+1 for Leader-Follower. How about Publisher-Subscriber? On Wed, Jun 17, 2020 at 5:19 PM Rahul Goswami <rahul196...@gmail.com> wrote:
> +1 on avoiding SolrCloud terminology. In the interest of keeping it obvious > and simple, may I I please suggest primary/secondary? > > On Wed, Jun 17, 2020 at 5:14 PM Atita Arora <atitaar...@gmail.com> wrote: > > > I agree avoiding using of solr cloud terminology too. > > > > I may suggest going for "prime" and "clone" > > (Short and precise as Master and Slave). > > > > Best, > > Atita > > > > > > > > > > > > On Wed, 17 Jun 2020, 22:50 Walter Underwood, <wun...@wunderwood.org> > > wrote: > > > > > I strongly disagree with using the Solr Cloud leader/follower > terminology > > > for non-Cloud clusters. People in my company are confused enough > without > > > using polysemous terminology. > > > > > > “This node is the leader, but it means something different than the > > leader > > > in this other cluster.” I’m dreading that conversation. > > > > > > I like “principal”. How about “clone” for the slave role? That suggests > > > that > > > it does not accept updates and that it is loosely-coupled, only > depending > > > on the state of the no-longer-called-master. > > > > > > Chegg has five production Solr Cloud clusters and one production > > > master/slave > > > cluster, so this is not a hypothetical for us. We have 100+ Solr hosts > in > > > production. > > > > > > wunder > > > Walter Underwood > > > wun...@wunderwood.org > > > http://observer.wunderwood.org/ (my blog) > > > > > > > On Jun 17, 2020, at 1:36 PM, Trey Grainger <solrt...@gmail.com> > wrote: > > > > > > > > Proposal: > > > > "A Solr COLLECTION is composed of one or more SHARDS, which each have > > one > > > > or more REPLICAS. Each replica can have a ROLE of either: > > > > 1) A LEADER, which can process external updates for the shard > > > > 2) A FOLLOWER, which receives updates from another replica" > > > > > > > > (Note: I prefer "role" but if others think it's too overloaded due to > > the > > > > overseer role, we could replace it with "mode" or something similar) > > > > ------------------------------------------- > > > > > > > > To be explicit with the above definitions: > > > > 1) In SolrCloud, the roles of leaders and followers can dynamically > > > change > > > > based upon the status of the cluster. In standalone mode, they can be > > > > changed by manual intervention. > > > > 2) A leader does not have to have any followers (i.e. only one active > > > > replica) > > > > 3) Each shard always has one leader. > > > > 4) A follower can also pull updates from another follower instead of > a > > > > leader (traditionally known as a REPEATER). A repeater is still a > > > follower, > > > > but would not be considered a leader because it can't process > external > > > > updates. > > > > 5) A replica cannot be both a leader and a follower. > > > > > > > > In addition to the above roles, each replica can have a TYPE of one > of: > > > > 1) NRT - which can serve in the role of leader or follower > > > > 2) TLOG - which can only serve in the role of follower > > > > 3) PULL - which can only serve in the role of follower > > > > > > > > A replica's type may be changed automatically in the event that its > > role > > > > changes. > > > > > > > > I think this terminology is consistent with the current > Leader/Follower > > > > usage while also being able to easily accomodate a rename of the > > > historical > > > > master/slave terminology without mental gymnastics or the > introduction > > or > > > > more cognitive load through new terminology. I think adopting the > > > > Primary/Replica terminology will be incredibly confusing given the > > > already > > > > specific and well established meaning of "replica" within Solr. > > > > > > > > All the Best, > > > > > > > > Trey Grainger > > > > Founder, Searchkernel > > > > https://searchkernel.com > > > > > > > > > > > > > > > > On Wed, Jun 17, 2020 at 3:38 PM Anshum Gupta <ans...@anshumgupta.net > > > > > wrote: > > > > > > > >> Hi everyone, > > > >> > > > >> Moving a conversation that was happening on the PMC list to the > public > > > >> forum. Most of the following is just me recapping the conversation > > that > > > has > > > >> happened so far. > > > >> > > > >> Some members of the community have been discussing getting rid of > the > > > >> master/slave nomenclature from Solr. > > > >> > > > >> While this may require a non-trivial effort, a general consensus so > > far > > > >> seems to be to start this process and switch over incrementally, if > a > > > >> single change ends up being too big. > > > >> > > > >> There have been a lot of suggestions around what the new > nomenclature > > > might > > > >> look like, a few people don’t want to overlap the naming here with > > what > > > >> already exists in SolrCloud i.e. leader/follower. > > > >> > > > >> Primary/Replica was an option that was suggested based on what other > > > >> vendors are moving towards based on Wikipedia: > > > >> https://en.wikipedia.org/wiki/Master/slave_(technology) > > > >> , however there were concerns around the use of “replica” as that > > > denotes a > > > >> very specific concept in SolrCloud. Current terminology clearly > > > >> differentiates the use of the traditional replication model from > > > SolrCloud > > > >> and reusing the names would make it difficult for that to happen. > > > >> > > > >> There were similar concerns around using Leader/follower. > > > >> > > > >> Let’s continue this conversation here while making sure that we > > converge > > > >> without much bike-shedding. > > > >> > > > >> -Anshum > > > >> > > > > > > > > >
