Yes! It works! I have tested RebalanceLeaders today with the patch provided by Endika Posadas. (http://lucene.472066.n3.nabble.com/Rebalance-Leaders-Leader-node-deleted-when-rebalancing-leaders-td4417040.html) And at last it works as expected on my collection with 5 nodes and about 400 shards. Original patch was slightly incompatible with 7.6.0 I hope this patch will help to try this feature with 7.6 https://drive.google.com/file/d/19z_MPjxItGyghTjXr6zTCVsiSJg1tN20
RebalanceLeaders was not very useful feature before 7.0 (as all replicas were NRT) But new replica types made it very helpful to keep big clusters in order... I wonder, why there is no any jira about this case (or maybe I missed it)? Anyone who cares, please, help to create jira and improve this feature in the nearest releaase -- Vadim > -----Original Message----- > From: Vadim Ivanov [mailto:vadim.iva...@spb.ntk-intourist.ru] > Sent: Friday, December 07, 2018 6:13 PM > To: solr-user@lucene.apache.org > Subject: RE: REBALANCELEADERS is not reliable > > I'm waiting for 7.6 or 7.5.1 and plan to apply patch from Endika Posadas to > it. > Then test again and hope it'll help > -- > Vadim > > > > -----Original Message----- > > From: Bernd Fehling [mailto:bernd.fehl...@uni-bielefeld.de] > > Sent: Friday, December 07, 2018 12:01 PM > > To: solr-user@lucene.apache.org > > Subject: Re: REBALANCELEADERS is not reliable > > > > Thanks for looking this up. > > It could be a hint where to jump into the code. > > I wonder why they rejected a jira ticket about this problem? > > > > Regards, Bernd > > > > Am 06.12.18 um 16:31 schrieb Vadim Ivanov: > > > Is solr-dev forum I came across this post > > > http://lucene.472066.n3.nabble.com/Rebalance-Leaders-Leader-node- > > deleted-when-rebalancing-leaders-td4417040.html > > > May be it will shed some light? > > > > > > > > >> -----Original Message----- > > >> From: Atita Arora [mailto:atitaar...@gmail.com] > > >> Sent: Thursday, November 29, 2018 11:03 PM > > >> To: solr-user@lucene.apache.org > > >> Subject: Re: REBALANCELEADERS is not reliable > > >> > > >> Indeed, I tried that on 7.4 & 7.5 too, indeed did not work for me as > > >> well, > > >> even with the preferredLeader property as recommended in the > > >> documentation. > > >> I handled it with a little hack but certainly this dint work as expected. > > >> I can provide more details if there's a ticket. > > >> > > >> On Thu, Nov 29, 2018 at 8:42 PM Aman Tandon > > >> <amantandon...@gmail.com> wrote: > > >> > > >>> ++ correction > > >>> > > >>> On Fri, Nov 30, 2018, 01:10 Aman Tandon <amantandon...@gmail.com > > >> wrote: > > >>> > > >>>> For me today, I deleted the leader replica of one of the two shard > > >>>> collection. Then other replicas of that shard wasn't getting elected > > >>>> for > > >>>> leader. > > >>>> > > >>>> After waiting for long tried the setting addreplicaprop preferred > > >>>> leader > > >>>> on one of the replica then tried FORCELEADER but no luck. Then also > > tried > > >>>> rebalance but no help. Finally have to recreate the whole collection. > > >>>> > > >>>> Not sure what was the issue but both FORCELEADER AND > REBALANCING > > >> didn't > > >>>> work if there was no leader however preferred leader property was > > setted. > > >>>> > > >>>> On Wed, Nov 28, 2018, 12:54 Bernd Fehling < > > >>> bernd.fehl...@uni-bielefeld.de > > >>>> wrote: > > >>>> > > >>>>> Hi Vadim, > > >>>>> > > >>>>> thanks for confirming. > > >>>>> So it seems to be a general problem with Solr 6.x, 7.x and might > > >>>>> be still there in the most recent versions. > > >>>>> > > >>>>> But where to start to debug this problem, is it something not > > >>>>> correctly stored in zookeeper or is overseer the problem? > > >>>>> > > >>>>> I was also reading something about a "leader queue" where possible > > >>>>> leaders have to be requeued or something similar. > > >>>>> > > >>>>> May be I should try to get a situation where a "locked" core > > >>>>> is on the overseer and then connect the debugger to it and step > > >>>>> through it. > > >>>>> Peeking and poking around, like old Commodore 64 days :-) > > >>>>> > > >>>>> Regards, Bernd > > >>>>> > > >>>>> > > >>>>> Am 27.11.18 um 15:47 schrieb Vadim Ivanov: > > >>>>>> Hi, Bernd > > >>>>>> I have tried REBALANCELEADERS with Solr 6.3 and 7.5 > > >>>>>> I had very similar results and notion that it's not reliable :( > > >>>>>> -- > > >>>>>> Br, Vadim > > >>>>>> > > >>>>>>> -----Original Message----- > > >>>>>>> From: Bernd Fehling [mailto:bernd.fehl...@uni-bielefeld.de] > > >>>>>>> Sent: Tuesday, November 27, 2018 5:13 PM > > >>>>>>> To: solr-user@lucene.apache.org > > >>>>>>> Subject: REBALANCELEADERS is not reliable > > >>>>>>> > > >>>>>>> Hi list, > > >>>>>>> > > >>>>>>> unfortunately REBALANCELEADERS is not reliable and the leader > > >>>>>>> election has unpredictable results with SolrCloud 6.6.5 and > > >>>>>>> Zookeeper 3.4.10. > > >>>>>>> Seen with 5 shards / 3 replicas. > > >>>>>>> > > >>>>>>> - CLUSTERSTATUS reports all replicas (core_nodes) as state=active. > > >>>>>>> - setting with ADDREPLICAPROP the property preferredLeader to > > other > > >>>>> replicas > > >>>>>>> - calling REBALANCELEADERS > > >>>>>>> - some leaders have changed, some not. > > >>>>>>> > > >>>>>>> I then tried: > > >>>>>>> - removing all preferredLeader properties from replicas which > > >>>>> succeeded. > > >>>>>>> - trying again REBALANCELEADERS for the rest. No success. > > >>>>>>> - Shutting down nodes to force the leader to a specific replica left > > >>>>> running. > > >>>>>>> No success. > > >>>>>>> - calling REBALANCELEADERS responds that the replica is inactive!!! > > >>>>>>> - calling CLUSTERSTATUS reports that the replica is active!!! > > >>>>>>> > > >>>>>>> Also, the replica which don't want to become leader is not in the > > >>> list > > >>>>>>> of collections->[collection_name]->leader_elect->shard1..x- > >election > > >>>>>>> > > >>>>>>> Where is CLUSTERSTATUS getting it's state info from? > > >>>>>>> > > >>>>>>> Has anyone else problems with REBALANCELEADERS? > > >>>>>>> > > >>>>>>> I noticed that the Reference Guide writes "preferredLeader" (with > > >>>>> capital "L") > > >>>>>>> but the JAVA code has "preferredleader". > > >>>>>>> > > >>>>>>> Regards, Bernd > > >>>>>> > > >>>>> > > >>>> > > >>> > > >
