[ https://issues.apache.org/jira/browse/CASSANDRA-15367?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Benedict Elliott Smith updated CASSANDRA-15367: ----------------------------------------------- Reviewers: Blake Eggleston, Benedict Elliott Smith (was: Benedict Elliott Smith, Blake Eggleston) Blake Eggleston, Benedict Elliott Smith (was: Blake Eggleston) Status: Review In Progress (was: Patch Available) > Memtable memory allocations may deadlock > ---------------------------------------- > > Key: CASSANDRA-15367 > URL: https://issues.apache.org/jira/browse/CASSANDRA-15367 > Project: Cassandra > Issue Type: Bug > Components: Local/Commit Log, Local/Memtable > Reporter: Benedict Elliott Smith > Assignee: Benedict Elliott Smith > Priority: Normal > Fix For: 4.0, 2.2.x, 3.0.x, 3.11.x > > > * Under heavy contention, we guard modifications to a partition with a mutex, > for the lifetime of the memtable. > * Memtables block for the completion of all {{OpOrder.Group}} started before > their flush began > * Memtables permit operations from this cohort to fall-through to the > following Memtable, in order to guarantee a precise commitLogUpperBound > * Memtable memory limits may be lifted for operations in the first cohort, > since they block flush (and hence block future memory allocation) > With very unfortunate scheduling > * A contended partition may rapidly escalate to a mutex > * The system may reach memory limits that prevent allocations for the new > Memtable’s cohort (C2) > * An operation from C2 may hold the mutex when this occurs > * Operations from a prior Memtable’s cohort (C1), for a contended partition, > may fall-through to the next Memtable > * The operations from C1 may execute after the above is encountered by those > from C2 -- This message was sent by Atlassian Jira (v8.3.4#803005) --------------------------------------------------------------------- To unsubscribe, e-mail: commits-unsubscr...@cassandra.apache.org For additional commands, e-mail: commits-h...@cassandra.apache.org