Paulo Motta created CASSANDRA-10930:
---------------------------------------

             Summary: Limit off-heap memory
                 Key: CASSANDRA-10930
                 URL: https://issues.apache.org/jira/browse/CASSANDRA-10930
             Project: Cassandra
          Issue Type: Improvement
          Components: Configuration
            Reporter: Paulo Motta
            Priority: Minor
             Fix For: 3.x


It seems the default maximum off-heap memory varies according to the JVM 
version. For oracle hotspot, this defaults to the heap size, according to 
[this|https://terracotta.org/generated/4.3.1/html/bmg-all/index.html#page/bigmemory-go-webhelp/co-tiers_configuring_offheap_store.html]
 and 
[this|http://hg.openjdk.java.net/jdk7u/jdk7u/jdk/file/55f6804b4352/src/share/classes/sun/misc/VM.java#l279].
 This may cause oomkiller to kick in if max_mem <= 2*heap.

Opening this ticket to discuss potentially limiting off-heap usage by default 
on {{cassandra-env.sh}} with the {{-XX:MaxDirectMemorySize}}, but I wouldn't 
know to which value. Or at least checking if max_mem > 2*heap.



--
This message was sent by Atlassian JIRA
(v6.3.4#6332)

Reply via email to