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 > >> > >
