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Kadir OZDEMIR updated PHOENIX-5795: ----------------------------------- Attachment: PHOENIX-5795.4.x-HBase-1.5.002.patch > Supporting selective queries for index rows updated concurrently > ---------------------------------------------------------------- > > Key: PHOENIX-5795 > URL: https://issues.apache.org/jira/browse/PHOENIX-5795 > Project: Phoenix > Issue Type: Sub-task > Reporter: Kadir OZDEMIR > Assignee: Kadir OZDEMIR > Priority: Critical > Attachments: PHOENIX-5795.4.x-HBase-1.5.001.patch, > PHOENIX-5795.4.x-HBase-1.5.002.patch > > Time Spent: 1h 40m > Remaining Estimate: 0h > > From the consistent indexing design (PHOENIX-5156) perspective, two or more > pending updates from different batches on the same data row are concurrent if > and only if for all of these updates the data table row state is read from > HBase under the row lock and for none of them the row lock has been acquired > the second time for updating the data table. In other words, all of them are > in the first update phase concurrently. For concurrent updates, the first two > update phases are done but the last update phase is skipped. This means the > data table row will be updated by these updates but the corresponding index > table rows will be left with the unverified status. Then, the read repair > process will repair these unverified index rows during scans. > In addition to leaving index rows unverified, the concurrent updates may > generate index row with incorrect row keys. For example, consider that an > application issues the verify first two upserts on the same row concurrently > and the second update does not include one or more of the indexed columns. > When these updates arrive concurrently to IndexRegionObserver, the existing > row state would be null for both of these updates. This mean the index > updates will be generated solely from the pending updates. The partial upsert > with missing indexed columns will generate an index row by assuming missing > indexed columns have null value, and this assumption may not true as the > other concurrent upsert may have non-null values for indexed columns. After > issuing the concurrent update, if the application attempts to read back the > row using a selective query on the index table and this selective query maps > to an HBase scan that does not scan these unverified rows due to incorrect > row keys on these rows, the application will not get the row content back > correctly. -- This message was sent by Atlassian Jira (v8.3.4#803005)