Nope. There is no replication, as in replication of the indexed document in the normal flow. The _raw_ document is forwarded to all replicas and upon return from the replicas, the raw document has been written to each individual transaction log on each replica. "replication" implies the _indexed_ form of the document is what's forwarded to the replicas, and that's not the case.
It's somewhat confusing, but _if_ a replica goes down, when it comes back up if it's "too far" out of date then an old-style replication of the whole index is performed. But absent that it's all raw documents forwarded to replicas from the leader. Otherwise, how could you hope that a replica could take over without loss of data? The leader could have gone down before it forwarded the docs but after it responded to the client. Best Erick On Mon, May 6, 2013 at 10:43 AM, Furkan KAMACI <furkankam...@gmail.com> wrote: > Hi Erick; > > Thanks for your answer. I have read that at somewhere: > > I believe "redirect" from replica to leader would happen only at > index time, so a doc first gets indexed to leader and from there it's > replicated to non-leader shards. > > Is that true? I want to make clear the things in my mind otherwise I want > to ask a separate question about what happens for indexing and querying at > SolrCloud. > > 2013/5/6 Shawn Heisey <s...@elyograg.org> > >> On 5/6/2013 7:55 AM, Andre Bois-Crettez wrote: >> > Excellent idea ! >> > And it is possible to use collection aliasing with the CREATEALIAS to >> > make this transparent for the query side. >> > >> > ex. with 2 collections named : >> > collection_1 >> > collection_2 >> > >> > >> /collections?action=CREATEALIAS&name=collectionalias&collections=collection_1 >> > >> > "collectionalias" is now a virtual collection pointing to collection_1. >> > >> > Index on collection_2, then : >> > >> /collections?action=CREATEALIAS&name=collectionalias&collections=collection_2 >> > >> > "collectionalias" now is an alias to collection_2. >> > >> > >> http://wiki.apache.org/solr/SolrCloud#Managing_collections_via_the_Collections_API >> >> Awesome idea, Andre! I was wondering whether you might have to delete >> the original alias before creating the new one, but a quick look at the >> issue for collection aliasing shows that this isn't the case. >> >> https://issues.apache.org/jira/browse/SOLR-4497 >> >> The wiki doesn't mention the DELETEALIAS action. I won't have time >> right now to update the wiki. >> >> Thanks, >> Shawn >> >>
