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Andrew Purtell edited comment on HBASE-13378 at 6/9/15 5:53 PM: ---------------------------------------------------------------- {quote} bq. Up to this point READ_UNCOMMITED meant: You might see partially finished rows. bq. Now it means: You might see partially finished rows, and you may not see cells that have existed when the scanner started. This sounds to me like an incompatible change for a patch release {quote} Precisely, why does this sound like an *incompatible* change? was (Author: apurtell): {quote} bq. Up to this point READ_UNCOMMITED meant: You might see partially finished rows. Now it means: You might see partially finished rows, and you may not see cells that have existed when the scanner started. This sounds to me like an incompatible change for a patch release {quote} Precisely, why does this sound like an *incompatible* change? > RegionScannerImpl synchronized for READ_UNCOMMITTED Isolation Levels > -------------------------------------------------------------------- > > Key: HBASE-13378 > URL: https://issues.apache.org/jira/browse/HBASE-13378 > Project: HBase > Issue Type: New Feature > Reporter: John Leach > Assignee: John Leach > Priority: Minor > Attachments: HBASE-13378.patch, HBASE-13378.txt > > Original Estimate: 2h > Time Spent: 2h > Remaining Estimate: 0h > > This block of code below coupled with the close method could be changed so > that READ_UNCOMMITTED does not synchronize. > {CODE:JAVA} > // synchronize on scannerReadPoints so that nobody calculates > // getSmallestReadPoint, before scannerReadPoints is updated. > IsolationLevel isolationLevel = scan.getIsolationLevel(); > synchronized(scannerReadPoints) { > this.readPt = getReadpoint(isolationLevel); > scannerReadPoints.put(this, this.readPt); > } > {CODE} > This hotspots for me under heavy get requests. -- This message was sent by Atlassian JIRA (v6.3.4#6332)