Hi, I was excited to see some good work in having more replica types for Solr.
However, Solr documentation left me with a few questions. https://lucene.apache.org/solr/guide/7_2/shards-and-indexing-data-in-solrcloud.html#types-of-replicas This is what I could come up with: (Note that each point compares with corresponding point in each replica-type, so it's easy to compare) NRT 1) Indexes locally 2) Remains in-sync with leader, hence leader eligible 3) Queries return latest data 4) Replicates tlog or full-index depending on how far behind it is from the leader 5) Recommended when no query should return stale data ever ! 6) Penalizes the leader for full-index copy only when the replica is missing a lot of updates (configurable though). TLOG 1) Does not index locally 2) Remains in-sync with leader, hence leader eligible 3) Queries generally return stale data as it does not index locally 4) Replicates tlog to remain in sync but also does periodic full-index copy from leader to get indexed data 5) Recommended for very high throughputs at the cost of getting stale results. 6) Can penalize the leader for large full-index copies PULL 0) Same as TLOG Replica but copies only the indexed data periodically 1) Does not index locally 2) Does not remain in-sync with leader, hence not eligible for leader election 3) Queries generally return stale data as it does not index locally 4) Only does a periodic full-index copy from leader to get indexed data 5) Recommended for use with NRT or TLOG replicas only to increase read throughput at the cost of getting stale results. 6) Can penalize the leader for large full-index copies If the above is incorrect, can someone please point that out? Thanks SG
