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Jingyun Tian commented on HBASE-18059: -------------------------------------- [~stack] sure. Thx for your review. > The scanner order for memstore scanners are wrong > ------------------------------------------------- > > Key: HBASE-18059 > URL: https://issues.apache.org/jira/browse/HBASE-18059 > Project: HBase > Issue Type: Bug > Components: regionserver, scan, Scanners > Affects Versions: 2.0.0 > Reporter: Duo Zhang > Assignee: Jingyun Tian > Priority: Critical > Fix For: 3.0.0, 2.1.0 > > Attachments: HBASE-18059.master.001.patch > > > This is comments for KeyValueScanner.getScannerOrder > {code:title=KeyValueScanner.java} > /** > * Get the order of this KeyValueScanner. This is only relevant for > StoreFileScanners and > * MemStoreScanners (other scanners simply return 0). This is required for > comparing multiple > * files to find out which one has the latest data. StoreFileScanners are > ordered from 0 > * (oldest) to newest in increasing order. MemStoreScanner gets LONG.max > since it always > * contains freshest data. > */ > long getScannerOrder(); > {code} > As now we may have multiple memstore scanners, I think the right way to > select scanner order for memstore scanner is to ordered from Long.MAX_VALUE > in decreasing order. > But in CompactingMemStore and DefaultMemStore, the scanner order for memstore > scanner is also start from 0, which will be messed up with StoreFileScanners. -- This message was sent by Atlassian JIRA (v7.6.3#76005)