> ... do you mean using client.admin().setConfiguration on the RaftServer?
Yes. > ... do we have to run this setConfiguration with updated configuration for the existing running servers to update the peers list? The setConfiguration RPC is for the entire Raft service but not for individual servers. We should invoke client.admin().setConfiguration once. Then, the RPC will be automatically sent to the Leader and the Leader will propagate it to the Followers. This is similar to client.async().send(message). Tsz-Wo On Fri, Aug 5, 2022 at 10:47 AM Swapnil Tailor <[email protected]> wrote: > when you say use setConfiguration, do you mean using > client.admin().setConfiguration on the RaftServer? And do we have to run > this setConfiguration with updated configuration for the existing running > servers to update the peers list? > > On Thu, Aug 4, 2022 at 9:40 AM Tsz Wo Sze <[email protected]> wrote: > >> Use setContfiguration to set the peer list to [B, C, D]. And then start >> server D with a peer list [B, C, D] and the same group id. >> >> Tsz-Wo >> >> >> On Thu, Aug 4, 2022 at 9:31 AM Swapnil Tailor <[email protected]> >> wrote: >> >>> ok now if server A goes down and a new server D joins the raft server >>> peer, how can that update should happen so everyone (RaftServer and >>> RaftClient) is aware of the new peer? >>> >>> On Thu, Aug 4, 2022 at 9:28 AM Tsz Wo Sze <[email protected]> wrote: >>> >>>> > 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 >>>>>>>>>> >>>>>>>>>
