[ 
https://issues.apache.org/jira/browse/CASSANDRA-3085?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13092949#comment-13092949
 ] 

Sylvain Lebresne commented on CASSANDRA-3085:
---------------------------------------------

I would argue that even now a View is not meant to be updated either (we pick 
new Views but a View itself is fixed), nor does it really ensure that it 
contains the full set of sstables in a way since that set is a moving target. 
But I suppose this is just a matter of perspective on what View is, and I'm 
fine with ViewFragment. 

> Race condition in sstable reference counting
> --------------------------------------------
>
>                 Key: CASSANDRA-3085
>                 URL: https://issues.apache.org/jira/browse/CASSANDRA-3085
>             Project: Cassandra
>          Issue Type: Bug
>          Components: Core
>    Affects Versions: 1.0
>            Reporter: Jonathan Ellis
>            Assignee: Jonathan Ellis
>            Priority: Critical
>             Fix For: 1.0
>
>         Attachments: 3085-v2.txt, 3085.txt
>
>
> DataTracker gives us an atomic View of memtable/sstables, but acquiring 
> references is not atomic.  So it is possible to acquire references to an 
> SSTableReader object that is no longer valid, as in this example:
> View V contains sstables {A, B}.  We attempt a read in thread T using this 
> View.
> Meanwhile, A and B are compacted to {C}, yielding View W.  No references 
> exist to A or B so they are cleaned up.
> Back in thread T we acquire references to A and B.  This does not cause an 
> error, but it will when we attempt to read from them next.

--
This message is automatically generated by JIRA.
For more information on JIRA, see: http://www.atlassian.com/software/jira

        

Reply via email to