Re: Re[2]: [KUDU] Rebalancing tool
Yeah, it's worth looking into. If leadership tends to migrate to a subset of the servers it indicates some kind of instability or communication problems with the other servers, since leadership will move away from servers that have trouble sending timely heartbeats to followers. The leader does do more work for a tablet than the followers, and writes must go into the leader's log as well as the log of a majority, so there's some penalty on write latency and throughput to have leadership concentrated. The next version of Kudu will have an enhanced leader_step_down tool that implements KUDU-2245, so leadership can be transferred with minimal disruption to the tablet and it can be transferred to a specific replica (as long as that replica is almost caught up to the leader). -Will On Tue, Dec 4, 2018 at 5:04 AM Дмитрий Павлов wrote: > Thank Will > > So i have one more question. > > is this (i mean leaders skew) something i should be concerned about? > In terms of load balancing for example in case if i use kudu 1.8.0 with > spark > > Regards Dmitry Pavlov > > > Вторник, 4 декабря 2018, 0:10 +03:00 от William Berkeley < > wdberke...@cloudera.com>: > > Yes, it's expected. The rebalancing tool does not balance leadership. In > fact, it tries to avoid relocating leader replicas because the tool wants > to minimize the disturbance to the cluster. It will relocate leader > replicas if it has to, but it won't make any attempt to balance them. > > You can use 'kudu tablet leader_step_down' to force the leader replica of > a tablet to step down. A new leader will be elected after the election > timeout passes. It's not guaranteed that the old leader won't be reelected. > > -Will > > On Mon, Dec 3, 2018 at 4:11 AM Дмитрий Павлов <https://e.mail.ru/compose/?mailto=mailto%3adm.pav...@inbox.ru>> wrote: > > > Hi guys > > I have a question about Kudu rebalancing tool (*kudu cluster rebalance*). > > So my situation is following: > > When our kudu cluster has been updated to version 1.8.0 i ran *kudu > cluster rebalance *for one table. > After that i checked per-table replica distribution and it looks fine but > leaders distributions per nodes still not good for my table > > Is it expected behaviour for rebalancing tool? > > Regards, Dmitry Pavlov > > > > > > -- > Дмитрий Павлов >
Re[2]: [KUDU] Rebalancing tool
Thank Will So i have one more question. is this (i mean leaders skew) something i should be concerned about? In terms of load balancing for example in case if i use kudu 1.8.0 with spark Regards Dmitry Pavlov >Вторник, 4 декабря 2018, 0:10 +03:00 от William Berkeley >: > >Yes, it's expected. The rebalancing tool does not balance leadership. In fact, >it tries to avoid relocating leader replicas because the tool wants to >minimize the disturbance to the cluster. It will relocate leader replicas if >it has to, but it won't make any attempt to balance them. > >You can use 'kudu tablet leader_step_down' to force the leader replica of a >tablet to step down. A new leader will be elected after the election timeout >passes. It's not guaranteed that the old leader won't be reelected. > >-Will >On Mon, Dec 3, 2018 at 4:11 AM Дмитрий Павлов < dm.pav...@inbox.ru > wrote: >> >>Hi guys >> >>I have a question about Kudu rebalancing tool ( kudu cluster rebalance ). >> >>So my situation is following: >> >>When our kudu cluster has been updated to version 1.8.0 i ran kudu cluster >>rebalance for one table. >>After that i checked per-table replica distribution and it looks fine but >>leaders distributions per nodes still not good for my table >> >>Is it expected behaviour for rebalancing tool? >> >>Regards, Dmitry Pavlov >> >> >> -- Дмитрий Павлов
Re: [KUDU] Rebalancing tool
Yes, it's expected. The rebalancing tool does not balance leadership. In fact, it tries to avoid relocating leader replicas because the tool wants to minimize the disturbance to the cluster. It will relocate leader replicas if it has to, but it won't make any attempt to balance them. You can use 'kudu tablet leader_step_down' to force the leader replica of a tablet to step down. A new leader will be elected after the election timeout passes. It's not guaranteed that the old leader won't be reelected. -Will On Mon, Dec 3, 2018 at 4:11 AM Дмитрий Павлов wrote: > > Hi guys > > I have a question about Kudu rebalancing tool (*kudu cluster rebalance*). > > So my situation is following: > > When our kudu cluster has been updated to version 1.8.0 i ran *kudu > cluster rebalance *for one table. > After that i checked per-table replica distribution and it looks fine but > leaders distributions per nodes still not good for my table > > Is it expected behaviour for rebalancing tool? > > Regards, Dmitry Pavlov > > > >
[KUDU] Rebalancing tool
Hi guys I have a question about Kudu rebalancing tool ( kudu cluster rebalance ). So my situation is following: When our kudu cluster has been updated to version 1.8.0 i ran kudu cluster rebalance for one table. After that i checked per-table replica distribution and it looks fine but leaders distributions per nodes still not good for my table Is it expected behaviour for rebalancing tool? Regards, Dmitry Pavlov
答复: [KUDU] Rebalancing
https://kudu.apache.org/releases/1.8.0/docs/release_notes.html#rn_1.8.0_new_features 何李夫 2018-11-27 19:11:25 发件人: user-return-1542-hzhelifu=corp.netease@kudu.apache.org 代表 Дмитрий Павлов 发送时间: 2018年11月27日 18:57 收件人: user 主题: [KUDU] Rebalancing Hi Does last version of Kudu support auto rebalancing between nodes? Best Regards, Dmitry Pavlov
[KUDU] Rebalancing
Hi Does last version of Kudu support auto rebalancing between nodes? Best Regards, Dmitry Pavlov
