On Wed, Apr 19, 2017 at 6:43 AM, 风驰天下 <609790...@qq.com> wrote:
> Thanks for your reply. > > "I'm not exactly sure of what you mean by "the cluster always run in only > one datacenter". You're actually setting up a 6-node cluster with 3 of > them as non-voting and acting as a backup - they are replicated to but are > not needed for consensus. " > > --I'm not sure how many datacenter the 6 nodes distribute. One or two? > I'm just referring to controller nodes. The use case where we've deployed geo-clustering is 2 3-node clusters brought together into a single 6-node cluster with one 3-node serving as a DR backup. > --Can you tell me the difference between voting node and non-voting node? > A non-voting node is replicated to but doesn't participate in raft consensus, ie it's not needed nor counted for consensus. It also doesn't participate in leader elections and thus cannot become the leader. Thus a a non-voting node is strictly a backup. > Best regards, > Simpler > > > ------------------ 原始邮件 ------------------ > *发件人:* "Tom Pantelis";<tompante...@gmail.com>; > *发送时间:* 2017年4月19日(星期三) 下午5:01 > *收件人:* "风驰天下"<609790...@qq.com>; > *抄送:* "odl"<controller-dev@lists.opendaylight.org>; > *主题:* Re: [controller-dev] Question about Geo-distributed > Active/BackupSetup in Carbon > > > On Wed, Apr 19, 2017 at 4:04 AM, 风驰天下 <609790...@qq.com> wrote: > >> Hi,everyone, >> >> I have two question about Geo-distributed Active/Backup Setup in >> Carbon. >> >> 1.It is said that the cluster can be expanded with nodes in a >> different datacenter, but in a way that doesn’t affect latency of the >> primary nodes, which I think means I can setup a backup cluster for a >> cluster running in another datacenter and actully the cluster always run in >> only one datacenter? >> > > I'm not exactly sure of what you mean by "the cluster always run in only > one datacenter". You're actually setting up a 6-node cluster with 3 of > them as non-voting and acting as a backup - they are replicated to but are > not needed for consensus. > > >> >> 2.It is mentioned that the voting state change is sent to any single >> cluster node by rpc request. But after that it is said that the leader >> persists >> the voting changes and replicates them to the remaining nodes, so the >> voting state change rpc is only carried out once on any cluster node or all >> cluster nodes? >> > > You only need to send the RPC once to one node - if it's not the leader, > it will forward to the leader. > > > >> >> Best regards, >> Simpler >> >> _______________________________________________ >> controller-dev mailing list >> controller-dev@lists.opendaylight.org >> https://lists.opendaylight.org/mailman/listinfo/controller-dev >> >> >
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