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ASF subversion and git services commented on LUCENE-5438: --------------------------------------------------------- Commit 1585682 from mikemcc...@apache.org in branch 'dev/branches/lucene5438' [ https://svn.apache.org/r1585682 ] LUCENE-5438: checkpoint current [broken] state > add near-real-time replication > ------------------------------ > > Key: LUCENE-5438 > URL: https://issues.apache.org/jira/browse/LUCENE-5438 > Project: Lucene - Core > Issue Type: Improvement > Components: modules/replicator > Reporter: Michael McCandless > Assignee: Michael McCandless > Attachments: LUCENE-5438.patch, LUCENE-5438.patch > > > Lucene's replication module makes it easy to incrementally sync index > changes from a master index to any number of replicas, and it > handles/abstracts all the underlying complexity of holding a > time-expiring snapshot, finding which files need copying, syncing more > than one index (e.g., taxo + index), etc. > But today you must first commit on the master, and then again the > replica's copied files are fsync'd, because the code operates on > commit points. But this isn't "technically" necessary, and it mixes > up durability and fast turnaround time. > Long ago we added near-real-time readers to Lucene, for the same > reason: you shouldn't have to commit just to see the new index > changes. > I think we should do the same for replication: allow the new segments > to be copied out to replica(s), and new NRT readers to be opened, to > fully decouple committing from visibility. This way apps can then > separately choose when to replicate (for freshness), and when to > commit (for durability). > I think for some apps this could be a compelling alternative to the > "re-index all documents on each shard" approach that Solr Cloud / > ElasticSearch implement today, and it may also mean that the > transaction log can remain external to / above the cluster. -- This message was sent by Atlassian JIRA (v6.2#6252) --------------------------------------------------------------------- To unsubscribe, e-mail: dev-unsubscr...@lucene.apache.org For additional commands, e-mail: dev-h...@lucene.apache.org