Not in 9x as of today, however there is some work out there to work with the dynamic reconfigurable “ensemble” mode zookeeper capabilities. See https://github.com/apache/solr/pull/2391
This is veering off of user support into more dev@ territory ;-). I am interested in having a more proscriptive “This is how to scale Solr from 1 node to 1000’s of nodes” strategy. Here is a public Miro board link to what I’m thinking: https://miro.com/app/board/o9J_lm8BmXE=/?moveToWidget=3458764558006503531&cot=14 I can imagine a future where in conjunction with each Solr server node having a set of Roles, that we may have Solr nodes that have the “coordinator” or “zookeeper” role assigned to them, and they support the dynamic reconfigurability needs of the Zookeeper ensemble. > On May 21, 2024, at 12:41 PM, DAVID MARTIN NIETO <dmart...@viewnext.com> > wrote: > > Hi all, > > I believe at leas at Solr 8x or previous there isn't any way to solve this > problem. > > You can have 5, 7 or thousands of zookeepers to improve the HA but you cannot > dynamic add or remove zookeepers from the list. So if you have for example > two servers with 2 and 3 zookeepers and one of this nodes fall dawn you will > have problems on two ways, pair number of zookeepers up if the server that > have fail down have 3 zoos and problems of leader election between the > zookepeers, > > Anyone knows if there are any way to solve this problem? Or if in 9x versions > there are any improve about it? > > Thanks a lot > Kind regards. > > > ________________________________ > David Martín Nieto > Analista Funcional > Calle Cabeza Mesada 5 > 28031, Madrid > T: +34 667 414 432 > T: +34 91 779 56 98| Ext. 3198 > E-mail: dmart...@viewnext.com <mailto:dmart...@viewnext.com> | Web: > www.viewnext.com <http://www.viewnext.com/> > ________________________________ > [https://mail.google.com/mail/u/0?ui=2&ik=72317294cd&attid=0.0.2&permmsgid=msg-f:1662155651369049897&th=171129c229429f29&view=fimg&sz=s0-l75-ft&attbid=ANGjdJ_o0Ds8_P8d7W-csq2mmc6mBGQy9hSjXsGEv15RXUutalCYzg3HQB3CByE2swcJkH3yRaLwrXkr1G81F9FpfqcPlbpRoZcainmsJjviLoypusuKOxCnOw97zuo&disp=emb] > > > ________________________________ > De: Eric Pugh <ep...@opensourceconnections.com > <mailto:ep...@opensourceconnections.com>> > Enviado: martes, 21 de mayo de 2024 18:12 > Para: users@solr.apache.org <mailto:users@solr.apache.org> > <users@solr.apache.org <mailto:users@solr.apache.org>> > Asunto: Re: SolrCloud behavior when Zookeeper has lost a quorum. > > [EXTERNO] Este correo electrónico se envió desde fuera de la organización. No > haga clic en enlaces ni abra archivos adjuntos a menos que reconozca al > remitente y sepa que el contenido es seguro > > I’ve had a lot of luck using the bats testing infrastructure to try out “what > if” situations with Solr to see what actually happens. For example, I > tested out classic leader/follower replication works when your leader is a > single node solr cloud server and your follower is a totally separate single > node cloud server! > > You may want to write some bats test that simulate these situations to > confirm/deny what folks say “should” happen. They would be great to have > for integration/regression testing as well. > >> On May 21, 2024, at 11:30 AM, Matt Kuiper <kuipe...@gmail.com> wrote: >> >> Thanks for the responses! >> >> Shawn, >> >> I believe I understood that Zookeeper does not actually handle the request. >> Thanks for the clarification as I did not word it properly. >> >> More precisely, will a SolrJ CloudSolrClient work for the purpose of >> querying SolrCloud if the ZK host list it is configured with represents a >> Zookeeper ensemble that has lost its quorum? >> >> My goal is to learn if this SolrJ client (configured via zkhost list) can >> reliably query a SolrCloud even when the ZK ensemble has lost its quorum. >> >> I have heard that Zookeeper will go into a read-only mode if quorum is >> lost. Put another way, will the SolrJ cloud client still be able to talk >> to ZK to discover the URLs required to get >> to Solr and serve queries (at least will the solrj client be given the >> latest state from the remaining ZK nodes for what was last written to >> Zookeeper)? >> >> Our company is reviewing HA/DR scenarios for SolrCloud and I am >> investigating if a SolrCloud that has lost its ZK quorum can provide any >> value for Solr queries, and how to characterize accuracy of any search >> results. >> >> Thanks for any further information you can provide. >> >> Matt >> >> On Mon, May 20, 2024 at 9:02 PM Shawn Heisey <apa...@elyograg.org.invalid> >> wrote: >> >>> On 5/20/2024 17:46, mtn search wrote: >>>> Will a SolrJ client connection (configured with a ZKhost list) to a >>>> SolrCloud still work for querying a SolrCloud when the Zookeeper ensemble >>>> has lost its quorum, but some ZK nodes remain up? I understand that >>>> indexing will not work. >>>> >>>> Follow-on - will the Solr query work to the same SolrCloud if the query >>> is >>>> sent directly to a Solr node rather than to Zookeeper? >>> >>> Requests to SolrCloud such as queries or indexing do not go through ZK, >>> ever. >>> >>> The SolrJ cloud client talks to ZK to discover the URLs required to get >>> to Solr and which of them are online at any given moment. ZK is used as >>> a central database to coordinate the cluster, it does not handle requests. >>> >>> Thanks, >>> Shawn >>> >>> > > _______________________ > Eric Pugh | Founder | OpenSource Connections, LLC | 434.466.1467 | > http://www.opensourceconnections.com > <http://www.opensourceconnections.com/><http://www.opensourceconnections.com/> > | My Free/Busy <http://tinyurl.com/eric-cal> > Co-Author: Apache Solr Enterprise Search Server, 3rd Ed > <https://www.packtpub.com/big-data-and-business-intelligence/apache-solr-enterprise-search-server-third-edition-raw> > This e-mail and all contents, including attachments, is considered to be > Company Confidential unless explicitly stated otherwise, regardless of > whether attachments are marked as such. _______________________ Eric Pugh | Founder | OpenSource Connections, LLC | 434.466.1467 | http://www.opensourceconnections.com <http://www.opensourceconnections.com/> | My Free/Busy <http://tinyurl.com/eric-cal> Co-Author: Apache Solr Enterprise Search Server, 3rd Ed <https://www.packtpub.com/big-data-and-business-intelligence/apache-solr-enterprise-search-server-third-edition-raw> This e-mail and all contents, including attachments, is considered to be Company Confidential unless explicitly stated otherwise, regardless of whether attachments are marked as such.
