thanks! Does puts which fall inside readpoint of ongoing scan/get are preserved in HFile also or only in memstore and it blocks memstore flush until all ongoing scans are completed.
On Tue, May 17, 2016 at 5:31 AM, Stack <[email protected]> wrote: > On Mon, May 16, 2016 at 4:55 PM, Shushant Arora <[email protected] > > > wrote: > > > Hi > > > > Hbase uses MVCC for achieving consistent result for Get operations . > > To achieve MVCC it has to maintain multiple versions of same row/cells . > > How many max version of a row/cell does Hbase keeps at any time to > support > > MVCC. > > > > Since say multiple gets started one after the other and has not completed > > yet and multiple puts are also occuring in between . Thus it maintains > all > > versions whose read point is still in use ? > > > > > Yes. > > All ongoing Gets/Scans are registered on startup with their current > readpoint (see HRegion; see constructor for HRegionScannerImpl). Any Put > that falls inside the readpoint of currently ongoing Gets/Scans will be > preserved while the Get/Scan is ongoing. > > St.Ack > > > > > Thanks! > > >
