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Ramkumar Aiyengar commented on SOLR-5374: ----------------------------------------- This feature certainly is helpful as is, but it might not always be practical in a distributed system to have a version ordering across updates as it's likely to involve a single point of coordination if you need one. In such cases, it might just suffice for the system if the versions were just equality comparable rather than having a strict ordering -- i.e. update if the previous version equals what I expect, else reject the update. In some sense, if some external coordinator is able to guarantee a version ordering amongst updates, couldn't the same system be able to order the queue of updates to Solr? > Support user configured doc-centric versioning rules > ---------------------------------------------------- > > Key: SOLR-5374 > URL: https://issues.apache.org/jira/browse/SOLR-5374 > Project: Solr > Issue Type: Improvement > Reporter: Hoss Man > Assignee: Hoss Man > Attachments: SOLR-5374.patch > > > The existing optimistic concurrency features of Solr can be very handy for > ensuring that you are only updating/replacing the version of the doc you > think you are updating/replacing, w/o the risk of someone else > adding/removing the doc in the mean time -- but I've recently encountered > some situations where I really wanted to be able to let the client specify an > arbitrary version, on a per document basis, (ie: generated by an external > system, or perhaps a timestamp of when a file was last modified) and ensure > that the corresponding document update was processed only if the "new" > version is greater then the "old" version -- w/o needing to check exactly > which version is currently in Solr. (ie: If a client wants to index version > 101 of a doc, that update should fail if version 102 is already in the index, > but succeed if the currently indexed version is 99 -- w/o the client needing > to ask Solr what the current version) > The idea Yonik brought up in SOLR-5298 (letting the client specify a > {{\_new\_version\_}} that would be used by the existing optimistic > concurrency code to control the assignment of the {{\_version\_}} field for > documents) looked like a good direction to go -- but after digging into the > way {{\_version\_}} is used internally I realized it requires a uniqueness > constraint across all update commands, that would make it impossible to allow > multiple independent documents to have the same {{\_version\_}}. > So instead I've tackled the problem in a different way, using an > UpdateProcessor that is configured with user defined field to track a > "DocBasedVersion" and uses the RTG logic to figure out if the update is > allowed. -- This message was sent by Atlassian JIRA (v6.1#6144) --------------------------------------------------------------------- To unsubscribe, e-mail: dev-unsubscr...@lucene.apache.org For additional commands, e-mail: dev-h...@lucene.apache.org