Hello Erick, Sorry for the late reply. I worked with this setting a bit and it works as expected.
Indeed, I was not aware of the leader/follower task distribution and what you say shines a different light on things. Regardless, I now know about this property and can use it effectively, which I could not before. Thanks! Best regards, Koen De Groote On Mon, Oct 28, 2019 at 12:51 PM Erick Erickson <erickerick...@gmail.com> wrote: > There’s the preferredLeader property, see: > https://lucene.apache.org/solr/guide/6_6/collections-api.html > > That said, this was put in for situations where there were 100s of shards > with replicas from many shards hosted on any given machine, so it was > possible in that setup to have 100 or more leaders on a single node. > > In the usual case, the leader role doesn’t do very much extra work, and > the extra work is mostly distributing the incoming documents to the > followers during indexing (mostly I/O). During query time, the leader has > no extra duties at all. So if “heavy use” means heavy querying, it > shouldn’t make any appreciable difference. > > I would urge you to have evidence that this was worth the effort before > spending time on it. And, the “preferredLeader” property is just that, a > preference all things being equal. It’s still possible for a leader to be a > different replica, otherwise you’d defeat the whole point of trying for HA. > > For TLOG and PULL setups, the leader will always be a TLOG replica, so you > could strategically place them to get what you want. In this case, the > leader indeed has a lot more work to do than the follower so it makes more > sense. > > Best, > Erick > > > On Oct 28, 2019, at 6:13 AM, Koen De Groote <koen.degro...@limecraft.com> > wrote: > > > > Hello, > > > > I'm looking for a way to configure my collections as such that the leader > > nodes of specific collections never share the same host. > > > > This as a way to prevent several large and/or heavy-usage collections on > > the same machine. > > > > Is this something I can set in solrconfig.xml? Or are there rules for > this? > > > > Kind regards, > > Koen De Groote > >
