have the same group id. Are they? >>> >>> Tsz-Wo >>> >>> >>> On Wed, Aug 3, 2022 at 1:54 PM Swapnil Tailor <[email protected]> >>> wrote: >>> >>>> Yes all the servers are having the same RaftGroup but the peer list >>>> could be different (i.e. Serve A could have peer list: [A, B], and Server B >>>> could have peer list: [B, C]). >>>> Reason they won't see all the servers up at the same time. And that's >>>> why we want to know if we can add the other peers in the raft group later >>>> after the server start up. And what is the right way of doing that. >>>> >>>> On Wed, Aug 3, 2022 at 1:44 PM Tsz Wo Sze <[email protected]> wrote: >>>> >>>>> Hi Swapnil, >>>>> >>>>> Thanks for trying Ratis! >>>>> >>>>> Are they starting with the same RaftGroup? All servers A, B and C >>>>> should have the same RaftGroup(A, B, C) when they start up. >>>>> >>>>> Tsz-Wo >>>>> >>>>> On Wed, Aug 3, 2022 at 1:32 PM Swapnil Tailor < >>>>> [email protected]> wrote: >>>>> >>>>>> Hello, >>>>>> >>>>>> We are trying to use ratis library to our existing Presto Distributed >>>>>> query engine. We are facing one issue while working on updating the peers >>>>>> in the cluster: >>>>>> >>>>>> Ratis Server runs on multiple resource managers, and it takes time >>>>>> for them to get up and join the cluster. So we require the Ratis server >>>>>> to >>>>>> have atleast 2 server before it starts the server. This works well. But >>>>>> the >>>>>> issue happens in the leader selection as mentioned below: >>>>>> 1. There are 3 ratis servers in the cluster, A, B, C >>>>>> 2. With server A seeing serve B, the minimum server count matches and >>>>>> it starts the server with peers list as A, B >>>>>> 3. Now when server C starts, we try to update the peer list using >>>>>> client api: >>>>>> RaftClient.admin().setContfiguration(updated peer list), but >>>>>> for some reason this is not working correctly and there are multiple >>>>>> leaders getting elected in the cluster. >>>>>> >>>>>> Can someone help understand how should we fix that? And also if the >>>>>> peer updation logic is correct by each server running RaftClient and >>>>>> update >>>>>> the configuration as and when it sees the peer list has changes (i.e. a >>>>>> new >>>>>> server joins the cluster/existing one dies/replaced). >>>>>> >>>>>> Also side question: Can someone invite me to the slack channel to be >>>>>> part of the community? >>>>>> >>>>>> Thanks in advance, >>>>>> Swapnil >>>>>> >>>>>
