[ https://issues.apache.org/jira/browse/HBASE-18294?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Eshcar Hillel updated HBASE-18294: ---------------------------------- Release Note: A region is flushed if its memory component exceeds the region flush threshold. A flush policy decides which stores to flush by comparing the size of the store to a column-family-flush threshold. If the overall size of all memstores in the machine exceeds the bounds defined by the administrator (denoted global pressure) a region is selected and flush. HBASE-18294 changes flush decisions to be based on heap-occupancy and not data (key-value) size, consistently across levels. This rolls back some of the changes by HBASE-16747. Specifically, (1) RSs, Regions and stores track their overall on-heap and off-heap occupancy, (2) A region is flushed when its on-heap+off-heap size exceeds the region flush threshold, (3) The store to be flushed is chosen based on its on-heap+off-heap size (4) At the RS level, a flush is triggered when the overall on-heap exceeds the on-heap limit, or when the overall off-heap size exceeds the off-heap limit (low/high water marks). Note that when the region flush size is set to XXmb a region flush may be triggered even before writing keys and values of size XX because the total heap occupancy of the region which includes additional metadata exceeded the threshold. > Reduce global heap pressure: flush based on heap occupancy > ---------------------------------------------------------- > > Key: HBASE-18294 > URL: https://issues.apache.org/jira/browse/HBASE-18294 > Project: HBase > Issue Type: Improvement > Affects Versions: 3.0.0 > Reporter: Eshcar Hillel > Assignee: Eshcar Hillel > Priority: Major > Fix For: 2.0.0-beta-2 > > Attachments: HBASE-18294.01.patch, HBASE-18294.01.patch, > HBASE-18294.01.patch, HBASE-18294.01.patch, HBASE-18294.01.patch, > HBASE-18294.01.patch, HBASE-18294.01.patch, HBASE-18294.02.patch, > HBASE-18294.03.patch, HBASE-18294.04.patch, HBASE-18294.05.patch, > HBASE-18294.06.patch, HBASE-18294.07.patch, HBASE-18294.07.patch, > HBASE-18294.08.patch, HBASE-18294.09.patch, HBASE-18294.10.patch, > HBASE-18294.11.patch, HBASE-18294.11.patch, HBASE-18294.12.patch, > HBASE-18294.13.patch, HBASE-18294.15.patch, HBASE-18294.16.patch, > HBASE-18294.master.01.patch, HBASE-18294.master.01.patch > > > A region is flushed if its memory component exceed a threshold (default size > is 128MB). > A flush policy decides whether to flush a store by comparing the size of the > store to another threshold (that can be configured with > hbase.hregion.percolumnfamilyflush.size.lower.bound). > Currently the implementation (in both cases) compares the data size > (key-value only) to the threshold where it should compare the heap size > (which includes index size, and metadata). -- This message was sent by Atlassian JIRA (v7.6.3#76005)