Some insights in the new replica types below: On Sat, December 8, 2018 08:42, Vadim Ivanov < vadim.iva...@spb.ntk-intourist.ru wrote:
> > From Ref guide we have: > " NRT is the only type of replica that supports soft-commits..." > "If TLOG replica does become a leader, it will behave the same as if it > was a NRT type of replica." > Does it mean, that if we do not have NRT replicas in the cluster then > autoSoftCommit section in solconfig.xml Ignored completely (even on TLOG > leader)? > No, not completely. Both TLOG and PULL nodes will periodically poll the leader for changes in index segments' files and download those segments from the leader. If hard commit max time is defined in solrconfig.xml the polling interval of each replica will be half that value. Or else if the soft commit max time is defined then the replicas will use half the soft commit max time as the interval. If neither are defined then the poll interval will be 3 seconds (hard coded). See here: https://github.com/apache/lucene-solr/blob/75b183196798232aa6f2dcaaaab117f309119053/solr/core/src/java/org/apache/solr/cloud/ReplicateFromLeader.java#L68-L77 If the TLOG is the leader it will index locally and append the doc to transaction log as a NRT node would do as well as it will synchronously replicate the data to other TLOG replicas' transaction logs (PULL nodes don't have transaction logs). But TLOG/PULL replicas doesn't support soft commits nor real time gets, afaik. > > <autoSoftCommit> > <maxTime>60000</maxTime> > </autoSoftCommit> > > Should we say that in autoCommit section openSearcher is always true in > that case? <autoCommit> <maxDocs>10000</maxDocs> <maxTime>30000</maxTime> <maxSize>512m</maxSize> <openSearcher>false</openSearcher> </autoCommit> Does it mean that new Searcher always starts on all replicas when hard commit happens on leader? Nope. Or at least, the searcher is not synchronously created. Each non leader replica will periodically fetch the index changes from the leader and open a new searcher to reflect those changes as seen here: https://github.com/apache/lucene-solr/blob/75b183196798232aa6f2dcaaaab117f309119053/solr/core/src/java/org/apache/solr/handler/IndexFetcher.java#L653 But it's important to note that the potential delay between the leader's hard commit and the other replicas fetching those changes from the leader and opening a new searcher to reflect latest changes. PS: I am still digging these new replica types so I can have misunderstood or missed some aspect of it. Regards, Edward
