[ https://issues.apache.org/jira/browse/HBASE-20542?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Eshcar Hillel reassigned HBASE-20542: ------------------------------------- Assignee: Eshcar Hillel > Better heap utilization for IMC with MSLABs > ------------------------------------------- > > Key: HBASE-20542 > URL: https://issues.apache.org/jira/browse/HBASE-20542 > Project: HBase > Issue Type: Sub-task > Reporter: Eshcar Hillel > Assignee: Eshcar Hillel > Priority: Major > > Following HBASE-20188 we realized in-memory compaction combined with MSLABs > may suffer from heap under-utilization due to internal fragmentation. This > jira presents a solution to circumvent this problem. The main idea is to have > each update operation check if it will cause overflow in the active segment > *before* it is writing the new value (instead of checking the size after the > write is completed), and if it is then the active segment is atomically > swapped with a new empty segment, and is pushed (full-yet-not-overflowed) to > the compaction pipeline. Later on the IMC deamon will run its compaction > operation (flatten index/merge indices/data compaction) in the background. > Some subtle concurrency issues should be handled with care. We next elaborate > on them. -- This message was sent by Atlassian JIRA (v7.6.3#76005)