[ 
https://issues.apache.org/jira/browse/CASSANDRA-16071?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17232306#comment-17232306
 ] 

Zhao Yang commented on CASSANDRA-16071:
---------------------------------------

bq. if the value is over 100GB, log an error and revert value back to default 
of 1GB. 

lgtm.

bq. if (maxMemBytes > 100 * 1073741824)

right hand side will overflow..

bq. logger.error("{} configured as {} is above 100GB, reverting to default 
1GB", INDEX_MAX_FLUSH_MEMORY_OPTION, maxMemBytes);



> max_compaction_flush_memory_in_mb is interpreted as bytes
> ---------------------------------------------------------
>
>                 Key: CASSANDRA-16071
>                 URL: https://issues.apache.org/jira/browse/CASSANDRA-16071
>             Project: Cassandra
>          Issue Type: Bug
>          Components: Feature/SASI
>            Reporter: Michael Semb Wever
>            Assignee: Michael Semb Wever
>            Priority: Normal
>             Fix For: 4.0, 3.11.8, 4.0-beta2
>
>
> In CASSANDRA-12662, [~scottcarey] 
> [reported|https://issues.apache.org/jira/browse/CASSANDRA-12662?focusedCommentId=17070055&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-17070055]
>  that the {{max_compaction_flush_memory_in_mb}} setting gets incorrectly 
> interpreted in bytes rather than megabytes as its name implies.
> {quote}
> 1.  the setting 'max_compaction_flush_memory_in_mb' is a misnomer, it is 
> actually memory in BYTES.  If you take it at face value, and set it to say, 
> '512' thinking that means 512MB,  you will produce a million temp files 
> rather quickly in a large compaction, which will exhaust even large values of 
> max_map_count rapidly, and get the OOM: Map Error issue above and possibly 
> have a very difficult situation to get a cluster back into a place where 
> nodes aren't crashing while initilaizing or soon after.  This issue is minor 
> if you know about it in advance and set the value IN BYTES.
> {quote}



--
This message was sent by Atlassian Jira
(v8.3.4#803005)

---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]

Reply via email to