I sent this request to "ServerA" in this case, which became the leader of all shards. As far as I know you're supposed to issue this call to just one server as it issues the calls to the other leaders/replicas in the background, right?
I am expecting the single collections API call to spread the leaders evenly across SOLR instances. Hopefully I am just doing/expecting something wrong :). Tim Vaillancourt -----Original Message----- From: Upayavira [mailto:u...@odoko.co.uk] Sent: Thursday, February 21, 2013 1:44 PM To: solr-user@lucene.apache.org Subject: Re: Is it possible to manually select a shard leader in a running SolrCloud? Which of your three hosts did you point this request at? Upayavira On Thu, Feb 21, 2013, at 09:13 PM, Vaillancourt, Tim wrote: > Correction, I used this curl: > > curl -v > 'http://<HOST>:8983/solr/admin/collections?action=CREATE&name=test&numShards=3&replicationFactor=2&maxShardsPerNode=2' > > So 3 instances, 3 shards, 2 replicas per shard. ServerA becomes leader > of all 3 shards in 4.1 with this call. > > Tim Vaillancourt > > -----Original Message----- > From: Vaillancourt, Tim [mailto:tvaillanco...@ea.com] > Sent: Thursday, February 21, 2013 11:27 AM > To: solr-user@lucene.apache.org; markrmil...@gmail.com > Subject: RE: Is it possible to manually select a shard leader in a > running SolrCloud? > > Thanks Mark, > > The real driver for me wanting to promote a different leader is when I > create a new Collection via the Collections API across a multi-server > SolrCloud, the leader of each shard is always the same host, so you're > right that I'm tackling the wrong problem with this request, although > it would fix it for me. > > If I create the cores manually via the cores API, one-by-one, I am > able to get what I expect, but when running this Collections API call > on a 3 SOLR 4.1 instance, 3 shard setup, 1 server becomes the leader > of all 3 shards, meaning it will get all the writes for everything > (correct me if I am wrong). If so, this will not scale well with all > writes to one node (or correct me if I am wrong)? > > curl -v > 'http://<HOST>:8983/solr/admin/collections?action=CREATE&name=test&numShards=3&replicationFactor=1&maxShardsPerNode=2' > > Currently on my 3 instance SOLR 4.1 setup, the above call creates the > following: > > - ServerA is the leader of all 3 shards (the problem I want to address). > - ServerB + ServerC are automagically replicas of the 3 leader shards > on ServerA. > > So again, my issue is one server gets all the writes. Does anyone else > encounter this? If so, I should spawn a separate thread on my specific > issue. > > Cheers, > > Tim > > -----Original Message----- > From: Mark Miller [mailto:markrmil...@gmail.com] > Sent: Tuesday, February 19, 2013 8:44 PM > To: solr-user@lucene.apache.org > Subject: Re: Is it possible to manually select a shard leader in a > running SolrCloud? > > You can't easily do it the way it's implemented in ZooKeeper. We would > probably internally have to do the same thing - elect a new leader and > drop him until the one we wanted came up. The main thing doing it > internally would gain is that you could skip the elected guy from > becoming the actual leader and just move on to the next candidate. > Still some tricky corner cases to deal with and such as well. > > I think for most things you would use this to solve, there is probably > an alternate thing that should be addressed. > > - Mark > > On Mon, Feb 18, 2013 at 4:15 PM, Vaillancourt, Tim > <tvaillanco...@ea.com> > wrote: > > Hey all, > > > > I feel having to unload the leader core to force an election is "hacky", > > and as far as I know would still leave which node becomes the Leader to > > chance, ie I cannot guarantee "NodeX" becomes Leader 100% in all cases. > > > > Also, this imposes additional load temporarily. > > > > Is there a way to force the winner of the Election, and if not, is there a > > known feature-request for this? > > > > Cheers, > > > > Tim Vaillancourt > > > > -----Original Message----- > > From: Joseph Dale [mailto:joey.d...@gmail.com] > > Sent: Sunday, February 03, 2013 7:42 AM > > To: solr-user@lucene.apache.org > > Subject: Re: Is it possible to manually select a shard leader in a running > > SolrCloud? > > > > With solrclound all cores are collections. The collections API it just a > > wrapper to call the core api a million times with one command. > > > > to > > /solr/admin/cores?action=CREATE&name=core1&collection=core1&shard=1 > > > > Basically your "creating" the shard again, after leader props have gone > > out. Solr will check ZK and find a core meeting that description, then > > simply get a copy of the index from the leader of that shard. > > > > > > On Feb 3, 2013, at 10:37 AM, Brett Hoerner <br...@bretthoerner.com> wrote: > > > >> What is the inverse I'd use to re-create/load a core on another > >> machine but make sure it's also "known" to SolrCloud/as a shard? > >> > >> > >> On Sat, Feb 2, 2013 at 4:01 PM, Joseph Dale <joey.d...@gmail.com> wrote: > >> > >>> > >>> To be more clear lets say bob it the leader of core 1. On bob do a > >>> /admin/cores?action=unload&name=core1. This removes the core/shard > >>> from bob, giving the other servers a chance to grab leader props. > >>> > >>> -Joey > >>> > >>> On Feb 2, 2013, at 11:27 AM, Brett Hoerner <br...@bretthoerner.com> wrote: > >>> > >>>> Hi, > >>>> > >>>> I have a 5 server cluster running 1 collection with 20 shards, > >>> replication > >>>> factor of 2. > >>>> > >>>> Earlier this week I had to do a rolling restart across the > >>>> cluster, this worked great and the cluster stayed up the whole > >>>> time. The problem is > >>> that > >>>> the last node I restarted is now the leader of 0 shards, and is > >>>> just holding replicas. > >>>> > >>>> I've noticed this node has abnormally high load average, while > >>>> the other nodes (who have the same number of shards, but more > >>>> leaders on > >>>> average) > >>> are > >>>> fine. > >>>> > >>>> First, I'm wondering if that loud could be related to being a 5x > >>>> replica and 0x leader? > >>>> > >>>> Second, I was wondering if I could somehow flag single shards to > >>> re-elect a > >>>> leader (or force a leader) so that I could more evenly distribute > >>>> how > >>> many > >>>> leader shards each physical server has running? > >>>> > >>>> Thanks. > >>> > >>> > > > > > > > > -- > - Mark >
